Chapter 4 Integumentary System Notes

Question 1

Functions of the skin

Answer 1

1) Protection 2) Water retention 3) Vitamin D synthesis 4) Sensation 5) Thermoregulation 6) Non-verbal communication 7) Blood reservoir 8 ) Secretion and absorption

Question 2

What is function does vitamin D play?

Answer 2

Leads to Calcitriol production which helps calcium absorption in the GI tract, helps phagocytes in phagocytosis, helps phagocytes produce AMPs, reduces inflammation, and regulate immune function.

Question 3

What helps to keep bacteria at bay?

Answer 3

1) Sweat and AMPs 2) Sebum has bactericidal components 3) acidic pH of sweat, and 4) Intraepidermal macrophages

Question 4

Langerhans cells

Answer 4

Components of the innate immune system that have finger like projections. recognize and respond to microbes; damage by UV radiation can limit capabilities (important application for cancer)

Question 5

Cells of the dermis (fixed and Wandering)

Answer 5

Fixed: Fibroblasts Wandering: eosinophils, macrophages, mast cells, neutrophils

Question 6

Hair follicle

Answer 6

The organ that gives rise to hair

Question 7

Epidermal Ridges

Answer 7

Form from the projection and interdigitation of the epidermis and the dermal papillae. Function: increase SA for friction, fine touch and tactile reception

Question 8

Dermatoglyphics

Answer 8

using epidermal ridges for identification purposes

Question 9

Melanin types:

Answer 9

eumelanin (brown/black); pheomelanin (yellow-red)

Question 10

Freckle types

Answer 10

Ephelides (light freckles genetic) vs. Lantigines (Dark freckles from sunburn and UV)

Question 11

Melanin Synthesis

Answer 11

AA: Tyrosine, Enzyme: Tyrosinase location of production: Melanosome Function: protection from UV and combating of free radicals; melanin is transferred to other cells via melanosomes

Question 12

Albinism vs. Vitiligo

Answer 12

Albinism - genetic loss of tyrosinase Vitiligo - defective and/or loss of melanocytes

Question 13

Types of Sudoriferous glands

Answer 13

Eccrine (Merocrine) vs Apocrine

Question 14

Eccrine

Answer 14

Merocrine (Momo is smaller, TherMO regulation) (simple, coiled, tubular) location: palms, soles Release: H20, NaCl, glucose, urea, ammonia, uric acid, use myoepithelial cells Function: thermoregulation and excretion; release by exocytosis actually

Question 15

Apocrine

Answer 15

(simple, coiled, tubular) located in the AXilla and ANal, and pubic areas. activated at puberty, emotional stress and sexual excitement, causes secretion of pheromones and sweat, not active during thermoregulatory sweating, exocytosis

Question 16

Sebacceous glands

Answer 16

holocrine, release sebum (simple, branched, acinar), associated with hair follicle except on lips and external genitalia.

Question 17

Function of Sebum

Answer 17

moisten hair and skin; antimicrobial, waterproofs stratum corneum

Question 18

ceruminous glands

Answer 18

along with sebacceous glands form wax of external ear canal along (apocrine secretion). function: protect ear from insects, microbes, and water.

Question 19

Hair growth stages

Answer 19

1) Growth - cell divide near matrix 2) regression - stop division and follicle atrophies 3) resting phase

Question 20

Loose Definition of the Integumentary System

Answer 20

1) Skin ( Epidermis (BSGLC) / dermis (Papillary layer/reticular layer) and its accessory components ( hair follicle, nails, glands)

Question 21

Uremic Frost

Answer 21

indicated end stage renal failure white skin caused by secretions ladened w/nitrogenous waste products. Presents because the kidneys can’t filter these out due to failure.

Question 22

Hyperkeratosis

Answer 22

excessive keratin in the stratum corneum; if in the palms or soles of feet it is called palmar/plantar keratosis respectively; may lack pain or sensation.

Question 23

Where is the thinnest skin located?

Answer 23

The eyelids

Question 24

What three features define connective tissue?

Answer 24

Cell type, matrix, fibers

Question 25

What important medical application do tension lines play in surgery?

Answer 25

If you cut along tension lines you have faster healing and minimize scarring. Cut parallel to the tension lines.

Question 26

Pigment types and hair color (Black/brown, Red, Blond)

Answer 26

Black/brown - eumelanin; blonde - pheomelanin; Red hair - carotene in hair

Question 27

How long is the active phase of hair growth?

Answer 27

2-5 years

Question 28

At what pace is hair growth at the active phase?

Answer 28

0.33mm/day on average

Question 29

Three phases of hair growth

Answer 29

1) Growth/active phase 2) Regression phase 3) Resting phase

Question 30

What type of connective tissue is present in the hypodermis?

Answer 30

areolar and adipose tissue

Question 31

What type of connective tissue is present in the papillary layer of the dermis?

Answer 31

loose connective tissue

Question 32

What type of connective tissue is located in the reticular layer of the dermis?

Answer 32

Dense Irregular connective tissue