Veins vs Arteries Flashcards
Which has a larger lumen, veins or arteries?
veins (larger diameter)
list the layers of a blood vessel (BV) from the most inner part to outer part
lumen, endothelium/simple squamous/epithelia, CT, smooth muscle ((SM) and sympathetic division of ANS)
where does vasocontractility happen in BVs?
in the smooth muscle tissues
What tissue/s in BVs and other organs are controlled by the sympathetic ANS
smooth muscle tissue
which blood vessels are most numerous and the smallest in diameter and thinnest?
capillaries
What blood vessels allow gas, nutrients, waste, and hormones to diffuse and into the blood?
capillaries/ capillary beds
what type of tissue/ cells are the capillaries made from that allow gas, nutrients, waste, and hormones to diffuse?
endothelium/ simple squamous
what is the ring located outside of a capillary?
pre- capillary sphincter (P.C.S.)
* a band/ring of smooth muscle*
Does auto-regulation happen locally or on a large scale?
locally
ex: at the pinky finger
If O2 is low then…
CO2 is high ( low PH/ more acidic)
What systems are not used by auto-regulation?
never uses nervous or endocrine system
In auto-regulation where chemoreceptors located?
in the plasma membrane (PM)of smooth muscle cells of pre-capillary sphincter (P.C.S.)
What doe chemoreceptors do?
detect local changes (PH, O2, CO2, etc..)
ex: ↓ Ca2+ (low Ca2+)
With less Ca2+ thus less contractility, what happens to the size of the pre-capillary sphincter?
less contractility means it will dilate/ open more/ widen
What vessels have the most elastin compared to veins?
arteries ( higher blood pressure (BP)compared to veins)
What are the effects of the pre-capillary sphincter dilating/ widening
- blood flow goes⬆️ into local capillary
- PH goes⬆️( more alkaline), gas exchange goes⬆️, local O2 goes⬆️, and CO2 goes⬇️
What effect does the amount of Ca2+ have on contractility
the more Ca2+ the more contraction/ contractility: less Ca2+ is less contractions/ contractility
List the pressure from least to greatest for veins, venules, and capillaries
⬇️⬇️⬇️veins, venules⬇️⬇️, capillaries⬇️
(pressure stays relatively constant regardless of V. systole and V. diastole)
What blood vessels deal with larger pressure differences during V. systole and V. diastole?
arteries (⬆️elastin in CT)/(protein fiber)
What is another name for auto-regulation
intrinsic regulation ( a way to get local parameter back into homeostatic range)
- NEVER uses nervous system(NS) nor endocrine system
Intrinsic regulation/ auto-regulation
local fixes, happens in organs and tissues of the body (smooth muscle)
Extrinsic regulation
happens in cardiac muscle, controls regulate heart rate, myocardial contractility, and vascular smooth muscle to maintain cardiac output, blood flow distribution, and arterial blood pressure.
Name two way blood get back to the atria of the heart from veins ( venous system)
due to no/ low pressure difference
- vein valves
( compartmentalized blood creating high blood pressure to the next compartment
ex: foot( valve pushes blood up) to calf (valve) pushes blood up to upper leg
- Skeletal muscle tone ( background contractions)
helps with body temp, posture, keeps joint and bones in place, squeezes veins (background/resting contractions)(⬆️pressure in veins)
What two conditions are related to faulty vein valves?
- varicose veins ( protrusion of the veins due to blood pulling possibly clots
- hemorrhoids
The greater the pressure difference allows for what?
blood to get back to the heart
What similarities do the semilunar valves have with vein valves?
They pop open due to pressure difference
What can be the damaging effects of blood pooling?
blood clotting
