Blood Vessels Flashcards
Artery
from vessel unit - a little more detail
vessel that takes blood away from the heart
-typical takes oxygenated blood (minus pulmonary arteries and ambilical artereis)
Vein
from vessel unit - a little more detail
vessels that take blood to the heart
-typically deoxygenated blood (minus pulmonary veins and amilical veins)
-has valves to stop back flow
Capillaries
tiny blood vessesl that serve as site of gas exchange
tunica intama
Tunics of vessles
-endothelium
-inner lying of all vessels
needs to be smooth - once it is damaged it and can lead to atherosclerosis (causes a numder of disease)
tunica media
-middle layer of vessels (NOT IN CAPILLARIES)
-made of smooth muscle (makes it involuntary)
-thicker in arteries because they are pressurized
tunica externa
-outer most layer
-made of collogen
-if collogen breaks down it can cause an aneurysm
Neural BP Response
-short term
-baroreceptors in carotid sinus & aortic arch senses when the blood pressure in your heart changes
-communicate w/ cardio centers in medulla oblongata of brainstem to try and control pressure and make the heart beat faster or slower (usues nerve fibers of the heart or the vagus nerve)
Hormonal BP
short term
-epinephrine and norepinephrine
-causes cardiac output to increase which increases blood flow and blood pressure
Hormonal BP
long term
-ADH causes kidneys to retain fluid, which causes a rise in fluid volume and therefore a rise in bp (if consentrated in the body ADH is a vasopressin - causes vessels to constrict and raise BP)
-Atrial natriuretic peptide (hormone) has the opposite effect of aldosterone. Causes the body to inhibit aldosterone and instead causes sodium to be removed by kidneys through the urine, which decreases fluid and therefore BP
-renin-angiotensin-aldosterone system. Eventually angiotensin 2 increases blood pressure by causing the sympathetic nervous system to release catacholmines, increasing ADH and aldosterone secreation. Also angiotensisn 2 is also a vasoconstritor itself
Renal BP
long term
-long term
-Kidneys can increase and decrease fluid which had a direct relationship with BP
-kidneys produce Renin which is a big part of the Renin- angiotensin - aldosterone system
Renin-Angiotensin-Aldosterone System
Renin ismade in the juxtaglomerulary apparatus of the kidneys and converts angiotesinogen into angiotensin 1. then with ACE (angiotensin converting enzyme) converts angiotensin 1 into angiotensin 2. This then increases blood pressure by causing the sympathetic nervous system to release catacholmines and increases ADH secreation, and finally increase aldosterone secretion. But angiotensisn 2 is also a vasoconstritor itself
Starling’s Law of Capillaries
starting in the artieral end of the capillary bed, hydrostatic pressure is pushing fluid out of the capillary and into interstitial fluid (determined by BP). This brings nurtients and other things into cells. However fluid needs to be broguht back into capillaries on venous side. This is done with osmotic/oncotic pressure. Solutes (sodium, albumin(this is where oncotic pressure comes in)) are in the venous side of capillaries and are drawing fluid in from the interstitial space/fluid.
blood hydrostatic pressure
-pressure that forces fluid out of arterial end of capillary and INTO interstitial fluid
-determined by blood pressure
blood osmotic/oncotic pressure
-pressure that draws fluid back into venous end of capillaries FROM interstitial fluid
-determined by solutes in blood stream, notably albumin (oncotic)
