Cardiac histology

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Circulatory system - closed

structure--function

elastic arteries -- conducting , recoil

muscular arteries-- distributing

---smooth muscle here

arterioles-- resistance

metarterioles-- "

capillaries-- exchange

post capillary venues-- "

muscular venues -capacitance

veins-- "

structure blood vessels

tunica intima- innermost

-endothelium -simple squamous epithelium

-very thin

tunic media- middle layer

tunica adventitia - outer layer

elastic

aorta - elastic fibres

-conducting

-recoil after heart beat to maintain blood

- STREAM for hist picture and info

-aorta needs blood supply for nutrient requirement

-blood vessles in t adv

-nerve supply

-loose connective tissue

-fenestrations allow movement of nutrients

muscular

-blood and nerve supply

-many muscle fibres

-50 -70 layerssmooth muscle

-vasoconstrict and vasodialate

arterioles

-two layers int and med

-small blood vessels also

-2-5 layers smooth muscle

metaarteriole

-1-2 smooth muscle layers

microcirculation

-normal - arteriole, meta , capillary , post cap venule

-arterio- venous anastomisis, bypassing exchange surface, straight from artery to vein

-arterial portal system

-venous portal system

Capillaries

-single layer of endothelium lining

-no smooth muscle

-3 types --continuous

basement membrane continuous

--fenestrated

open fenestrae?

--discontinuous

both basement membrane and cells discontinuous

large particles can pass through

Veins

-larger veins have more smooth muscle layers -each layer about same size

-medium sized veins have valves

-venules -

vein artery pic

vein collapsed in samples as blood lost in sampling

slide 16 summary of sorts

distinguishing veins from arteries

-shape

-diameter of vessel compared to thickness of the wall

-blood cells present?

-large peripheral veins often have valves

Lymphatic vessels

-lined with endothelium

-contain valves

-carry lymph

-thin walled

-not clossed

-wbc??

Heart

-3 layers

endocardium -- inner

myocardium --middle

epicardium --outer

deep fibroelastic tisse

recap cardiac muscle cells

heart supported by fibrous skeleton

Slide 26