integumentary system

Question 1

4 cells types present in epidermis

Answer 1

keratinocytes, melanocytes, langerhans, merkel

Question 2

keratinocytes

Answer 2

produce keratin- hardens and waterproofs skin. mature keratinocytes at the skin surface are dead and filled almost entirely with keratin

Question 3

melanocytes

Answer 3

produce melanin, a pigment that protects the cells from ultraviolet radiation. Melanin from the melanocytes is transferred to the keratinocytes

Question 4

langerhans cells

Answer 4

phagocytic macrophages that interact with white blood cells during an immune response

Question 5

merkel cells

Answer 5

occur deep in the epidermis at the epidermal-dermal boundary. They form Merkel discs which in association w nerve endings, serve a sensory function.

Question 6

stratum corneum

Answer 6

many layers of dead, anucleate keratinocytes completely filled with keratin. The outermost layers are constantly shed

Question 7

stratum lucidum

Answer 7

2-3 layers of anucleate cells. Layer is usually apparant only in thick skin (palms of hands and soles of feet)

Question 8

stratum granulosum

Answer 8

2-4 layers of cells held together by desmosomes. Cells contain keratohyaline granulaes, which contribute to the formation of keratin in the upper layers of the epidermis

Question 9

stratum spinosum

Answer 9

8-10 layers of cells connected by desmosomes. The cells are moderately active in mitosis

Question 10

stratum basale

Answer 10

contains a single layer of columnar cells actively dividing by mitosis to produce cells that migrate into the upper epidermal layers and ultimately to the surface of the skin

Question 11

dermis consists of various connective tissues…

Answer 11

It contains fibroblasts and macrophages within a gelatinous matrix containing collagen, elastic, and reticular fibers. The structure provides strength, extensibility (ability to be stretched), and elasticity (the ability to return to its original form)

Question 12

2 layers of dermis

Answer 12

Papillary layer is a thin, outer layer with fingerlike projections called dermal papillae that protrude into the epidermis. In the hands and feet the dermal papillae generate epidermal ridges
The reticular layer is a thick layer below that makes up most of the dermis

Question 13

hypodermis

Answer 13

subcutaneous layer, mostly adipose tissue and is the storage site of most body fat. Fastens the skin to the underlying surface, provide thermal insulation, and absorb shocks from impacts to the skin

Question 14

Hair matrix

Answer 14

Bottom of the hair follicle (located within the bulb). Cells are actively dividing, producing new hair cells. As these cells differentiate, they produce keratin and absorb melanin from nearby melanocytes. Color of hair is determined by the pigments absorbed from the melanocytes.

Question 15

Nails

Answer 15

keratinized epithelial cells. Semilunar lighter region of the nail, the lanula, is the area of new nail growth.

Question 16

4 kinds of sudoriferous (sweat) glands

Answer 16

Eccrine
Apocrine
Ceruminous
Mammary

Question 17

Eccrine glands

Answer 17

Occur under most skin surfaces and secrete a watery solution through pores, which serve to cool the skin as it evaporates

Question 18

Apocrine glands

Answer 18

occur under skin surfaces of the armpits and pubic regions and beginning with puberty secrete a solution in response to stress or sexual excitement. The solution is more viscous than that secreted by eccrine glands and is secreted into hair follicles

Question 19

Ceruminous glands

Answer 19

secrete cerumen (earwax) into the external ear canal. Wax helps to impede the entrance of foreign bodies

Question 20

Mammary glands

Answer 20

produce milk that is secreted through the nipples of the breast

Question 21

Sebaceous glands

Answer 21

secrete sebum, an oily substance into hair follicles or sometimes through skin surface pores. Inhibits bacterial growth and helps prevent drying of hair and skin.