Chapter 1

An Introduction to the Human Body

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Summary

Human anatomy is the scientific study of the body’s structures. The word “anatomy” comes from a Greek root that means “to cut apart.” Human anatomy was first studied by observing the exterior of the body and observing the wounds of soldiers and other injuries. Dissection is still used in medical schools, anatomy courses, and in pathology labs. When a body is dissected, its structures are cut apart in order to observe their physical attributes and their relationships to one another.

Key terms

body

dissected, its structures are cut apart in order to observe their physical attributes and their relationships to one another

section

in anatomy, a single flat surface of a three-dimensional structure that has been cut through

anatomy

science that studies the form and composition of the body’s structures

negative feedback

homeostatic mechanism that tends to stabilize an upset in the body’s physiological condition by preventing an excessive response to a stimulus, typically as the stimulus is removed

oblique plane

two-dimensional, vertical plane that intersects the body at an angle and is not parallel of perpendicular to any of the other three commonly used planes

positron emission tomography (PET)

medical imaging technique in which radiopharmaceuticals are traced to reveal metabolic and physiological functions in tissues

set point

ideal value for a physiological parameter; the level or small range within which a physiological parameter such as blood pressure is stable and optimally healthful, that is…

computed tomography (CT)

medical imaging technique in which a computer-enhanced cross-sectional X-ray image is obtained

Chapter 2

The Chemical Level of Organization

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Summary

An object’s mass and its weight are related concepts, but not quite the same. An object’s mass is the amount of matter contained in the object, and the object’s mass is the same whether that object is on Earth or in the zero-gravity environment of outer space. Where gravity strongly pulls on an object’s mass its weight is greater than it is where gravity is less strong. The substance of the universe—from a grain of sand to a star—is called matter .

Key terms

ion

atom with an overall positive or negative charge

object’s mass

the amount of matter contained in the object, and the object’s mass is the same whether that object is on Earth or in the zero-gravity environment of outer space

object’s mass its weight

greater than it is where gravity is less strong

matter

physical substance; that which occupies space and has mass

object’s mass and its weight

related concepts, but not quite the same

decomposition reaction

type of catabolic reaction in which one or more bonds within a larger molecule are broken, resulting in the release of smaller molecules or atoms

hydrogen bond

dipole-dipole bond in which a hydrogen atom covalently bonded to an electronegative atom is weakly attracted to a second electronegative atom

Chapter 3

The Cellular Level of Organization

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Summary

The phosphate group is negatively charged, making the head polar and hydrophilic—or “water loving.” A hydrophilic molecule (or region of a molecule) is one that is attracted to water. Despite differences in structure and function, all living cells in multicellular organisms have a surrounding cell membrane. As the outer layer of your skin separates your body from its environment, the cell membrane (also known as the plasma membrane) separates the inner contents of a cell from its exterior environment. This cell membrane provides a protective barrier around the cell and regulates which materials can pass in or out

Key terms

phosphate group

negatively charged, making the head polar and hydrophilic—or “water loving.” A hydrophilic molecule (or region of a molecule) is one that is attracted to water

cell membrane

membrane surrounding all animal cells, composed of a lipid bilayer interspersed with various molecules; also known as plasma membrane

hydrophilic

describes a substance or structure attracted to water

anticodon

consecutive sequence of three nucleotides on a tRNA molecule that is complementary to a specific codon on an mRNA molecule

cytoplasm

internal material between the cell membrane and nucleus of a cell, mainly consisting of a water-based fluid called cytosol, within which are all the other organelles and cellular…

mitosis

division of genetic material, during which the cell nucleus breaks down and two new, fully functional, nuclei are formed

peripheral protein

membrane-associated protein that does not span the width of the lipid bilayer, but is attached peripherally to integral proteins, membrane lipids, or other components of the…

stem cell

cell that is oligo-, multi-, or pleuripotent that has the ability to produce additional stem cells rather than becoming further specialized

Chapter 4

The Tissue Level of Organization

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Summary

The term tissue is used to describe a group of cells found together in the body. Microscopic observation reveals that the cells in a tissue share morphological features and are arranged in an orderly pattern that achieves the tissue’s functions. Relate the structure of each tissue type to their function The cells within a tissue share a common embryonic origin.

