NOTES – INTEGUMENTARY SYSTEM PART 3

Which layer of the Integumentary System is mostly loose connective tissue and adipose tissue? The hypodermis is mostly loose connective tissue and adipose tissue. Which layer of skin is where most cell division occurs? The dermis is the layer of skin where most cell division occurs. What is the top layer of skin called? The top layer of skin is called the epidermis. Which layer of the dermis is the deepest? The deepest layer of the dermis is the reticular layer.

Which layer of the dermis is responsible for fingerprints? The papillary layer is the layer of the dermis responsible for fingerprints. Which layer of the epidermis have cells undergone a chemical change and formed layers (sometimes 25 layers thick)? The layer of the epidermis that has undergone a chemical change and formed layers is the stratum corneum or keratinized layer.

Which layer of the epidermis is the stratum where most cell division occurs? The layer of the epidermis where most cell division occurs is the stratum basale. Which layer of the epidermis is the stratum where dandruff, calluses, and corns occur? The layer of the epidermis where dandruff, calluses and corns occur is the stratum corneum. What is the pigment called that gives our skin its color? What is the cell that produces this pigment? The pigment that gives our skin its color is melanin and the cell that produces this pigment is a melanocyte.

Where is hair produced? Hair is produced by a hair bulb on a papilla in the dermis. What determines hair color? Melanin determines hair color. What causes goosebumps? Arrector pili muscles cause goosebumps. What are the two types of sweat glands? The two types of sweat glands are eccrine and apocrine glands. Where are the sweat glands located? Eccrine are located all over the body while apocrine glands are located in the axillae and genital area.

What gland is usually responsible for acne? The sebaceous gland is responsible for acne.

Functions of the Integumentary System Protection water loss, microbes, foreign objects Temperature Regulation maintains homeostasis Vitamin D Production used by bones and muscles Sensation (sense of touch) sensory nerve receptors in dermis & epidermis Excretion small amount of waste, fluid

The Effects of Aging on Skin blood flow to the skin is reduced skin becomes thinner & more transparent less elastin & fat causes wrinkles less collagen – more easily damaged age spots, discoloration, gray hairs

Damage to the Skin: Burns, Cancer, Disease 1st Degree affects epidermis only

2nd Degree Burn affects epidermis and part of dermis

3rd Degree Burn epidermis, dermis, most nerve endings completely destroyed

Skin Cancer BASAL CELL CARCINOMA most frequent type of skin cancer begins in stratum basale and goes into dermis treatment: surgery or radiation does not metastasize

SQUAMOUS CELL CARCINOMA cells above statum basale can metastasize & cause death

MALIGNANT MELANOMA from melanocytes in a mole can metastasize & cause death

DISEASES OF THE SKIN Acne infection involving hair follicle & sebaceous gland also can have a significant hormonal cause

Viral Infections caused by a virus carried to the skin by blood EX: measles (rubella), chicken pox

Warts & Cold Sores also caused by a virus relatively harmless, could lead to other conditions