ANAT W4 key words

circulatory system and integumentary system

tunica intima

inner most lining, flattened epithelial cells supported by connective tissue, capillaries only have this and basement membrane

tunia media

middle layer, contains smooth muscle cells, most variable thickness determining size of lument and therefore differentiates blood vessels

tunica adventitia

outermost connective layer in vessels

large elastic arteries

conducting and maintaining smooth flow of blood with elastic layers

medium musclar arteries

distributing, circular smooth, involuntary muscle fibres, can reguate blood through vasoconstriction

small arteries and arterioles

narrow lumen, thick smooth muscle walls, continuous slight contraction to regulate arterial pressure

pulsatility

arteries are pulsatile and have high blood pressure reflecting systole and diastole

anastomoses

linking between adjacent arteries, providing collateral flow if path is blocked, more often around joints eg. knee

collateral flow

alternate flow of blood in anastomoses

end arteries

arteries with no anastomoses but still drain into capillary veins

venae comitantes

multiple veins wrapped around artery

medium veins

drain venous plexuses, valves, named according to artery

venule and small veins

drain into venous plexuses, no valves, only tunica intima

large veins

wide bundle of longitudinal smooth muscle, well developed tunica adventitia

valves

folds of the endothelium into cusps, preventing backflow of blood, often distal to the entrance of major tributary

capillaries

simple endothelial tubes, number of beds vary according to body region

tone

continuous partial contraction of vacular smooth muscle

visceral motor nerves, specifically vasomotor nerves

nerves that coordinate blood flow through vasoconstriction

vascular venous pumps

a result of venae comitantes, connective tissue around prevents expansion so blood in veins is pumped back

musculovenous pumps

main method of venous return, expansion of msucle pump veins, but consider that they are limited by fascia

thoracic venous pump

double pump system where the heart is connected to the diaphram — SVC on top IVC on the bottom

3 tunics, thinner wall in veins, valves, more numerous than veins, facilitated by smooth muscle contraction (media)

characteristics of the lymphs

lymph nodes

filter to drap particles, defend against foreign antigens, slow flow, cluster where there is high risk of infection

right lymphatic duct of the thoracic duct

2 main ducts of the lymph system

internal jagular joints the subclavian vein

the spot where the lymph drain into the venous system

right jugular trunk, right subclavian trunk, right lymphatic duct

path of the lymph from right head, neck, upper limb, thorax and abdominal

left jugular trunk, left subclavian trunk, thoracic duct

path of the lymph from the rest of the body

epidermis

avascularised outtermost layer of the skin comprised of epithelial cells

dermis

vascularsied, deeper layer of conncetive tissue

hypodermis

subcutaneous layer under the skin

stratum basale

deepest layer of the epithelium, one layer of active stem cells

stratum spinosum

prickly layer, several layer of keratinocytes, the 4th layer from the top

stratum granulosum

granular, 1-5 layers of flattened cells, the 3rd layer from the top

stratum lucidum

clear layer, 2nd layer from the top, not present in thin skin

stratum corneum

superficial layer, mostly dead cells, thickest of the epidermis layers

melanocytes

cells in the basal layer that produce melanin

keratinocytes

cells of the skin

thick skin

hairless, thicker stratum corneum

thin skin

hairy, no stratu lucidum, other strata thinner

papillary layer

1/5 of thickness of dermis, has capillaries and sensory receptors, forms dermal ridges on skin

papillary layer + dermal ridges

layer of dermis + thing that produces the finger and footprints

reticular layer

deeper layer of dermis, attatched to hypodermis, collagen fibre create cleavage/tension lines, has vessles, nerves, hair follicles, sebaceous and sweat glands

reticular layer + cleavage/tension lines

dermis layer + thing that means wound gape

shared mesoderm origin

why is the dermis vascularised but not epidermis

diffusion through interstitial fluid

how does epidermis get nutrients and get rid of waste

subcutaneous tissue

superficial fascia, loose connective tissue of variable thickness under skin

septa

fibrous strands that bind subcutaneous tissue to underlying dense connective tissue especially at palms, soles and scalp

medulla, cortex, cuticle

3 layer of the hair

medulla: not in thinner hair, 2-3 rows of irregular cells

cortex: elongated cells

cuticle: singler layer of thin fat cells

accessory pili muscle

pulling the hair up, sympathetic nervous system

keratinised epidermal cells

what are nails made of

nail plate, nail bed, subungual dermis, periosteum

the chain from nail plate to periosteum that is connected

subungual dermis is thick and highly vascular

lunule

part of the nail where new nail cells are developing, pooly vascularised

sebaceous glands

connected to hair follicles, produces sebaceous substances

sweat glands

release sweat into hair follicles or skin via pores

ceruminous glands

modified sweat glands that produce ear wax

dermatome

the area of the skin supplised by one spinal cord nerve, due to segmental innervation. due to somites dragging skin with it as it develops into organ buds

referred pain

somatic area supplied by the same dermatome as the deeper organs

stretch marks

lateral bonding between collagen fibres is broken andd breaks small blood vessels

burn epidermis only

1st degree burn

burn epidermis and 1st layer of dermis

2nd degree burn

burn the full thickness of the skin

3rd degree burn

due to catastrophic loss of body fluids

why do burns result in death?