Key terms

tissue

group of cells that are similar in form and perform related functions

tissue share morphological features and

arranged in an orderly pattern that achieves the tissue’s functions

term tissue

used to describe a group of cells found together in the body

mesothelium

simple squamous epithelial tissue which covers the major body cavities and is the epithelial portion of serous membranes

primary union

condition of a wound where the wound edges are close enough to be brought together and fastened if necessary, allowing quicker and more thorough healing

smooth muscle

under involuntary control, moves internal organs, cells contain a single nucleus, are spindle-shaped, and do not appear striated; each cell is a fiber

muscle tissue

type of tissue that is capable of contracting and generating tension in response to stimulation; produces movement

matrix

extracellular material which is produced by the cells embedded in it, containing ground substance and fibers

Chapter 5

The Integumentary System

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Summary

The epidermis is composed of keratinized, stratified squamous epithelium. The skin and its accessory structures make up the integumentary system , which provides the body with overall protection. The deeper layer of skin is well vascularized (has numerous blood vessels). Although you may not typically think of the skin as an organ, it is in fact made of tissues that work together as a single structure to perform unique and critical functions.

Key terms

integumentary system

skin and its accessory structures

skin

made of multiple layers of cells and tissues, which are held to underlying structures by connective tissue ( Figure 5.2 )

dermis

layer of skin between the epidermis and hypodermis, composed mainly of connective tissue and containing blood vessels, hair follicles, sweat glands, and other structures

keratin

type of structural protein that gives skin, hair, and nails its hard, water-resistant properties

deeper layer of skin

well vascularized (has numerous blood vessels)

epidermis

outermost tissue layer of the skin

arrector pili

smooth muscle that is activated in response to external stimuli that pull on hair follicles and make the hair “stand up”

eleiden

clear protein-bound lipid found in the stratum lucidum that is derived from keratohyalin and helps to prevent water loss

Chapter 6

Bone Tissue and the Skeletal System

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Summary

The skeletal system is the body system composed of bones and cartilage and performs the following critical functions for the human body Just as the steel beams of a building provide a scaffold to support its weight, the bones and cartilage of your skeletal system compose the scaffold that supports the rest of your body. Bone , or osseous tissue , is a hard, dense connective tissue that forms most of the adult skeleton, the support structure of the body. In the areas of the skeleton where bones move (for example, the ribcage and joints), cartilage , a semi-rigid form of connective tissue, provides flexibility and smooth surfaces for movement.

Key terms

skeletal system

organ system composed of bones and cartilage that provides for movement, support, and protection

bone

hard, dense connective tissue that forms the structural elements of the skeleton

cartilage

semi-rigid connective tissue found on the skeleton in areas where flexibility and smooth surfaces support movement

osseous tissue

bone tissue; a hard, dense connective tissue that forms the structural elements of the skeleton

remodeling

process by which osteoclasts resorb old or damaged bone at the same time as and on the same surface where osteoblasts form new bone to replace that which is resorbed

modeling

process, during bone growth, by which bone is resorbed on one surface of a bone and deposited on another

short bone

cube-shaped bone that is approximately equal in length, width, and thickness; provides limited motion

diploë

layer of spongy bone, that is sandwiched between the two layers of compact bone found in flat bones

Chapter 7

Axial Skeleton

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Summary

The primary functions of the skeleton are to provide a rigid, internal structure that can support the weight of the body against the force of gravity, and to provide a structure upon which muscles can act to produce… The lower portion of the skeleton is specialized for stability during walking or running. The skeleton consists of the bones of the body. For adults, there are 206 bones in the skeleton.

Key terms

axial skeleton

central, vertical axis of the body, including the skull, vertebral column, and thoracic cage

lower portion of the skeleton

specialized for stability during walking or running

anulus fibrosus

tough, fibrous outer portion of an intervertebral disc, which is strongly anchored to the bodies of the adjacent vertebrae

coccyx

small bone located at inferior end of the adult vertebral column that is formed by the fusion of four coccygeal vertebrae; also referred to as the “tailbone”

nasal conchae

curved bony plates that project from the lateral walls of the nasal cavity; include the superior and middle nasal conchae, which are parts of the ethmoid bone, and the…

paranasal sinuses

cavities within the skull that are connected to the conchae that serve to warm and humidify incoming air, produce mucus, and lighten the weight of the skull; consist of frontal…

Chapter 8

The Appendicular Skeleton

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Summary

This consists of two bones, the scapula and clavicle ( Figure 8.3 ). The clavicle (collarbone) is an S-shaped bone located on the anterior side of the shoulder. The lateral end of the clavicle articulates (joins) with the scapula just above the shoulder joint. The bones that attach each upper limb to the axial skeleton form the pectoral girdle (shoulder girdle).

