Lec 14 Arteriol resistance, blood distribution, cardiovascular regulation, lymphatic system

what is ACTIVE Hyperemia vs REACTIVE hyperemia?

Active Hyperemia= locally mediated increase in blood flow that matches a normal increase in tissue metabolic activity.

• General Location: Arterioles supplying skeletal muscles or organs during workload shifts.

VS

Reactive Hyperemia= An increase in tissue blood flow that occurs after a temporary period of completely blocked or occluded flow.

• General Location: Tissue beds downstream from a temporary compression or blockage.

what is Atrial Natriuretic peptide ANP vs angiotensin,

ANP= peptide hormone that acts as a potent vasodilator to reduce blood pressure when the heart detects high fluid volumes.

• General Location: Synthesized and released by the atrial myocardium; acts on systemic blood vessels and kidneys.

Angiotensin II (ANG II)= plasma hormone that causes intense vasoconstriction to rapidly increase blood pressure.

how does parasympathetic vs Sympathetic differ in cardiovascular control?

what is microcirculation?

=structural structural network consisting of arterioles, metarterioles, capillaries, and venules where flow regulation and exchange happen.

• General Location: Spanned across all vascularized tissues throughout the body.

what is Tunica Intima & Endothelium?

= thin inner lining layer of all blood vessels, made up of a single layer of flattened endothelial cells that secrete paracrine signals.

• General Location: The inner lumen surface wall of every vessel in the cardiovascular tree.

what are metarioles? . Precapillary Sphincters?

Metarioles= Microcirculatory bypass vessels that bridge arterioles directly to venules, acting as alternative pathways.

• General Location: Branching directly out of terminal arterioles.

• Analogy: A highway HOV or express lane that allows traffic to bypass busy city streets when exits are closed.

Precapillary Sphincters= Rings of smooth muscle that open or constrict to directly route blood into true capillaries or divert it into metarteriole bypasses.

• General Location: At the structural junction where capillaries branch off from a metarteriole.

continous VS fenestrated VS sinusoid capillaries, how do molecules pass through? where are they commonly found?

what is paracellular pathways vs endothelial pathways? what is difussion vs transcytosis?

what is bulk flow? what is filtration vs absorption and what do they each entail for fluid movement? what is NET pressure calculation and how does it differ in arterial end vs venous end?

Hydrostatic Pressure (PH)

• What & Function: The mechanical fluid pressure exerted by blood against the inner vessel walls, pushing fluid out.

• General Location: Inside the capillary lumen, dropping steadily from the arterial end to the venous end due to friction.

Colloid Osmotic Pressure(pi / Oncotic Pressure)

• What & Function: The osmotic pull created by trapped, non-penetrating plasma proteins that draws water back into the blood.

• General Location: Inside the capillary blood plasma

what is cardiovascular control center, baroreceptors and baroreceptor reflex?

Baroreceptors & Baroreceptor Reflex

• What & Function: High-pressure mechanoreceptors that continually monitor arterial stretch to execute fast homeostatic control over systemic blood pressure.

• General Location: Embedded in the walls of the carotid arteries and the aorta.

what is purpose of lymphatoc system?

Lymph & Lymph Capillaries

• What & Function: Blind-ended, highly porous fluid vessels that collect excess filtered tissue fluid and proteins (turning it into lymph) to return it to the veins.

• General Location:

  Interspersed right alongside true systemic capillary beds throughout tissue spaces.

*a net avg of 3L/day of fluid filters out of capilarries , the excess h20 and solutes that are filtered out are picked up by lymph and returned to circulation

• LYMPH NODES= filled with immune cells that actively filter fluid for pathogens before returning it to the blood.

how does velocity of blood flow differ in aorta, arteries, arterials, capillaries, venues, veins, nenae cava (rank them)

where is most blood distributed throughout the body at rest? what is it governed by?

what is key about vascular smooth muscle and sympathetic system?

what are 2 keys VASOCONSTRICTORS and 3 key VASODILATORS, what is their general purpose?

what is arteriol resistance? what is myogenic autoregulation and it’s purpose?