Chapter 12(mammalian Skin)

Question 1

What is skin?

Answer 1

The outer body covering of vertebrates (animals with backbones).

Question 2

Functions of skin:

Answer 2

1. Protection
2. Temperature regulation
3. Sensation
4. Excretion

Question 3

The skins the largest organ with a weight of

Answer 3

4.5-5kg

Question 4

What are the layers of the skin ?

Answer 4

the epidermis and the dermis.

Question 5

What is the upper or outer layer of the skin.

Answer 5

Epidermis

Question 6

_____ is a tough, waterproof, protective layer

Answer 6

The epidermis

Question 7

What provides the skin with strength and elasticity ?

Answer 7

Dermis

Question 8

What is the thin layer anchoring the epidermis and dermis?

Answer 8

Basement membrane

Question 9

The basement membrane is made up of

Answer 9

a series of elaborately interconnecting molecules that act as ropes and grappling hooks to hold the skin together.

Question 10

The subcutaneous layer is composed of

Answer 10

protein fibres and adipose tissue (fat).

Question 11

What Make up 90% of the epidermis?

Answer 11

Keratinocytes

Question 12

Keratinocytes Produce;

Answer 12

keratin, a tough protein that protects the skin

Question 13

______ Produce melanin, the pigment that gives skin its color

Answer 13

Melanocytes

Question 14

What Protect the DNA of keratinocytes from sun damage?

Answer 14

melanosomes

Question 15

packets of melanin are called

Answer 15

melanosomes

Question 16

Difference in skin tone is because of the

Answer 16

variations in melanin production and distribution.

Question 17

melanin sometimes accumulates in patches, forming ____

Answer 17

freckles, age spots, or liver spots.

Question 18

what makes redheaded people more sensitive to the sun?

Answer 18

pheomelanin

Question 19

What is albinism,

Answer 19

A total lack of melanin, a genetic condition

Question 20

The epidermis is composed of what cells?

Answer 20

Keratinocytes
Melanocytes
Langerhans cells
Merkel cells:

Question 21

What are the Langerhans cells of the skin?

Answer 21

Part of the immune system, recognize and fight off harmful substances.

Question 22

Where are langerhans cell produced

Answer 22

Bone marrow

Question 23

What is merkel cell of the epidermis?

Answer 23

Touch receptors located in sensitive areas like fingertips.

Question 24

Where does Strength, Sensation, and Temperature Regulation Meet?

Answer 24

Dermis

Question 25

the dermis or lower layer of the skin is richly supplied with

Answer 25

blood vessels and sensory nerve endings.

Question 26

The dermis is composed of

Answer 26

Primarily made of collagen and elastin fibers, with fewer cells compared to the epidermis.

Question 27

The main structural component of the dermis is a protein called_____

Answer 27

collagen

Question 28

Bundles of collagen molecules pack together throughout the dermis, accounting for ______ of the dry weight of skin.

Answer 28

three-fourth

Question 29

Collagen is responsible for

Answer 29

The skin’s strength

Question 30

Elastin is responsible for

Answer 30

The skin’s elasticity

Question 31

What are the Cells that produce collagen and elastin.

Answer 31

Fibroblast

Question 32

What are the layer of the dermis

Answer 32

Contains two layers: the papillary layer (upper) and the reticular layer (lower).

Question 33

the reticular layer. It is made primarily of

Answer 33

coarse collagen and elastic fibres.

Question 34

glands and hair follicles are often anchored in

Answer 34

the reticular layer of the dermis.

Question 35

_____ contains several different types of sensory receptors

Answer 35

The reticular layer

Question 36

_____ are receptors found in the deep dermis of weight-bearing surfaces,

Answer 36

Pacinian corpuscles

Question 37

What are skin appendages?

Answer 37

Structures like hair, nails, and glands embedded within the skin.

Question 38

Scalp hair grows at about

Answer 38

1mm every 3 days.

Question 39

the visible part of the hair is called

Answer 39

shaft

Question 40

Where does hairs grow from ?

Answer 40

Grows from follicles, with the bulb at the base nourishing it.

Question 41

Hair is composed primarily of.

Answer 41

keratin

Question 42

At the base of the follicle is the bulb, which contains

Answer 42

cells that give rise to the keratinocytes that make up the hair, as well as blood vessels that nourish the growing hair.

Question 43

The colour of hair is due to____,

Answer 43

melanin

Question 44

Dark hair contains

Answer 44

true melanin

Question 45

blond and red hair result from?

Answer 45

types of melanin that contain sulphur and iron

Question 46

Hair goes grey when ___

Answer 46

melanocytes age and lose the enzyme necessary to produce melanin.

Question 47

White hair occurs when

Answer 47

air bubbles become incorporated into the growing hair.

Question 48

The texture of hair results from

Answer 48

the shape of the hair shaft.

Question 49

Straight hair appears ____ in cross section,

Answer 49

round

Question 50

wavy hair has an ____ in cross section,

Answer 50

oval shape

Question 51

curly hair has _____ appearance.

Answer 51

An elliptical or kidney-shaped

Question 52

Function of the finger mail

Answer 52

1. Protect fingertips and toes from injury. 2. Aid in grasping small objects. 3. Enable scratching.

Question 53

Nails on the fingers and toes are made of

Answer 53

hard, keratin-filled epidermal cells.

Question 54

The part of the nail that is visible is called

Answer 54

the nail body,

Question 55

the portion of the nail body that extends past the end of the digit is called

Answer 55

the free edge.

Question 56

White, crescent-shaped area at the base, lacking blood vessels and covered by thicker epidermis is called

Answer 56

Lunula

Question 57

The part of the nail buried under the skin

Answer 57

Mail root

Question 58

where are the nail cells are produced.

Answer 58

The nail root

Question 59

Fingernails typically grow _____ per week.

Answer 59

1 mm (0.04 in)

Question 60

What is the Eccrine sweat gland?

Answer 60

Most numerous, found almost everywhere (especially palms and soles).

Question 61

_______ sweat gland Secrete watery sweat for cooling and waste removal.

Answer 61

Eccrine

Question 62

_______ sweat gland secrete milky fluid potentially involved in sexual attraction.

Answer 62

What are apocrine

Question 63

Sebaceous glands are found

Answer 63

all over the body except on the palms, the soles, and the top of the feet.

Question 64

Sebaceous produce an oily substance called,

Answer 64

sebum

Question 65

Function of the sebum

Answer 65

keeps the Skin and hair from drying out and inhibits the growth of certain harmful bacteria.

Question 66

_____ are modified sweat glands found in the ears

Answer 66

ceruminous, glands

Question 67

The ceruminous gland secrete

Answer 67

a waxy substance that helps prevent foreign particles from entering the ear.