Lecture 8

Question 1

The Integumentary system
Skin=
Accessory Structures=

Answer 1

-epidermis
-dermis
-hypodermis

-hair
-nails
-glands

Question 2

Cells of the Epidermis
Five epidermal cell types
1.
2.
3.
4.
5.

Answer 2

1. stem cells
2. Keratinocytes
3. Melanocytes
4. Tactile cells
5. Dendritic cells

Question 3

Stem cells

Answer 3

-undifferentiated cells that give rise to keratinocytes
-in deepest layer of epidermis (stratum basal)
-going through mitotic division

Question 4

Keratinocytes

Answer 4

great majority of epidermal cells; synthesize keratin

Question 5

Melanocytes

Answer 5

synthesize pigment melanin; shields DNA ultraviolet radiation

Question 6

Tactile cells

Answer 6

touch receptor cells associated with dermal nerve fibers

Question 7

Dendritic cells

Answer 7

macrophages originating in bone marrow that guard against pathogens

Question 8

Layers of the Epidermis
Thin skins contains ______ strata; thick skin contains ______ strata

5 layers include:
1.
2.
3.
4.
5.

Answer 8

four; five
1. Stratum corneum (surface layer)
2. Stratum lucidum
3. Stratum granulosum
4. Stratum spinous
5. Stratum basale

Question 9

Stratum corneum:
several layers (up to ___) of dead, scaly, ________ cells
-resists ________, __________, and ________

Answer 9

30; keratinized
-abrasion; penetration; water loss

Question 10

Stratum lucidum
Thin, pale layer found only in _____ skin
-keratinocytes packed with clear protein _______
-only found in……

Answer 10

thick
-eleidin
-palms of hands, soles of feet

Question 11

Stratum granulosum
_____ to _____ layers of flat keratinocytes
- cells contain dark-staining ________ granules

Answer 11

three; five
-keratohyalin

Question 12

Stratum spinosum
several layers of keratinocytes joined by ________ and __________________
-names of appearance of cells after histological preparation (spiny)
-also contains some _______ cells

Answer 12

desmosomes; tight junctions
-dendritic

Question 13

Stratum basale (deepest epidermal layer)
-single layer of ____ cells and keratinocytes
-also contains a few _________ and _______ cells

Answer 13

-stem
-melanocytes; tactile

Question 14

The Dermis
-ranges from 0.2 mm (eyelids) to 4 mm (palms, soles)
-composed mainly of _____
-Well supplies with blood vessels, sweat glands, sebaceous glands, and nerve endings
-houses _____ follicles and ______ roots
-________ of facial expression attach to dermis
-wavy, conspicuous boundary between dermis and epidermis
-Dermal ________
-Epidermal ______

Answer 14

-collagen
-hair; nail
-muscles
-papillae
-ridges

Question 15

Dermal papillae

Answer 15

upward, finger-like extensions of dermis

Question 16

Epidermal ridges

Answer 16

downward waves of epidermis

Question 17

The dermis consists of two layers
1.
2.

Answer 17

Papillary layer
Reticular layer

Question 18

Papillary layer
-Thin zone of _______ tissue in and near the dermal papilla
-allows for mobility of ______ and other defense cells
-rich in ______ blood vessels

Answer 18

-areolar
-leukocytes
-small

Question 19

Reticular layer
-thicker layer of ______________ connective tissue
-Stretch marks (striae)
-tears in the ________ fibers caused by stretching of the skin due to pregnancy or obesity

Answer 19

-dense irregular
-collagen

Question 20

Skin Color
-dark and light skin individuals have the same number of ____________ but different types of ______

Answer 20

melanocytes; melanin

Question 21

Darker skin= more _________
-melanocytes produce ______ quantities of melanin
-melanin breaks down more slowly
-melanin granules more ___________ in keratinocytes
-melanized cells seen throughout the epidermis

Answer 21

eumelanin
-greater
-spread out

Question 22

Lighter skin= more ____________
-melanin clumped near keratinocyte nucleus
-little melanin seen beyond stratum _____

Answer 22

pheomelanin
-basale

Question 23

Cyanosis

Answer 23

blueness due to oxygen deficiency

Question 24

Erythema

Answer 24

redness due to increased blood flow to skin

Question 25

Pallor

Answer 25

paleness due to decreased blood flow to skin

Question 26

Albinism

Answer 26

white skin due to genetic lack of melanin

Question 27

Jaundice

Answer 27

yellowing due to bilirubin in blood
-can be caused by compromised liver function

Question 28

Hematoma

Answer 28

bruising; clotted blood under skin