Key terms

clavicle

collarbone; elongated bone that articulates with the manubrium of the sternum medially and the acromion of the scapula laterally

pectoral girdle

shoulder girdle; the set of bones, consisting of the scapula and clavicle, which attaches each upper limb to the axial skeleton

scapula

shoulder blade bone located on the posterior side of the shoulder

clavicle (collarbone)

an S-shaped bone located on the anterior side of the shoulder

carpal bone

one of the eight small bones that form the wrist and base of the hand; these are grouped as a proximal row consisting of (from lateral to medial) the scaphoid, lunate…

coronoid fossa

depression on the anterior surface of the humerus above the trochlea; this space receives the coronoid process of the ulna when the elbow is maximally flexed

olecranon fossa

large depression located on the posterior side of the distal humerus; this space receives the olecranon process of the ulna when the elbow is fully extended

radial fossa

small depression located on the anterior humerus above the capitulum; this space receives the head of the radius when the elbow is maximally flexed

Chapter 9

Joints

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Summary

A joint , also called an articulation , is any place where adjacent bones or bone and cartilage come together (articulate with each other) to form a connection. The structural classification of joints is based on whether the articulating surfaces of the adjacent bones are directly connected by fibrous connective tissue or cartilage, or whether the articulating surfaces contact… Structural classifications of joints take into account whether the adjacent bones are strongly anchored to each other by fibrous connective tissue or cartilage, or whether the adjacent bones articulate with each other… The amount of movement available at a particular joint of the body is related to the functional requirements for that joint.

Key terms

joint

site at which two or more bones or bone and cartilage come together (articulate)

structural classification of joints

based on whether the articulating surfaces of the adjacent bones are directly connected by fibrous connective tissue or cartilage, or whether the articulating surfaces co

adjacent bones

strongly anchored to each other by fibrous connective tissue or cartilage, or whether the adjacent bones articulate with each other…

particular joint of the body

related to the functional requirements for that joint

circumduction

circular motion of the arm, thigh, hand, thumb, or finger that is produced by the sequential combination of flexion, abduction, extension, and adduction

eversion

foot movement involving the intertarsal joints of the foot in which the bottom of the foot is turned laterally, away from the midline

joint cavity

space enclosed by the articular capsule of a synovial joint that is filled with synovial fluid and contains the articulating surfaces of the adjacent bones

Chapter 10

Muscle Tissue

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Summary

This occurs in striated muscle (skeletal and cardiac) after specific binding sites on the actin have been exposed in response to the interaction between calcium ions (Ca ++ ) and proteins (troponin and tropomyosin)… Muscle is one of the four primary tissue types of the body, and the body contains three types of muscle tissue: skeletal muscle, cardiac muscle, and smooth muscle ( Figure 10.2 ). Ca ++ also is required for the contraction of smooth muscle, although its role is different: here Ca ++ activates enzymes, which in turn activate myosin heads. While the nervous system can influence the excitability of cardiac and smooth muscle to some degree, skeletal muscle completely depends on signaling from the nervous system to work properly.

Key terms

cardiac muscle

striated muscle found in the heart; joined to one another at intercalated discs and under the regulation of pacemaker cells, which contract as one unit to pump blood through the…

skeletal muscle

striated, multinucleated muscle that requires signaling from the nervous system to trigger contraction; most skeletal muscles are referred to as voluntary muscles that move bones…

smooth muscle

nonstriated, mononucleated muscle in the skin that is associated with hair follicles; assists in moving materials in the walls of internal organs, blood vessels, and internal…

Ca ++

removed and the actin-binding sites are re-shielded

myosin

protein that makes up most of the thick cylindrical myofilament within a sarcomere muscle fiber

tropomyosin

regulatory protein that covers myosin-binding sites to prevent actin from binding to myosin

actin

protein that makes up most of the thin myofilaments in a sarcomere muscle fiber

Chapter 11

The Muscular System

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Summary

To lift a cup, a muscle called the biceps brachii is actually the prime mover; however, because it can be assisted by the brachialis, the brachialis is called a synergist in this action ( Figure 11.2 ). The moveable end of the muscle that attaches to the bone being pulled is called the muscle’s insertion , and the end of the muscle attached to a fixed (stabilized) bone is called the origin . To move the skeleton, the tension created by the contraction of the fibers in most skeletal muscles is transferred to the tendons. The tendons are strong bands of dense, regular connective tissue that connect muscles to bones.

