Body Membranes & Skin: Integumentary System

Chapter 4

Body Membranes

• Function of body membranes– Cover body surfaces– Line body cavities– Form protective sheets around organs

2 types of membranes

• Epithelial membranes– Cutaneous membranes– Mucous membranes– Serous membranes

• Connective tissue membranes– Synovial membranes

Epithelial Membrane: Cutaneous membrane

• Skin– Epidermis- stratified

squamous– Dermis- dense

connective tissue

Epithelial Membrane: Mucous membrane

• Lines all body cavities that are open to the outside of the body

Epithelial Membrane: Serous membrane

• Lines body cavities that are closed to outside of body– Peritoneum- abdominal

cavity, evolved from coelom

– Pleura- around the lungs– Pericardium- around the

heart

Saggital section: peritoneum in green

Connective tissue membrane: Synovial membrane

• Lines cavity between joints

Integumentary System

• Skin (cutaneous membrane)

• Skin Derivatives– Sweat glands– Oil glands– Hair– Nails

Skin

• Functions:– protection of deeper

tissues from chemicals, bacteria, and drying.

– Regulates body temp– makes vitamin D.– Contains sensory

receptors.

Skin

• Epidermis– stratified squamous

epithelial tissue, no blood supply

• Dermis– dense connective tissue– blood vessels, nerves,

skin appendages, produce fingerprints

Skin Color

• Pigment= melanin• Amount of melanin

depends on genetics & exposure to sunlight

Is a zebra black with white stripes or white with black stripes?

Sebaceous Glands

• Produce oil– Keeps skin from drying

out– Kills bacteria

• Acne is an infection of the sebaceous gland

Sweat Glands

• Produce sweat that dumps into pores or hair follicles

• Sweat= water, salt, fatty acids, urea

• Acidic to kill bacteria• Bacteria is what causes

sweat odor

Fun (Smelly) Fact

• The bacteria in your armpits are more closely related to the bacteria in your friend’s armpits than the bacteria in your own pubic area.

Fun Fact

• On a hot day you can lose up to 7 liters of water

X 7