Lecture Integumentary System

Question 1

What does the integumentary system consist of?

Answer 1

the integumentary system consists of skin and its accessory structures

Question 2

What are accessory structures?

Answer 2

hair
nails
glands
sensory receptors

Question 3

outer, more dead layer = ____
inner, more alive layer = ____

Answer 3

outer, more dead layer = epidermis
inner, more alive layer = dermis

Question 4

Function of integumentary system?

Answer 4

protective covering
barrier against harmful substances & microorganisms
regulates body temperature
limits evaporation (water loss)
contains sensory receptors
excretes some waste

Question 5

Two layers of epidermis we need to know and a description of them?

Answer 5

Epidermis:
consists of up to 5 layers – we just need to know outer- and inner-most layers:

consists of stratified squamous epithelium
stratum corneum: consists of dead, flattened, keratinized cells

stratum basale: single row of cuboidal/columnar epithelial cells that are mitotically active; constantly regenerates epidermis

Question 6

What causes skin resiliency?

Answer 6

skin’s resiliency is due to the protein keratin

Question 7

What is keratin?

Answer 7

keratin – tough, fibrous waterproof protein found in skin and accessory structures

Question 8

Keratinization?

Answer 8

keratinization occurs when keratin hardens and becomes dehydrated (loses water) and accumulates in the outermost portion of the epidermis (stratum corneum)

Question 9

What is pigment in skin?
What is it produced by?
What is its functino?

Answer 9

the pigmentation of skin is due to the pigment melanin

produced by cells located in the stratum basale called melanocytes

melanin helps protect against DNA-damaging ultraviolet radiation found in natural light

Question 10

Where is the dermis located?
What are descriptions of its layers?

Answer 10

the dermis is located beneath the epidermis and consists of two main layers:

papillary dermis: composed of loose connective tissue
features undulating ridges which give rise to unique fingerprints
features nerve-endings which detect light touch

reticular dermis: consists of dense connective tissue

Question 11

accessory structures originate from the ____, extend into ____ or ____

Answer 11

accessory structures originate from the epidermis, extend into dermis or hypodermis

Question 12

Accessory structures of the skin?

Answer 12

hair follicles
nails
skin glands (sweat and sebaceous)

Question 13

Why is it important for accessory structures to remain intact when skin is damaged?

Answer 13

if accessory structures remain intact, injured/burned dermis can regenerate

Question 14

Where is hair present?

Answer 14

Hair is present on all surfaces of skin except palms, soles, lips, nipples, parts of external reproductive organs

Question 15

What is hair follicle?

Answer 15

Hair follicle: Tube-like depression of epidermal cells from which hair develops

Extends into dermis or the subcutaneous layer

Question 16

Three parts of hair?

Answer 16

Hair bulb (dividing cells)
Hair root
Hair shaft (dead, epidermal cells)

Question 17

____ ____contains blood vessels to nourish hair

Hair color is due to type and amount of ____

____ ____ ____ causes (goosebumps)

Answer 17

Hair papilla contains blood vessels to nourish hair

Hair color is due to type and amount of melanin

Arrector pili muscle (goosebumps)

Question 18

Function of nails?

Answer 18

Nails: Protective coverings on ends of fingers and toes

Question 19

Three parts of nails?

Answer 19

3 parts of a nail:
Nail plate: overlies nail bed
Nail bed: surface of skin, under nail plate
Lunula: most active growing region; pale, half-moon-shaped region at base of nail plate

Question 20

Another name for sebaceous glands?
What associated with?
What do the produce?
Why is this substance important?
Where are they absent?

Answer 20

Holocrine glands
Usually associated with hair follicles
Produce sebum, which consists of fatty material and cellular debris
Sebum keeps hair and skin soft and waterproof
Excess sebum can result in acne
Absent on palms and soles

Question 21

Another name sweat glands?
Where located?
Where originate?

Answer 21

Also called sudoriferous glands

Widespread in skin

Originate in deeper dermis or hypodermis as ball-shaped coils

Question 22

Two types of sweat glands?
Describe?

Answer 22

Eccrine (merocrine) glands:
most numerous
respond to elevated body temperature

Apocrine sweat glands:
axillary and groin areas
secrete by exocytosis
respond to emotions, pain