Key terms

muscle called the biceps brachii

actually the prime mover; however, because it can be assisted by the brachialis, the brachialis is called a synergist in this action ( Figure 11.2 )

insertion

end of a skeletal muscle that is attached to the structure (usually a bone) that is moved when the muscle contracts

origin

end of a skeletal muscle that is attached to another structure (usually a bone) in a fixed position

agonist

(also, prime mover) muscle whose contraction is responsible for producing a particular motion

bone connection

why this muscle tissue is called skeletal muscle

biceps brachii

two-headed muscle that crosses the shoulder and elbow joints to flex the forearm while assisting in supinating it and flexing the arm at the shoulder

tendons

strong bands of dense, regular connective tissue that connect muscles to bones

brachialis

muscle deep to the biceps brachii that provides power in flexing the forearm

Chapter 12

The Nervous System and Nervous Tissue

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Summary

The central nervous system (CNS) is the brain and spinal cord, and the peripheral nervous system (PNS) is everything else ( Figure 12.2 ). Relate the functional and structural differences between gray matter and white matter structures of the nervous system to the structure of neurons The picture you have in your mind of the nervous system probably includes the brain , the nervous tissue contained within the cranium, and the spinal cord , the extension of nervous tissue within the vertebral column. That suggests it is made of two organs—and you may not even think of the spinal cord as an organ—but the nervous system is a very complex structure.

Key terms

nervous system

composed of many organs that all look similar and can only be differentiated using tools such as the microscope or electrophysiology

neuron

neural tissue cell that is primarily responsible for generating and propagating electrical signals into, within, and out of the nervous system

peripheral nervous system (PNS)

anatomical division of the nervous system that is largely outside the cranial and vertebral cavities, namely all parts except the brain and spinal cord

brain

the large organ of the central nervous system composed of white and gray matter, contained within the cranium and continuous with the spinal cord

central nervous system (CNS)

anatomical division of the nervous system located within the cranial and vertebral cavities, namely the brain and spinal cord

gray matter

regions of the nervous system containing cell bodies of neurons with few or no myelinated axons; actually may be more pink or tan in color, but called gray in contrast to white…

spinal cord

organ of the central nervous system found within the vertebral cavity and connected with the periphery through spinal nerves; mediates reflex behaviors

white matter

regions of the nervous system containing mostly myelinated axons, making the tissue appear white because of the high lipid content of myelin

Chapter 13

Anatomy of the Nervous System

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Summary

Many structures that appear to be adjacent in the adult brain are not connected, and the connections that exist may seem arbitrary. The brain is a complex organ composed of gray parts and white matter, which can be hard to distinguish. Relate the different stages of development to the adult structures of the central nervous system Starting from an embryologic perspective allows you to understand more easily how the parts relate to each other.

Key terms

brain

a complex organ composed of gray parts and white matter, which can be hard to distinguish

basal forebrain

nuclei of the cerebrum related to modulation of sensory stimuli and attention through broad projections to the cerebral cortex, loss of which is related to Alzheimer’s disease

basal nuclei

nuclei of the cerebrum (with a few components in the upper brain stem and diencephalon) that are responsible for assessing cortical movement commands and comparing them with the…

Broca’s area

region of the frontal lobe associated with the motor commands necessary for speech production and located only in the cerebral hemisphere responsible for language production…

cerebellum

region of the adult brain connected primarily to the pons that developed from the metencephalon (along with the pons) and is largely responsible for comparing information from…

cerebrum

region of the adult brain that develops from the telencephalon and is responsible for higher neurological functions such as memory, emotion, and consciousness

circle of Willis

unique anatomical arrangement of blood vessels around the base of the brain that maintains perfusion of blood into the brain even if one component of the structure is blocked or…

Chapter 14

The Somatic Nervous System

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Summary

A major role of sensory receptors is to help us learn about the environment around us, or about the state of our internal environment. The stimulus causes the sensory cell to produce an action potential that is relayed into the central nervous system (CNS), where it is integrated with other sensory information—or sometimes higher cognitive… Describing sensory function with the term sensation or perception is a deliberate distinction. Sensation is the activation of sensory receptor cells at the level of the stimulus.

Key terms

receptor cell

cell that transduces environmental stimuli into neural signals

term sensation or perception

a deliberate distinction

capsaicin

molecule that activates nociceptors by interacting with a temperature-sensitive ion channel and is the basis for “hot” sensations in spicy food

cochlear duct

space within the auditory portion of the inner ear that contains the organ of Corti and is adjacent to the scala tympani and scala vestibuli on either side

cone photoreceptor

one of the two types of retinal receptor cell that is specialized for color vision through the use of three photopigments distributed through three separate populations of cells

dorsal stream

connections between cortical areas from the occipital to parietal lobes that are responsible for the perception of visual motion and guiding movement of the body in relation to…

Chapter 15

The Autonomic Nervous System

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Summary

The two divisions of the autonomic nervous system are the sympathetic division and the parasympathetic division . The nervous system can be divided into two functional parts: the somatic nervous system and the autonomic nervous system. The somatic nervous system is associated with voluntary responses (though many can happen without conscious awareness, like breathing), and the autonomic nervous system is associated with involuntary responses, such as… The somatic nervous system causes contraction of skeletal muscles.

