Chapter 5 - The Integumentary System

Question 1

Structures of the integument

Answer 1

-Skin
-Hair
-Nails
-Glands

Question 2

Functions of the integument

Answer 2

-Protection (against UVs, microbes, abrasion)
-Sensation (pressure, temperature, touch, pain sensory receptors)
-Temperature regulation
-Vitamin D production
-Excretion (small amount of waste removal)

Question 3

Dermis

Answer 3

Thick layer of connective tissue

Question 4

Subcutaneous tissue

Answer 4

-Loose CT that connects skin to underlying structures
-NOT part of skin!
-AKA hypodermis

Question 5

Epidermis major features

Answer 5

-Avascular (nourished through diffusion)
-Layers (strata) of epithelial cells
-Separated from dermis by basement membrane

Question 6

Epidermal cell types

Answer 6

-Keratinocytes
-Melanocytes
-Langerhan cells
-Merkel cells

Question 7

Langerhan cells

Answer 7

Part of the immune system

Question 8

Merkel cells

Answer 8

Detect light, touch, and superficial pressure

Question 9

Keratinization

Answer 9

As cells move superficially, they fill with keratin, die, and serve as a layer that resists abrasion/forms a permeability layer

Question 10

Stratum spinosum

Answer 10

-Limited cell division
-Contains desmosomes, lamellar bodies, and additional keratin fibers

Question 11

Stratum granulosum

Answer 11

-In superficial layers, nucleus/other organelles degenerate, cell dies
-Contains keratohyalin

Question 12

Thick skin

Answer 12

-All 5 layers of strata
-Areas of high abrasion (palms, fingertips, soles)
-Fingerprints and footprints (papillae of underlying dermis)

Question 13

Thin skin

Answer 13

-4 strata (no Stratum lucidum)
-More flexible than thick skin
-Hair can grow here

Question 14

Skin color determining factors

Answer 14

-Pigment (melanin, carotene pigment from vegetables)
-Blood circulation
-Thickness of stratum corneum

Question 15

Cyanosis

Answer 15

Blue color in skin due to decrease in blood oxygen content

Question 16

Erythema

Answer 16

Red color in skin due to an increase in blood flow

Question 17

Stratum basale

Answer 17

-Single layer cubodial or columnar cells
-Anchors epidermis to basement membrane with hemidesmosomes
-Keratinocyte stem cells

Question 18

Dermis composition

Answer 18

-CT
-Many fibers, fibroblasts, macrophages,
-Some adipocytes and blood vessels
-Also contains nerves, hair follicles, smooth muscle, glands, and lymphatic vessels

Question 19

Papillary layer

Answer 19

-Superficial 1/5
-Areolar with lots of elastic fibers, dermal papillae, capillary beds
-Touch receptors, nerve endings that sense pain

Question 20

Reticular layer

Answer 20

-Deeper 4/5
-Dense irregular CT with collagen and elastic fibers
-Contains some adipose, hair follicles, nerves, oil glands, ducts of sweat glands, and heat sensors

Question 21

Cleavage/tension lines

Answer 21

Elastic and collagen fibers oriented in some directions more than others

Question 22

Subcutaneous tissue cell types

Answer 22

-Adipose
-Fibroblasts
-Macrophages

Question 23

Subcutaneous tissue functions

Answer 23

-Energy source
-Insulation
-Padding

Question 24

Dermis nerve ending types

Answer 24

-Free nerve endings
-Hair follicle receptors (light touch)
-Meissner corpuscles (2-point sensation)
-Pacinian corpuscles (deep pressure)
-Ruffini end organs (continuous touch or pressure)

Question 25

Hair components

Answer 25

-Root -Shaft -Concentric layers (deep to superficial): Medulla, cortex, cuticle -Hair follicle -Hair bulb -Arrector pili

Question 26

Hair follicle

Answer 26

-Dermal root sheath -External root sheath (internal contains stratum basal, is visible as white bulb, may remain/source new epithelial cells, and external)

Question 27

Hair bulb

Answer 27

-Contains internal matrix: source of hair -Dermis projects in as hair papillae, provides blood supply

Question 28

Sebaceous glands

Answer 28

-Holocrine -Oily secretion (sebum) -Prevents drying, may inhibit bacteria -Most empty into a hair follicle

Question 29

Eccrine glands

Answer 29

-AKA merocrine -Most common -Simple coiled tubular -Have own pores (open directly onto surface) -Produce isotonic fluid (sweat) -Numerous in palms and soles

Question 30

Apocrine glands

Answer 30

-Active at puberty -Compound coiled tubular -Usually open to hair follicles (but superficial to sebaceous glands) -Found in axillae, genitalia, around anus

Question 31

Ceruminous glands

Answer 31

-Modified merocrine sweat glands -Produce cerumen (ear wax)

Question 32

Mammary glands

Answer 32

-Modified apocrine sweat glands -Produce milk

Question 33

Nail structure

Answer 33

-Nail body (stratum corneum) -Eponychium/cuticle (corneum superficial to nail body (hyponychium is corneum beneath free edge)) -Matrix (cells give rise to nail) -Nail bed (cells give rise to nail) -Nail root (extends)

Question 34

Vitamin D production

Answer 34

-Vitamin D aids in Ca+ and PO4-2 adsorption from intestines, release from bones, reduces loss from kidneys -Ca+ helps bone health, clotting, and nerve/muscle function -7-dehydrocholesterol converts to cholecalciferol in skin, cholecalciferol is sent to liver and kidneys where it is converted to active vitamin D

Question 35

Effects of Aging

Answer 35

-Skin more easily damaged (epidermis thins, collagen levels decrease) -Wrinkling (decrease in elastic fibers) -Poor temperature regulation (decrease in blood supply) -Functioning melanocytes decrease or increase