Arteries & Veins
The 4 types of arteries.
What are conducting arteries, distributing arteries, resistance arteries, and metarterioles (arterioles).
The purpose of capillaries.
What is the location of gas, nutrient, waste, and hormone exchange between blood and tissues.
The definition of blood flow.
What is the amount of blood flowing through an organ, tissue, or blood vessel at a given time.
Explain an aneurysm
The weak part in an artery or heart wall which bursts. Can cause a hemorrhage. Results from congenital weakness of blood vessels, or bacterial infections.
What are the three layers of veins and arteries (from outside to inside)
Tunica externa -- connective tissue
Tunica media -- smooth muscle, collagen, elastic tissue
Tunica interna -- simple squamous
The purpose of metarterioles.
What is the linking of arterioles directly to venules in order to bypass capillary beds.
The capillary that occurs in most tissue, has tight junctions and pericytes, which aids in solute passage and regulation of blood flow.
What are continuous capillaries.
The 3 variables that control blood pressure.
cardiac output
blood volume
resistance to flow (peripheral resistance)
What is circulatory shock.
Chemoreceptors
In the carotid body and aortic arch
monitor blood chemistry and adjust respiration rate in response to pH and CO2/O2 concentrations
glossopharyngeal -- carotid bodies
vagus-- aortic bodies
The veins with valves.
Fenestrated Capillaries are found here for this purpose.
What are organs that require rapid absorption, that allow for the passage of small molecules but not proteins, through their fenestrations.
arterioles through more muscular, outnumber other arteries, on proximal side of beds, blood has travelled greater distance, and increased resistance.
Causes of Edema.
What are increased capillary filtration, reduced capillary reabsorption, and obstructed lymphatic drainage.
Bonus: Explain why each would cause edema. (100pts)
Baroreceptors
In the carotid sinus
monitor BP and activate mechanoreceptors
work through nerves signaling increase BP due to stretch of arterial wall exposing stretch receptors (PIEZO channel), leading to ions entering and depolarization
What are the 5 types of veins.
What are large veins, venous sinuses, medium veins, muscular venule, and postcapillary venules.
What are sinusoids?
The mechanisms of movement through capillary walls.
What is diffusion
transcytosis
filtration/ reabsorption
Bonus (100pts): explain filtration and reabsorption.
Explain transient ischemic attacks.
Brief episodes of cerebral ischemia caused by the spasm of diseased cerebral arteries. Causes dizziness, vision loss, weakness, paralysis, headache, and aphasia. Often a warning sign of an impending stroke.
Why must astronauts and fighter pilots where pressurized pants?
venous pressure is not enough to force blood upwards and so the blood pools in the lower extremities leading to vascular shock.
List the main differences between veins and arteries.(flow, capacity, structure)
Arteries: Maintain round shape, resilient, pulsatile, high pressure.
Veins: thin walled and flaccid, collapse when empty, steady flow, low pressure.
What are capillary beds?
networks of capillaries that are supplied by a single artery or metarteriole which drain into a metarteriole or venule. The flow into them is controlled by precapillary sphincters.
Are they all open, all of the time?
The way that venous return works.
pressure gradient
gravity
skeletal muscle pump
thoracic pump
cardiac suction
Name each type of low venous return shock and explain it.
Hypovolemic
obstructed venous return
venous pooling (vascular)
septic from infection causing hypovolemic and vascular shock
anaphylactic due to a reaction resulting in hypovolemic and vascular shock
How does the brain monitor its own perfusion
By monitoring pH from dissolved CO2 in the blood.
Hypercapnia triggers vasodilation and increases heart rate/ resp rate
Hypocapnia triggers vasoconstriction and decreases heart rate/ resp rate