Key terms

autonomic nervous system

instrumental in homeostatic mechanisms in the body

somatic nervous system

associated with voluntary responses (though many can happen without conscious awareness, like breathing), and the autonomic nervous system is associated with involuntary

parasympathetic division

division of the autonomic nervous system responsible for restful and digestive functions

sympathetic division

division of the autonomic nervous system associated with the fight-or-flight response

cardiovascular center

region in the medulla that controls the cardiovascular system through cardiac accelerator nerves and vasomotor nerves, which are components of the sympathetic division of the…

central neuron

specifically referring to the cell body of a neuron in the autonomic system that is located in the central nervous system, specifically the lateral horn of the spinal cord or a…

collateral ganglia

ganglia outside of the sympathetic chain that are targets of sympathetic preganglionic fibers, which are the celiac, inferior mesenteric, and superior mesenteric ganglia

craniosacral system

alternate name for the parasympathetic division of the autonomic nervous system that is based on the anatomical location of central neurons in brain-stem nuclei and the lateral…

Chapter 16

The Neurological Exam

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Summary

The first of these is the mental status exam , which assesses the higher cognitive functions such as memory, orientation, and language. Two major sections, the sensory exam and the motor exam , test the sensory and motor functions associated with spinal nerves. The neurological exam is a clinical assessment tool used to determine what specific parts of the CNS are affected by damage or disease. Then there is the cranial nerve exam , which tests the function of the 12 cranial nerves and, therefore, the central and peripheral structures associated with them.

Key terms

neurological exam

clinical assessment tool that can be used to quickly evaluate neurological function and determine if specific parts of the nervous system have been affected by damage or disease

exam

a series of subtests separated into five major sections

cranial nerve exam

major section of the neurological exam that assesses sensory and motor functions of the cranial nerves and their associated central and peripheral structures

first of these

the mental status exam , which assesses the higher cognitive functions such as memory, orientation, and language

sensory exam

major section of the neurological exam that assesses sensory functions of the spinal cord and spinal nerves

motor exam

major section of the neurological exam that assesses motor functions of the spinal cord and spinal nerves

mental status exam

major section of the neurological exam that assesses cognitive functions of the cerebrum

convergence

in vision, the movement of the eyes so that they are both pointed at the same point in space, which increases for stimuli that are closer to the subject

Chapter 17

The Endocrine System

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Summary

In the human body, two major organ systems participate in relatively “long distance” communication: the nervous system and the endocrine system. Once the neurotransmitters interact (bind) with receptors on the receiving (post-synaptic) cell, the receptor stimulation is transduced into a response such as continued electrical signaling or modification of cellular… Communication is a process in which a sender transmits signals to one or more receivers to control and coordinate actions. Together, these two systems are primarily responsible for maintaining homeostasis in the body

Key terms

endocrine system

cells, tissues, and organs that secrete hormones as a primary or secondary function and play an integral role in normal bodily processes

receptor stimulation

transduced into a response such as continued electrical signaling or modification of cellular…

adrenal glands

endocrine glands located at the top of each kidney that are important for the regulation of the stress response, blood pressure and blood volume, water homeostasis, and…

pancreas

organ with both exocrine and endocrine functions located posterior to the stomach that is important for digestion and the regulation of blood glucose

thymus

organ that is involved in the development and maturation of T-cells and is particularly active during infancy and childhood

thyroxine

(also, tetraiodothyronine, T 4 ) amino acid-derived thyroid hormone that is more abundant but less potent than T 3 and often converted to T 3 by target cells

osmoreceptor

hypothalamic sensory receptor that is stimulated by changes in solute concentration (osmotic pressure) in the blood

antidiuretic hormone (ADH)

hypothalamic hormone that is stored by the posterior pituitary and that signals the kidneys to reabsorb water

Chapter 18

The Cardiovascular System: Blood

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Summary

The cellular elements—referred to as the formed elements —include red blood cells (RBCs) , white blood cells (WBCs) , and cell fragments called platelets . The extracellular matrix, called plasma , makes blood unique among connective tissues because it is fluid. The primary function of blood is to deliver oxygen and nutrients to and remove wastes from body cells, but that is only the beginning of the story. Recall that blood is a connective tissue.

