integumentary system and somatosensation

Question 1

subcutaneous

Answer 1

this is fatty layer deep to the epidermis and dermis

-protects underlying structure, stores energy, and is insulation for the body

Question 2

8 functions of the integument

Answer 2

• protection (physical, chemical, UV)
• water regulation
• temperature regulation
• vitamin d synthesis
• sensory perception
• excretion by sercretion
• storage of blood (5% of total)
• non-verbal communication (Janice, cyanosis, really pale, moist, flushed –> can give alot of info about what may be happening in the body)

Question 3

epidermis

Answer 3

• this is the most superficial layer
• avascular
• made of stratified squamous epithelium
• has five layers (four at thin skin)

Question 4

stratum basale

Answer 4

• deepest layer of the epidermis
• attachment to basal lamina
• stem cells, melanocytes, and merkel cells
• cell division occurs
• just a single layer of cells thick

Question 5

stratum spinosum

Answer 5

superficial to just the basale layer and deep to every other layer

• cells at this layer are healthy and living because they have a nucleus
• some cell division occurs
• langerhans cells and melanocytes are present

Question 6

stratum granulosum

Answer 6

• this is directly superficial to the spinosum
• some cells still living
• keritinocytes produce keratonyalin and keratin
• water proofing occurs at this layer when cells release a lipid rich substance that coats the cells

Question 7

what is ironic about the lipid rich protective coat that is secreted

Answer 7

it blocks cells from getting nutrients and releasing waste so ultimately leads to cell death

Question 8

stratum lucidum

Answer 8

• this is only present in thick skin

- appears glossy and is at the palms and soles of feet

Question 9

stratum corneum

Answer 9

• most superficial layer
• contains multiple layers of flattened dead, interlocking keratinocytes
• typically relatively dry
• permits slow water loss by insensible perspiration

Question 10

four cell types of the epidermis

Answer 10

• keratinocytes
• melanocytes
• tactile cells (merkel cells)
• dendritic cells (langerhans cells)

Question 11

keratinocytes

Answer 11

• protection physical and mechanical
• waterproof the skin
• vitamin D synthesis
• production of antibiotics and enzymes to detoxify skin
• joined by desmosomes

Question 12

melanocytes

Answer 12

• produce melanin
• absorption of UV light
• transfer melanin to keratinocytes via cell processes

Question 13

what is skin color determined by

Answer 13

skin color is not determined by the number of melanocytes but the amount of melanin produced. most humans have the same amount of melanocytes

Question 14

melanin

Answer 14

-helps to protect from the sun and absorbs UV

Question 15

tactile epithelial cells

Answer 15

-these are receptors to touch

Question 16

dendritic cells

Answer 16

• part of the immune system

- take up foreign proteins bia endocytosis and transports them to the lymph nodes to begin an immune response

Question 17

what structures are derived from the epidermis

Answer 17

• nails
• sweat glands
• hair

Question 18

sweat glands

Answer 18

• these can be apocrine or eccrine

- these are widely distributed throughout the skin

Question 19

eccrine sweat glands

Answer 19

-they are important for thermoregulation and widely distributed throughout the skin

Question 20

apocrine sweat glands

Answer 20

• these are in special places like the arm pit, groin, nipples
• ceruminous glands: these secrete ear wax
• mammary glands: these secrete milk
• others secrete smells and oils etc

Question 21

dermis

Answer 21

-highly vascularized, neurological structures within, sweat glands, hair follicles, and hair glands within

Question 22

arrestor pili muscles

Answer 22

these attach to hair roots and cause hairs to stand during certain situations

Question 23

vascular functions of the dermis

Answer 23

• supplys dermis
• supplys nutrients to avascular epidermis
• important in controlling body temp

Question 24

nerve fiber functions of the dermis

Answer 24

• tactile (touch) receptors
• control blood flow
• control glandular secretion

Question 25

papillary layer

Answer 25

this layer has rolling ridges to increase the surface area that it has in contact with the epidermal region superficial to it - made of loose connective tissue

Question 26

dermal papillae:

Answer 26

- nipple like projections that give this layer its name | - they increase surface area and allow for gas exchange, waste etc.

Question 27

why is it important to increase the surface area between the epidermis and the papillary layer

Answer 27

this is because the epidermis has not blood supply so it must rely on diffusion for nutrients and this kinda explains why the more superficial layers are dying/dead cells because the nutrients cannot make it to them

Question 28

friction ridge

Answer 28

- folds of epidermis and dermis on fingers, palms, soles, and toes - these increase friction to help with grasping things

Question 29

reticular layer

Answer 29

- this makes up the majority of the dermis | - made of dense irregular connective tissue with bundles of collagen fibers

Question 30

cleavage lines

Answer 30

these are the collagen and elastin fibers organized in thin parallel bundles to resist stresses -when the skin is stretched too much the fibers tear and form striae (stretch marks)

Question 31

why is it important to try to make incisions along/parallel to the cleavage lines

Answer 31

this allows for a better healing process and less of a scar

Question 32

skin changes with aging

Answer 32

- thinner skin - decreased dendritic cells - decreased vit D3 production - decreased melanocyte activity - dryer skin

Question 33

exteroceptors

Answer 33

- found in the skin or mucous membranes | - these are the sensory receptors in the skin

Question 34

types of skin receptors

Answer 34

``` non encapsulated tactile receptors - free nerve endings -tactile (merkel) disc -root hair plexus encapsulated tactile receptors -tactile corpuscles -lamellated corpuscles -bulbous corpuscles ```

Question 35

free nerve endings

Answer 35

- pain and temperature | - found in the papillary layer of the dermis and deep epidermis

Question 36

tactile disc

Answer 36

associated with tactile cells in the stratum basale of epidermis -light touch

Question 37

root hair plexus

Answer 37

- movement of hairs- light touch | - surround hair follicles in dermis

Question 38

tactile corpuscles

Answer 38

- in tips of some dermal papillae | - light touch

Question 39

lamellated corpuscles

Answer 39

- in the dermis, subcutaneous tissue, and some vicera | - deep pressure sensation

Question 40

bulbous corpuscles

Answer 40

- in the dermis and subcutaneous | - deep pressure

Question 41

what receptors are in the dorsal column medial lemniscus pathway

Answer 41

- tactile (merkle) disc - tactile corpuscles - root hair plexuses

Question 42

what receptors are used in the anterolateral pathway

Answer 42

- bulbous coupuscles | - free nerve endings

Question 43

receptive fields

Answer 43

- the sensory receptors that feed into a sensory neuron

Question 44

small receptive fields have what

Answer 44

- good discriminatory touch to determine where something is affecting you - this is important in your fingers, eyes, etc

Question 45

big receptive fields have what

Answer 45

they have bad discrimminatory touch

Question 46

dermatomes

Answer 46

area of the skin innervated by a single spinal nerve | -circumferential in the trunk and distorted in the limbs

Question 47

shingles

Answer 47

- this is the reactivation of the chicken pox | - the virus travels down the sensory axons to the dermatome