Human skin consists of two main layers, the epidermis and dermis , which are situated on top of the hypodermis , a layer of connective tissue The skin is an effective physical barrier against microbial invasion

The skin’s relatively dry environment and normal microbiota discourage colonization by transient microbes The skin’s normal microbiota varies from one region of the body to another

skin — an effective physical barrier against microbial invasion. conjunctiva of the eye — a frequent site for microbial infection, but deeper eye infections are less common; multiple types of conjunctivitis exist.

Be able to describe the major anatomical features of the skin and eyes; compare and contrast the microbiomes of various body sites, such as the hands, back, feet, and eyes; explain how microorganisms overcome defenses of skin and eyes in order to cause infection.