Key terms

blood

liquid connective tissue composed of formed elements—erythrocytes, leukocytes, and platelets—and a fluid extracellular matrix called plasma; component of the cardiovascular system

formed elements

cellular components of blood; that is, erythrocytes, leukocytes, and platelets

plasma

in blood, the liquid extracellular matrix composed mostly of water that circulates the formed elements and dissolved materials throughout the cardiovascular system

white blood cells (WBCs)

(also, leukocytes) one of the formed elements of blood that provides defense against disease agents and foreign materials

platelets

(also, thrombocytes) one of the formed elements of blood that consists of cell fragments broken off from megakaryocytes

red blood cells (RBCs)

(also, erythrocytes) one of the formed elements of blood that transports oxygen

foods you eat

absorbed in the digestive tract

Chapter 19

The Cardiovascular System: The Heart

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Summary

Relate the structure of the heart to its function as a pump Trace the pathway of oxygenated and deoxygenated blood thorough the chambers of the heart The vital importance of the heart is obvious. If one assumes an average rate of contraction of 75 contractions per minute, a human heart would contract approximately 108,000 times in one day, more than 39 million times in one year, and nearly 3 billion times…

Key terms

atrioventricular valves

one-way valves located between the atria and ventricles; the valve on the right is called the tricuspid valve, and the one on the left is the mitral or bicuspid valve

ejection fraction

portion of the blood that is pumped or ejected from the heart with each contraction; mathematically represented by SV divided by EDV

Frank-Starling mechanism

relationship between ventricular stretch and contraction in which the force of heart contraction is directly proportional to the initial length of the muscle fiber

isovolumic contraction

(also, isovolumetric contraction) initial phase of ventricular contraction in which tension and pressure in the ventricle increase, but no blood is pumped or ejected from the heart

sulcus

(plural = sulci) fat-filled groove visible on the surface of the heart; coronary vessels are also located in these areas

ventricle

one of the primary pumping chambers of the heart located in the lower portion of the heart; the left ventricle is the major pumping chamber on the lower left side of the heart…

cardiac notch

depression in the medial surface of the superior lobe of the left lung where the apex of the heart is located

atrioventricular septum

cardiac septum located between the atria and ventricles; atrioventricular valves are located here

Chapter 20

The Cardiovascular System: Blood Vessels and Circulation

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Summary

Eventually, the smallest arteries, vessels called arterioles, further branch into tiny capillaries, where nutrients and wastes are exchanged, and then combine with other vessels that exit capillaries to form venules… Arteries and veins transport blood in two distinct circuits: the systemic circuit and the pulmonary circuit ( Figure 20.2 ). Pulmonary veins then return freshly oxygenated blood from the lungs to the heart to be pumped back out into systemic circulation. An artery is a blood vessel that carries blood away from the heart, where it branches into ever-smaller vessels.

Key terms

pulmonary veins

two sets of paired vessels, one pair on each side, that are formed from the small venules leading away from the pulmonary capillaries that flow into the left atrium

pulmonary circuit

system of blood vessels that provide gas exchange via a network of arteries, veins, and capillaries that run from the heart, through the body, and back to the lungs

artery

blood vessel that conducts blood away from the heart; may be a conducting or distributing vessel

arteriole

(also, resistance vessel) very small artery that leads to a capillary

venule

small vessel leading from the capillaries to veins

vein

blood vessel that conducts blood toward the heart

adrenal vein

drains the adrenal or suprarenal glands that are immediately superior to the kidneys; the right adrenal vein enters the inferior vena cava directly and the left adrenal vein…

aortic sinuses

small pockets in the ascending aorta near the aortic valve that are the locations of the baroreceptors (stretch receptors) and chemoreceptors that trigger a reflex that aids in…

Chapter 21

The Lymphatic and Immune System

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Summary

The lymphatic system, for most people, is associated with the immune system to such a degree that the two systems are virtually indistinguishable. The swelling of lymph nodes during an infection and the transport of lymphocytes via the lymphatic vessels are but two examples of the many connections between these critical organ systems The lymphatic system is the system of vessels, cells, and organs that carries excess fluids to the bloodstream and filters pathogens from the blood. A major function of the lymphatic system is to drain body fluids and return them to the bloodstream.

Key terms

immune system

series of barriers, cells, and soluble mediators that combine to response to infections of the body with pathogenic organisms

lymph

fluid contained within the lymphatic system

lymphatic system

network of lymphatic vessels, lymph nodes, and ducts that carries lymph from the tissues and back to the bloodstream

lymphocytes

white blood cells characterized by a large nucleus and small rim of cytoplasm

lymphatic vessels

but two examples of the many connections between these critical organ systems

lymph node

one of the bean-shaped organs found associated with the lymphatic vessels

IgA

antibody whose dimer is secreted by exocrine glands, is especially effective against digestive and respiratory pathogens, and can pass immunity to an infant through breastfeeding

Chapter 22

The Respiratory System

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Summary

Functionally, the respiratory system can be divided into a conducting zone and a respiratory zone. The major organs of the respiratory system function primarily to provide oxygen to body tissues for cellular respiration, remove the waste product carbon dioxide, and help to maintain acid-base balance. The conducting zone of the respiratory system includes the organs and structures not directly involved in gas exchange. Portions of the respiratory system are also used for non-vital functions, such as sensing odors, speech production, and for straining, such as during childbirth or coughing ( Figure 22.2 )

