Integumentary System

Question 1

Integumentary system

Answer 1

The skin and its accessory structures; hair, nails, cutaneous glands

Question 2

Job of the Integumentary System

Answer 2

COVER AND PROTECT
Some absorptive and secretory functions
Keeps person hydrated
Vitamin D synthesis
Sensation
Non-verbal communication
Thermoregulation

Question 3

2 types of skin

Answer 3

1. Thin - majority of skin
2. Thick - palms of hands and soles of feet; 1 additional layer in epidermis provides additional protection against friction and deeper papillae to improve grip in slippery conditions

Question 4

2 layers of skin

Answer 4

Epidermis and dermis

Question 5

Epidermis

Answer 5

Very top layer of the skin
4/5 layers- Come/ Let’s/ Get Sun Burnt

Question 6

COME - Stratum Corneum

Answer 6

Most superficial layer; 8-10 layers of DEAD skin cells (bags of keratin); protective and expendable; can take wear and tear of daily life

Question 7

LET’S - Stratum Lucidum

Answer 7

Only found in thick skin; has added component eleidin = reflects light, lighter on hands and feet

Question 8

GET - Stratum Granulosum

Answer 8

3-5 layers of deep, grainy-looking cells; due to pockets (granules) of keratin

Question 9

SUN - Stratum Spinosum

Answer 9

Largest layer of the epidermis; contains many cellular junctions which leads to a spiny appearance under the microscope

Question 10

BURNT - Stratum Basale

Answer 10

“Base” layer; one cell layer thick, simple cuboidal; make more epidermal cells, mitosis happens here

Question 11

Skin cell journey

Answer 11

Basale (base) -> spinosum -> granulosum (cells mature here) -> cells die -> corneum

Question 12

Cell types of the epidermis

Answer 12

Keratinocytes
Langerhan’s cell
Merkel’s cell
Melanocytes
Stem cells

Question 13

Keratinocytes

Answer 13

Make keratin; 90% of cells in epidermis

Question 14

Langerhan’s (dendritic) cell

Answer 14

Looks like a star fish; macrophages (big eater); front line of immune system
Ameboid crawling around patrolling for something foreign; if found = engulfs the foreign body via starfish arms and wear as armor to alert the rest of the immune system (antigen presenting cell)

Question 15

Merkel’s (tactile) cell

Answer 15

Stationary and is in association with a nerve ending; sensory mechanism

Question 16

Melanocytes

Answer 16

Makes melanin (protein); brown/black in color and near the basale layer; protects the cell DNA from UV rays -> uses melanin like an umbrella to protect the cell nucleus

Question 17

Stem cells

Answer 17

Integumentary stem cells; located in the basale layer; produce new cells to travel upward

Question 18

Dermis - 3 tissue types

Answer 18

Dense irregular CT
Loose areolar CT
Adipose CT

Question 19

Dermis - Papillary Layer

Answer 19

Contain finger-like projections (superficial); loose areolar CT and fibrocytes; makes up 20% of dermis

Question 20

Dermis - Reticular Layer

Answer 20

Dense irregular CT found here; makes up 80% of the dermis; heavy on the collagen, thus it can withstand pulling

Question 21

Features of the dermis

Answer 21

Pacinian corpuscles and meissners corpuscles (sensory cells that detect pressure and vibration sensations)
Thermal receptors
Free nerve endings
Sebaceous glands originate here (oil)
Erector pilli muscle
Adipose tissue
Highly vasuclarized

Question 22

Erector pilli muscles

Answer 22

Erects the hair (pillus) when it is called for; goosebumps (cold and trying to stay warm by trapping pockets of air); fear (defensive function; cats)

Question 23

Friction ridges

Answer 23

Found in thick skin only; source of fingerprints; created by papillary extensions on top of dermal ridges; pruning when wet provides a better grip

Question 24

Hair

Answer 24

A strand of dead keratinized cells
Hair texture and color is determined by the shape of the hair shaft; genetically determined via incomplete dominance
Hair color determined by phaomelanin (reddish brown) and eumelanin (brown/black); lack of both = blonde

Question 25

Sebaceous glands

Answer 25

produce an oily substance (sebum); secreted to keep the skin moisturized and protected; associated often with hair follicles

Question 26

Suderiferous glands - 2 types

Answer 26

Both associated with watery substance - sweat
Merocrine: releases at pore directly to skin surface; found all over the body; helps with temp regulation
Apocrine: associated with hair follicles; in axillary and anogenital areas (scent glands); active at puberty and onward

Question 27

Ceruminous glands

Answer 27

Glands of the ear canal that produce wax

Question 28

Cholesterol

Answer 28

Stabilizes the permeability of the membrane; integral for vitamin D synthesis
UV in skin -> cholecalciferol (kidneys and liver) -> calciferol (active vit D)