CHAPTER 5

Question 1

Functions of Skin

Answer 1

A. protection
B. Homeostasis of Body Temps
C. Cutaneous Sensation
D Metabolic Functions
E. Blood Reservoir
F. Excretion

Question 2

Protection

Answer 2

1. Physical/mechanical: water resistant
2. Chemical barriers; low ph secretions, sweat, sebum, antibiotics, melanin
3. Biological; dendrite cellls, macrophages, DNA

Question 3

Homeostasis

Answer 3

Vasodilation, vasoconstriction, sweat gland secretions

Question 4

Vasodilation

Answer 4

dilation of blood cells. when its hot, blood is brouth closer to the external environment and heat is transfered to the water molecules of sweat

Question 5

Vasoconstriction

Answer 5

narrowing of dermal blood vessels; external temp drops

Question 6

Cutaneous Sensation

Answer 6

pacinian corpuscles
meissners corpuscles
markel cells
hair follicle receptors
free nerve endings

Question 7

Pacinian copuscles

Answer 7

detect deep pressure

Question 8

meissner’s corpuscles

Answer 8

detect touch

Question 9

merkel cells

Answer 9

detect caresses

Question 10

hairl follicle receptors

Answer 10

detect movement of hair

Question 11

Free nerve endings

Answer 11

detect pain

Question 12

Skin Structure

Answer 12

^ Epidermis: avascular
> Dermis: vascularized
v Hypodermis: vascular

Question 13

Epidermal Layers

Answer 13

Stratum Corneum
stratum Lucidum
stratum granulosum
stratum spinosum
stratum basal

Question 14

Stratum corneum

Answer 14

outer layer of single-like keratinized cells w/thick membranes, about 75% of epidermal thickness, waterproofing and protection from penetration/abrasion

Question 15

Stratum Lucidum

Answer 15

Thin and transrosw of clear flat dead keratinocytes, visible only in thick skin

Question 16

stratum granulosum

Answer 16

thin layer, keratinization begins- cells fill with keratin, cells flatten, nuclei and organelles start disintegrating, plasma membrane thickens, keratohyaline fill cytoplasm

Question 17

Stratum Spinosum

Answer 17

several layers of keratinocytes held together by desmosomes, contain weblike system of intermediate filaments, resist tension, abundant melanin granules and langerhans cells

Question 18

Stratum Basale

Answer 18

deepest layer, single row of youngest keratinocytes and melanocytes, keratinocytes undergo rapid division

Question 19

Dermal layers

Answer 19

papillary and reticular

Question 20

Papillary layer

Answer 20

areolar CT; collagen and ellastic fibers
Dermal papillae- papillary loops, free nerve endings, meisseners corpuscle
Epidermal Ridges- finger prints

Question 21

Reticular Layer

Answer 21

80% of dermis

dense fibrous connective tissue, contains glands nerves, hair follicle etc.

Question 22

Hypodermis

Answer 22

Subcutaneous layer

• adipose
• store fat
• anchors skin to underlying structures

Question 23

Skin Color

Answer 23

Melanin: yellow to tan or reddish brown to black
Carotene: orange
Hemoglobin: pinkish

Question 24

Sebaceous Gland

Answer 24

secrete sebum, can kill bacteria, base of hair follicle

Question 25

Eccrine/merocrine sweat glands

Answer 25

palms, pads, heads

Question 26

Apocrine sweat glands

Answer 26

axillary and anogenital regions (armpits, pubic region), secrete proteins and lipids

Question 27

Ceruminous glands

Answer 27

ear cannals- ear wax (cerumen)

Question 28

Types of skin cancer

Answer 28

Basal cell Carcinoma
squamous cell carcinoma
malignant melanoma

Question 29

Basal Cell Carcinoma

Answer 29

almost never metastasize beyond original tumor site

Question 30

Squamous cell carcinoma

Answer 30

epidermis, caused by UV

Question 31

Malignant Melanoma

Answer 31

cancer in melanocytes; can beginn wherever there is pigment. life threatening