Key terms

respiratory system

also used for non-vital functions, such as sensing odors, speech production, and for straining, such as during childbirth or coughing ( Figure 22.2 )

conducting zone

region of the respiratory system that includes the organs and structures that provide passageways for air and are not directly involved in gas exchange

respiratory zone

includes structures of the respiratory system that are directly involved in gas exchange

ala

(plural = alae) small, flaring structure of a nostril that forms the lateral side of the nares

lung

organ of the respiratory system that performs gas exchange

alar cartilage

cartilage that supports the apex of the nose and helps shape the nares; it is connected to the septal cartilage and connective tissue of the alae

alveolar duct

small tube that leads from the terminal bronchiole to the respiratory bronchiole and is the point of attachment for alveoli

central chemoreceptor

one of the specialized receptors that are located in the brain that sense changes in hydrogen ion, oxygen, or carbon dioxide concentrations in the brain

Chapter 23

The Digestive System

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Summary

The function of the digestive system is to break down the foods you eat, release their nutrients, and absorb those nutrients into the body. Rather, this blood is diverted to the liver where its nutrients are off-loaded for processing before blood completes its circuit back to the heart. Although the small intestine is the workhorse of the system, where the majority of digestion occurs, and where most of the released nutrients are absorbed into the blood or lymph, each of the digestive system organs… As is the case with all body systems, the digestive system does not work in isolation; it functions cooperatively with the other systems of the body.

Key terms

liver

largest gland in the body whose main digestive function is the production of bile

liver where its nutrients

off-loaded for processing before blood completes its circuit back to the heart

small intestine

section of the alimentary canal where most digestion and absorption occurs

body

mid-portion of the stomach

tongue

accessory digestive organ of the mouth, the bulk of which is composed of skeletal muscle

rectal valve

one of three transverse folds in the rectum where feces is separated from flatus

pylorus

lower, funnel-shaped part of the stomach that is continuous with the duodenum

Chapter 24

Metabolism and Nutrition

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Summary

If the net energy change is positive (catabolic reactions release more energy than the anabolic reactions use), then the body stores the excess energy by building fat molecules for long-term storage. On the other hand, if the net energy change is negative (catabolic reactions release less energy than anabolic reactions use), the body uses stored energy to compensate for the deficiency of energy released by catabolism Conversely, anabolic reactions use the energy produced by catabolic reactions to synthesize larger molecules from smaller ones, such as when the body forms proteins by stringing together amino acids. Because catabolic reactions produce energy and anabolic reactions use energy, ideally, energy usage would balance the energy produced.

Key terms

metabolism

sum of all catabolic and anabolic reactions that take place in the body

net energy change

positive (catabolic reactions release more energy than the anabolic reactions use), then the body stores the excess energy by building fat molecules for long-term storage

catabolic reactions

reactions that break down larger molecules into their constituent parts

anabolic reactions

reactions that build smaller molecules into larger molecules

absorptive state

also called the fed state; the metabolic state occurring during the first few hours after ingesting food in which the body is digesting food and absorbing the nutrients

bile salts

salts that are released from the liver in response to lipid ingestion and surround the insoluble triglycerides to aid in their conversion to monoglycerides and free fatty acids

body mass index (BMI)

relative amount of body weight compared to the overall height; a BMI ranging from 18-24.9 is considered normal weight, 25-29.9 is considered overweight, and greater than 30 is…

electron transport chain (ETC)

ATP production pathway in which electrons are passed through a series of oxidation-reduction reactions that forms water and produces a proton gradient

Chapter 25

The Urinary System

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Summary

The glomerulus is the first part of the nephron, which then continues as a highly specialized tubular structure responsible for creating the final urine composition. The urinary system’s ability to filter the blood resides in about 2 to 3 million tufts of specialized capillaries—the glomeruli—distributed more or less equally between the two kidneys. Because the glomeruli filter the blood based mostly on particle size, large elements like blood cells, platelets, antibodies, and albumen are excluded. All other solutes, such as ions, amino acids, vitamins, and wastes, are filtered to create a filtrate composition very similar to plasma.

