A 3 Integumentary

Question 1

what are the 3 layers of the skin?

Answer 1

epidermis, dermis, hypodermis

Question 2

which of the three layers of the skin provides the support and elasticity of the skin?

Answer 2

Reticular dermis

Question 3

which layer of the skin contains immune cells that act as a defense of foreign invaders through skin?

Answer 3

the dermis generally contain these cells and they are called langerhans cells.

Question 4

what is another name for the hypodermis?

Answer 4

subcutaneous connective tissue.

Question 5

what are the layers of the skin from superficial to deep?

Answer 5

corneum, lucidum (only where skin is thick), granulosum, spinosum, and basale.

Question 6

what is a keratinocyte?

Answer 6

cells of the epidermis that produce keratin an intermediate filament. Note that about 70% of the cells in the epidermis are keratinocytes.

Question 7

what is another name for the keratin intermediate filaments?

Answer 7

tonofilaments

Question 8

when tonofilaments agregate, what do they become?

Answer 8

tonofibrils

Question 9

keratin always exists as:

1) singles
2) pairs
3) triplets

Answer 9

pairs of one acidic and one basic

Question 10

what types of keratin are located in the stratum basale?

Answer 10

keratin types 5 &14. (these types are those found deeper)

Question 11

what types of keratin are located in the stratum spinosum & more superficial layers?

Answer 11

keratin types 1 &10

Question 12

which cell layer is mitotically active?

Answer 12

stratum basale

Question 13

what causes the spinous cells of the epidermis to be spiny?

Answer 13

the desmosomes cause this.

Question 14

what makes up the cytoplasmic plaques in desmosomes?

Answer 14

plakoglobin and desmoplakin

Question 15

What is the glycoprotein that connect the two plaques in desmosomes called?

Answer 15

cadherins

Question 16

what are the two types of cadherins called?

Answer 16

desmogleins and desmocollins.

Question 17

what is keratinization?

Answer 17

the progressive maturation of keratinocytes characterized by the accumulation of keratin.

Question 18

the stratum granulosum is how many layers thick?

Answer 18

1-3 cells thick normally and up to 10 in palms and soles of feet.

Question 19

in the epidermis, where does the cell normally die?

Answer 19

Normally in the stratum granulosum as these cells release lysosomal enzymes that destroy the nucleus and organelles. (furthers the process of keratinization) note: A few cell may even die in the stratum corneum.

Question 20

what is a keratohyaline granule?

Answer 20

non membrane bound granules that contain proteins and lipids used for form filaggrin and the marginal band.

Question 21

what is filaggrin?

Answer 21

a cement like substance that holds keratin filaments together.

Question 22

what is the marginal band?

Answer 22

the inner lining of the horny (cornified) cells.

Question 23

where will you find stratum lucidum?

Answer 23

in the areas of your body with thick skin such as feet and hands.

Question 24

what major function does the stratum corneum play?

Answer 24

creates a barrier for micororganisms, water loss, physical protection, uv absorption, etc.

Question 25

which cell layer has a lot of keratohyaline granules

Answer 25

stratum granulosum.

Question 26

which layers make up the basal lamina?

Answer 26

lamina lucida and lamina densa

Question 27

which layers make up the basement membrane?

Answer 27

the lamina lucida, lamina densa, and the lamina reticularis

Question 28

which type of collagen is largely found in the lamina densa?

Answer 28

type 4 collagen

Question 29

which 4 things make up the basement membrane ZONE?

Answer 29

plasma membrane, lamina lucida, lamina densa, and sub basal lamina.

Question 30

what is the plaque of a hemidesmosome composed of?

Answer 30

bullous pemphigoid antigen (BP1, BP230) NOTE: desmosomal plaques are made of plakoglobin and desmoplakin!

Question 31

the majority of the cells in the dermis are?

Answer 31

fibroblasts

Question 32

fibroblast secrete what?

Answer 32

collagen, elastin, and ground substance

Question 33

what percentage of the skins weight is collagen?

Answer 33

75%

Question 34

what are the two divisions of the dermis?

Answer 34

papillary dermis and reticular dermis

Question 35

what type of collagen predominates in the papillary dermis layer?

Answer 35

type 3 collagen and it is considered a loose connective tissue

Question 36

what are meissners corpuscles?

Answer 36

nerve endings that are sensitive to touch that are located in the papillary dermis layer.

Question 37

what is the dermal papillae?

Answer 37

the area of the dermis (papillary dermis) that the vasculature is located which regulates thermoregulation.

Question 38

what type of collagen predominates in the reticular dermis?

Answer 38

type 1 collagen. It is considered a dense and irregular connective tissue.

Question 39

T/F | autonomic nerves innervate all glands.

Answer 39

false, sebaceous glands. They are controlled hormonally.

Question 40

what is the function of Vater-Pacine corpuscles?

Answer 40

they are large nerve endings that mediate the sense of PRESSURE

Question 41

what do melanocytes produce?

Answer 41

melanin

Question 42

what makes skin black or white?

Answer 42

the differences are based off of the melanocytes. 1) Stage that its in (1-4) 2) Melanosome size 3) The number of melanosomes 4) How melanosomes are grouped 5) How quickly melanosomes are degraded.

Question 43

what effect does UV light have on langerhans cells?

Answer 43

their numbers are decreased because it can kill them

Question 44

where are sebaceous glands found?

Answer 44

everywhere but palms and soles of feet.

Question 45

what type of gland is a sebaceous gland?

Answer 45

a holocrine gland

Question 46

where do you generally find apocrine glands?

Answer 46

axilla, genital region, areola, eyelid.

Question 47

what is decapitation secretion?

Answer 47

APOCRINE gland secretion

Question 48

what controls apocrine glands

Answer 48

they are controlled by adrenergic sympathetic innervation

Question 49

what is another way to say eccrine gland?

Answer 49

merocrine gland.

Question 50

sweat glands are classified as which types of glands?

Answer 50

eccrine glands.

Question 51

what do "clear cells" secrete?

Answer 51

aqueous material and glycogen

Question 52

what do "dark cells" secrete?

Answer 52

sialomucin

Question 53

the myoepithelial cells that surround the eccrine glands are controled by?

Answer 53

cholinergic stimuli (acetylcholine through parasympathetics)

Question 54

what is the hair follicle and sebaceous gland collectively called?

Answer 54

pilosebaceous unit

Question 55

what causes hair pigmentation?

Answer 55

melanocytes

Question 56

what is the average rate of hair growth?

Answer 56

1cm/month

Question 57

what are the 3 cycles of hair growth?

Answer 57

1 Anagen (active growth phase 89%) 2) Catagen (growth arresting phase 1%) 3) Telogen (resting phase with fallout 10%)

Question 58

where does the nail plate arise?

Answer 58

from the matrix

Question 59

what is the hyponychium?

Answer 59

the skin underlying the free end of the finger nail