Histology - Integument

Question 1

where are the nerves and blood vessels located in the integument (generally)? why?

Answer 1

in the inner layers

don’t want them punching through the skin to disrupt water proofing

don’t want foreign substances to get into blood

Question 2

what are the 6 layers of the epidermis?

Answer 2

1. stratum corneum
2. stratum lucidum
3. stratum granulosome
4. stratum spinosum
5. stratum basale
6. basement membrane

Question 3

what layer of the epidermis is this? how can you tell?

Answer 3

stratum spinosum

there are “spines” joining the cells (actually desmosomes)

Question 4

label the parts of the epidermis

Answer 4

A: stratum corneum

B: statum lucidum

C: stratum granulosum

D: stratum spinosum

E: stratum basale

Question 5

what layer of the epithelium is this? how can you tell?

Answer 5

stratum granulosum

filled with dark granules

Question 6

what do the granules in the stratum granulosum do?

Answer 6

provide a mechanical barrier

Question 7

what happens to the cells in the stratum granulosum as they move towards the outside of the body?

Answer 7

they become more squamous in shape because they are becoming dead

Question 8

why does the stratum lucidum appear transluscent on slides?

Answer 8

the nuclei are lost

Question 9

why doesn’t it hurt when skin cells slough off the body? what layer of the epidermis is this?

Answer 9

they are dead

stratum corneum

Question 10

what are the functions of the stratum cornuem?

Answer 10

waterproofing and mechanical protection

Question 11

what is an epidermal peg?

Answer 11

the epidermis extends into the dermis

Question 12

what is a dermal papilla?

Answer 12

the dermis extends into the epidermis

Question 13

what is the function of dermal papillae and epidermal pegs?

Answer 13

to provide more SA for attachment

Question 14

label this image

Answer 14

A: epidermal peg

B: dermal papilla

Question 15

what are the layers of the skin from outer to inner?

Answer 15

epidermis, dermis, hypodermis

Question 16

what is the primary cell type of the epidermis?

Answer 16

keratinocyte

Question 17

what are cytokeratins?

Answer 17

a family of fibrous proteins that polymerize as intermediate filaments

Question 18

what do keratinocytes contain an abundance of?

Answer 18

cytokeratins

Question 19

what does cornification of the epidermis achieve?

Answer 19

makes a physical barrier

Question 20

how does the epidermis form the protective outer layer?

Answer 20

progressive proliferation and cornification

Question 21

what is cornification?

Answer 21

broad term signifying all processes involved in the formation of the horny layer of the epidermis, including the consolidation of the intracellular, lipid-rich “glue”

Question 22

what is keratinization?

Answer 22

series of programmed events whereby keratinocytes in the basal layer of the epidermis mature, polymerization of cytokeratin, and undergo apoptosis producing the stratum corneum

Question 23

what is apoptosis? where do you find this in the integument?

Answer 23

the death of cells in normal body function.

the epidermis

Question 24

what determines the thickness of the epidermis?

Answer 24

the rate of cell division in the stratum basale

Question 25

what are the accessory cells found in the epidermis?

Answer 25

melanocytes, Merkel cells, Langerhans cells

Question 26

what are melanocytes? where are they found?

Answer 26

pigment cells that contain melanosomes stratum basale

Question 27

what are Merkel cells and where can you find them?

Answer 27

somatosensory end organs stratum basale

Question 28

what are Langerhans cells and where can you find them?

Answer 28

monocyte-derived dentritic cells. they do immunosurveillance stratum spinosum

Question 29

what is the dermis made out of?

Answer 29

dermal fibroblasts/fibrocytes arector pili axons adipocytes

Question 30

what is the main cell type found in the dermis?

Answer 30

dermal fibroblasts/fibrocytes

Question 31

what is a myocyte?

Answer 31

the smallest unit of muscle tissue

Question 32

what is the function of arrector pili? what type of muscle are they made of?

Answer 32

to make hairs stand on end. smooth muscle

Question 33

what are adipocytes?

Answer 33

fat-storing cells

Question 34

what is the hypodermis made of?

Answer 34

adipocytes, skeletal muscle myocytes, fibrocytes

Question 35

what are appendages as they relate to the integument?

Answer 35

things that grow out of the epidermis + dermis

Question 36

what are the types of glands found in the integument?

Answer 36

sweat, sebaceous, anal, uropygial

Question 37

what is a hair follicle?

Answer 37

invagination of the epidermis that holds the hair bulb/root

Question 38

what shape are the cells in the stratum basale?

Answer 38

cuboidal

Question 39

what occurs in the stratum basale?

Answer 39

mitosis --\> cell creation

Question 40

what are the granules in the stratum granulosum?

Answer 40

keratin

Question 41

what are the fibers in the dermis made of?

Answer 41

collagen

Question 42

glands are follicles are products of which layer of the integument?

Answer 42

epidermis

Question 43

how are the fibers laid down in the dermis?

Answer 43

in a matrix

Question 44

generally speaking, is the epidermis or dermis stronger?

Answer 44

dermis