Key terms

glomerulus

tuft of capillaries surrounded by Bowman’s capsule; filters the blood based on size

aquaporin

protein-forming water channels through the lipid bilayer of the cell; allows water to cross; activation in the collecting ducts is under the control of ADH

brush border

formed by microvilli on the surface of certain cuboidal cells; in the kidney it is found in the PCT; increases surface area for absorption in the kidney

inulin

plant polysaccharide injected to determine GFR; is neither secreted nor absorbed by the kidney, so its appearance in the urine is directly proportional to its filtration rate

leaky tight junctions

tight junctions in which the sealing strands of proteins between the membranes of adjacent cells are fewer in number and incomplete; allows limited intercellular movement of…

osteomalacia

softening of bones due to a lack of mineralization with calcium and phosphate; most often due to lack of vitamin D; in children, osteomalacia is termed rickets; not to be…

sacral micturition center

group of neurons in the sacral region of the spinal cord that controls urination; acts reflexively unless its action is modified by higher brain centers to allow voluntary…

vasa recta

branches of the efferent arterioles that parallel the course of the loops of Henle and are continuous with the peritubular capillaries; with the glomerulus, form a portal system

Chapter 26

Fluid, Electrolyte, and Acid-Base Balance

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Summary

The dissolved substances in a solution are called solutes. Contrast the composition of the intracellular fluid with that of the extracellular fluid The chemical reactions of life take place in aqueous solutions. In the human body, solutes vary in different parts of the body, but may include proteins—including those that transport lipids, carbohydrates, and, very importantly, electrolytes.

Key terms

fluid compartment

fluid inside all cells of the body constitutes a compartment system that is largely segregated from other systems

antidiuretic hormone (ADH)

also known as vasopressin, a hormone that increases the volume of water reabsorbed from the collecting tubules of the kidney

extracellular fluid (ECF)

fluid exterior to cells; includes the interstitial fluid, blood plasma, and fluids found in other reservoirs in the body

plasma osmolality

ratio of solutes to a volume of solvent in the plasma; plasma osmolality reflects a person’s state of hydration

dihydroxyvitamin D

active form of vitamin D required by the intestinal epithelial cells for the absorption of calcium

respiratory alkalosis

condition wherein a deficiency of carbonic acid/CO 2 levels causes the blood to be overly alkaline

respiratory acidosis

condition wherein an excess of carbonic acid or CO 2 causes the blood to be overly acidic

Chapter 27

The Reproductive System

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Summary

At fertilization, the chromosomes in one male gamete, called a sperm (or spermatozoon), combine with the chromosomes in one female gamete, called an ovum. The paired testes are a crucial component in this process, as they produce both sperm and androgens, the hormones that support male reproductive physiology. In almost all sexually reproducing species, these two haploid cells differ in size; the smaller gamete is called the male gamete and the larger one is called the female gamete. Unique for its role in reproduction, a gamete is a specialized sex cell, which in humans carries 23 chromosomes—one half the number in body cells.

Key terms

smaller gamete

called the male gamete and the larger one is called the female gamete

paired testes

a crucial component in this process, as they produce both sperm and androgens, the hormones that support male reproductive physiology

gamete

haploid reproductive cell that contributes genetic material to form an offspring

ovum

haploid female gamete resulting from completion of meiosis II at fertilization

sperm

(also, spermatozoon) male gamete

testes

(singular = testis) male gonads

secondary sex characteristics

physical characteristics that are influenced by sex steroid hormones and have supporting roles in reproductive function

epididymis

(plural = epididymides) coiled tubular structure in which sperm start to mature and are stored until ejaculation

Chapter 28

Development and Inheritance

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Summary

Fertilization occurs when a sperm and an oocyte (egg) combine and their nuclei fuse. This new single cell, called a zygote , contains all of the genetic material needed to form a human—half from each biological parent Because each of these reproductive cells is a haploid cell containing half of the genetic material needed to form a human being, their combination forms a diploid cell. During ejaculation, hundreds of millions of sperm (spermatozoa) are released into the vagina.

Key terms

zygote

fertilized egg; a diploid cell resulting from the fertilization of haploid gametes from the male and female lines

fertilization

unification of genetic material from male and female haploid gametes

acrosome

cap-like vesicle located at the anterior-most region of a sperm that is rich with lysosomal enzymes capable of digesting the protective layers surrounding the oocyte

blastocyst

term for the conceptus at the developmental stage that consists of about 100 cells shaped into an inner cell mass that is fated to become the embryo and an outer trophoblast that…

Braxton Hicks contractions

weak and irregular peristaltic contractions that can occur in the second and third trimesters; they do not indicate that childbirth is imminent

brown adipose tissue

highly vascularized fat tissue that is packed with mitochondria; these properties confer the ability to oxidize fatty acids to generate heat

capacitation

process that occurs in the female reproductive tract in which sperm are prepared for fertilization; leads to increased motility and changes in their outer membrane that improve…

foremilk

watery, translucent breast milk that is secreted first during a feeding and is rich in lactose and protein; quenches the infant’s thirst