chapter 20- blood vessels lecture

innermost layer of the blood vessel, contains the basement membrane and endothelium

where the endothelial cells grow off of

the innermost area surrounding lumen made of simple squamous epithelium

middle layer of the blood vessel containing circular smooth muscle and external elastical lamina

controls vasodilation/vasoconstriction

controls recoiling and expanding of vessels

most external layer, made up of sturdy connective tissue

veins

veins

arteries

large and highly elastic arteries made to withstand the systolic pressure of the heart, like the aorta and the pulmonary trunk

limited elasticity but have a lot of smooth muscle, adapted to constrict or dilate

smallest arteries which are important for blood pressure and blood flow and also always slightly contracted due to vasomotor tone

smallest arteries that bring blood back to the large elastic arteries

single endothelial cell layer making a complete lining and basement membrane with intercellular clefts

endothelial cell layer has pores in it, but the basement membrane is complete. Located in muscular and nervous systems

endothelial cell layer and basement membrane both have pores in them. Located in bone marrow of the bones, liver, and spleen

through postcapillary venules

mostly in the systemic circuit, 55% of blood in the blood in the systemic circuit is in the venous system

large elastic arteries

capillaries

from the arterial blood to tissue

from tissue to the venous blood

diffusion, vesicular transport, bulk flow

movement across the permeable capillary membrane down its concentration gradient. through pores in fenestrated capillaries

some hormones and fatty acids go from blood to the tissues through pinocytosis

movement of large amounts of fluid and dissolved substances through capillary membrane up the concentration gradient

from arterial blood across capillary membrane to surrounding interstitial fluid

from surrounding interstitial fluid back to the blood of the venous end of the capillary

hydrostatic pressure and colloid osmotic pressure

exerted by blood within a capillary, a pushing force. HPb if in the blood, HPif if in the interstitial fluid

created by solutes drawing water towards them via osmosis, a pulling force, COPb if in blood, COPif if in the interstitial fluid

COPif and HPb

COPb and HPif

outward forces exceeding inward forces

inward forces exceeding outward forces

in the arteries by 85%, so the remaining 15% goes to the lymphatic system

blood pressure, resistance, and total blood volume

the measure of force exerted by the moving blood against vessel walls

pressure increases and the vessel expands

pressure decreases and vessel recoils

a pressure gradient for thats needed for circulation

difference between systolic and diastolic BP, measuring the elasticity of vessels so if PP increases arteries must allow for the added pressure

high PP, bradychardia, and irregular breathing; indicates head trauma

the average of both systolic and diastolic pressures, considered to be the perfusion pressure for the body

diastolic pressure + (pulse pressure/3) = MAP

70-110 mmHg, shows adequate tissue perfusion

low MAP= <60 mmHg is inadequate perfusion

high MAP causes edema

40 mmHg (higher for filtration)

20 mmHg (lower to allow for reabsorbtion)

volume of blood returning to the right side of the heart through the systemic circuit, should be equal to CO

skeletal muscle pump, respiratory muscle pump and gravity

during muscle contraction, muscle bellies “milk” blood up to the heart, think of walking and flexing the calf muscle

breathing muscles in the thoracic cavity do the dame function of “milking” blood towards the heart

having elevated feet is the best way to promote venous rate, crossing legs compresses venous return

the amount of friction blood finds flowing through a vessel

1. blood viscosity- the thicker the blood, the more resistance there will be

2. blood vessel length- if the blood vessels are longer, the resistance will increase and BP may increase

   1. blood vessel radius- the blood closest to the walls of the vessels will have more resistance. Vasoconstricted vessels will also have higher resistance than vasodilated vessels

amount of blood moving through vessels in a given period. Dependent on both resistance and pressure gradient

pulse, since it displays the the expansion and recoil of blood vessels

through negative feedback loops

baroreceptors (stretch receptor) and chemoreceptors (chemical sense receptor) are both in the aortic arch, baroreceptors are in coronary sinus and chemoreceptors are in the carotid body

medulla oblongata (cardiovascular center)

cardiac center and vasomotor center

the cardio acceleratory center gets triggered with a high CO, BP, and + inotropic and chronotropic features

the cardioinhibitory center gets triggered with a low BP, CO, and - chronotropic features

under sympathetic control, so causes most vessels to constrict except for those who need blood during fight or flight response like muscles

the heart (alters CO and BP, speeds up contractions), vessels (alters pressure and flow of blood)

with a mini negative feedback loop, if the blood has low oxygen levels and high levels of waste, vasodilation will be triggered so oxygen delivery will increase. when levels regulate then the vessels will stop dilating.