integamentry system

Question 1

layers of the skin

Answer 1

epidermis

dermis

hypodermis

Question 2

epidermis

Answer 2

outermost layer

made of many layers of tightly packed epithilial cells

keratnised, stratified, squamous epithilium
avascular
mitosis occurs

Question 3

dermis

Answer 3

middle layer
dense irregular ct layer with collagen fibres- tensile strength

a dense connective tissue
with good blood supply
sensory receptors
hair follicles grow from hear
sweet and oil glands are here

Question 4

hypodermis

Answer 4

lowest layer
adipose tissue, areolar connective tissue to store lipids

insulation

Question 5

epidermal cells

Answer 5

90 percent are keratincytes
tough protein
protection
lamellar granules= water proof and prevent microbes entering making it intact skin

melanocytes= produce skin pigments protect DNA from uv damage

Question 6

as cells dies in epirderimis

Answer 6

they flattern and move towards the top

Question 7

dermis cells

Answer 7

fibroblast- cells produce connective tissue// secrete background matrx

phagocytes in this cell- macrophage

adipose tissue- store lipids

Question 8

functions of integamentry system

Answer 8

REGULATES BODY TEMPERATURE:
vasodilation, insulation, piloerection of hair

STORAGE:
lipids// blood in capilaries

DETECTS SENSATION:
thermoreceptors, mechanoreceptors ( touch ), nociceptors (pain receptors)

PROTECTION:
abrasion ( intact skin ), melanocytes protect against UV

SYNTEHSIS OF V D3

EXCRETES AND ABSORB
ex- salt, water, oil, sweet for lub

ab- medication lipid soluble

Question 9

syntehsis of VD3

Answer 9

Synthesis of vitamin D3 by UV light – activated to calcitriol by liver enzymes for multiple body functions e.g. absorption of calcium and phosphorous from the GIT and protection against cancer development.

Question 10

accessory structures

Answer 10

hair

nails

sweet glands

sebacous glands

haemaglobin pigmentation

Question 11

hair

Answer 11

non living made from proteins

keratin

Contraction of arrector pili muscles (autonomic) – hairs upright (causing goose bumps).
protection UV// entering of pathogens

Question 12

NAILS

Answer 12

keratinised cells
Protects exposed/distal tips of digits.
Helps digit withstand distortion/counter pressure when subjected to mechanical stress.
Allows manipulation and grip of small objects.
Allows scratching and grooming of the body.

Question 13

sweet glands

Answer 13

apocrine
Activated at puberty.
Secrete sweat into hair follicles; odour since bacteria use it for nutrition.

merocrine:
secrete straight to skin
Cools skin surface to reduce body temperature; excrete water, electrolytes and some drug metabolites; dilutes harmful chemicals on skin; discourages microbial growth by flushing off skin or via dermcidin.

Question 14

sebacous glands

Answer 14

Inhibits bacterial growth; lubricates and protects keratin of the hair shaft.

Question 15

skin colour

Answer 15

Melanin: brown, yellow-brown to black; protects against UV damage.
Carotene: orange-yellow; stored in epidermis; also stored in fat/adipose cells; can be converted to Vitamin A, needed by the retina.

Question 16

nociceptors

Answer 16

pain
Respond to extremes of temperature, dissolved chemicals including those released by damaged cells, physical damage, infection, inflammation, ischaemia.

Question 17

thermoreceptors

Answer 17

Free nerve endings in dermis

Question 18

mechanorecptors

Answer 18

Free nerve endings sensitive to touch & pressure between epidermal cells.
Hairs: nerve endings of root hair plexus.
Merkel cells/Tactile discs: extremely sensitive fine touch & pressure receptors in basal layer of epidermis, with very small receptive fields.
Tactile corpuscles in dermis reticular layer; detect fine touch & pressure.
Lamellated corpuscles: deep pressure and pulse vibration receptors.
Ruffini corpuscles: dendrites intertwined with collagen fibres detect distortion and excess stretch in the dermis and hypodermis.

Question 19

age effects

Answer 19

epidermis things= increased risk of skin tear, infection and injury.

Dendritic/Langerhans cell number drops= increase skin infection

Vitamin D3 production drops = increase risk of fracture osteomalasis- soft bones

Gland secretion drops – dry, possibly scaly skin and decreased sweat production – reduction in heat loss ability.\

Hair follicles reduce function – finer, thinner hairs. Due to drop in melanocyte function, hairs turn grey/white.

Question 20

merkel cells

Answer 20

Detects fine touch and is located in the epidermi

Question 21

ruffini corpsals

Answer 21

Detects tension and distortion of the dermis

Question 22

tactile corpsules

Answer 22

Located in dermal papillae it detects low frequency vibration, light touch and pressure