Anatomy- The Integumentary System

Question 1

Hypodermis:

What is it composed of?

Functions?

Answer 1

Subcutaneous layer just deep to the dermis

• mostly adipose with some Areolar connective tissue
• insulates, absorbs, shocks, & anchors skin loosely to muscles.

Question 2

Epidermis

What type of tissue?

Answer 2

Keratinized stratified squamous epithelium

Question 3

Epidermis 4 distinct cell types:

Name and describe

Answer 3

1.Keratinocytes: produce the fibrous protein KERATIN
—tightly connected by desmosomes, waterproofs the
skin.

2. Melanocytes: spider-shaped cells that produce the pigment MELANIN
3. Langerhans’ cells(epidermal dendritic cells): macrophages; part of immune system.
4. Merkel Cells: a sensory receptor for touch.

Question 4

Layers of Epidermis: Thick Skin

Answer 4

Has 5 layers(strata), sole of the foot
From least to greatest:
Stratum basale, stratum spinosum, stratum granulosum, stratum lucidum & stratum corneum.

Question 5

Layers of Epidermis: Thin Skin

Answer 5

Has only 4 layers….missing stratum lucidum, stratum corneum thinner

Question 6

Stratum Basale

What does it produce?

Answer 6

Basal layer, deepest epidermal layer firmly attached to dermis.

• single layer of cells; cell division produces new keratinocytes for all layers

Question 7

Dermis

What is it composed of?
What does it contain?

Answer 7

Strong connective tissue

-fibroblasts, , macrophages, mast cells & white blood cells with collagen, elastin & reticular layers.

Question 8

Dermis- papillary layer

-What is it composed of?

Answer 8

Upper layer composed of Areolar connective tissue

Question 9

Dermis- reticular layer

-What is it composed of?

Answer 9

Lower layer(most thickness of the dermis)

Composed of dense irregular tissue.

Question 10

Skin Color ( name 3 pigments)

Answer 10

1. Melanin- Gives color to skin, hair, eyes. Protects cell nucleus from UV light
2. Carotene- yellow-orange pigment. Most evident in thick skin.
3. Hemoglobin- oxygenated hemoglobin in dermal capillaries gives fair skin a pinkish color.

Question 11

2 types of sweat glands

Answer 11

Eccrine and apocrine.

Question 12

Eccrine sweat glands

Answer 12

Far more numerous- most abundant on palms of hands, soles of feet and forehead

Secretes sweat: 99% water with salts, vitamin C

Question 13

Apocrine sweat glands

Answer 13

Ducts empty into hair follicles

Made of sweat, lipid and proteins.

Question 14

Ceremonious Glands

Answer 14

Modified apocrine glands in the external ear canal

-Ear wax

Question 15

Sebaceous(oil)glands

Answer 15

Secret sebum(rich in oils) into hair follicle(or pore), lubricates hair and skin.

Question 16

Hair(pili)

Answer 16

Made of dead keratinized cells.

Melanin produces color in the hair.

Question 17

Hair- alopecia

Answer 17

Hair loss brought by aging and hormones.

Question 18

The skin is composed of 2 regions:

Name and describe them

Answer 18

Epidermis: outermost layer composed of epithelial cells

Dermis: underlying layer composed of fibrous connective tissue