Random
•Vasoactive chemicals such as histamine and prostaglandins can stimulate vasodilation during trauma, inflammation, or exercise
auto regulation, local control
•retention of sodium which promotes water retention.
•Increases blood volume and pressure
aldosterone
factors that affect stroke volume
heart size
fitness levels
gender
contractility
r•eturn of water and electrolytes to blood plasma due to a combination of blood colloid osmotic pressure and interstitial fluid hydrostatic pressure.
reabsorbtions
If the lymphatic vessels have a blockage, then lymph is unable to return to the bloodstream and accumulates in tissue fluids.
obstructed lymphatic drainage
•negative feedback response to change in BP, carotid bodies in carotid sinus
baroreflex
•- sodium and water excretion.
•Decreases blood volume and pressure
natriuretic peptides
Substances such as oxygen, carbon dioxide, glucose, amino acids, and some hormones cross capillary walls
diffusion
•movement of electrolytes based on concentration gradients whereby substances will travel from high concentration to lower concentration.
facilitated diffusion
______ the volume of blood flowing back to the heart through the systemic veins, occurs due to the pressure generated by contractions of the heart’s left ventricle
_______ is assisted by:
•Venous valves
•Skeletal muscle pump
•Respiratory pump
•Gravity
venous return
response to changes in pH, oxygen, and carbon dioxide concentrations
chemoreflex
•retention of water
•Increases blood volume
antidiuretic hormone
•Large, lipid-insoluble molecules (like insulin) cross capillary walls in vesicles via
transcytosis
water movement whereby osmotic forces will pull water towards wherever solutes are at the highest concentration.
osmosis
•Temporary disruption of blood flow to a part of the brain.
•Most resolve within a few minutes, but rarely causes permanent damage.
•Symptoms: weakness or numbness in face or appendages, confusion, difficulty speaking, vision changes
TIA
response to reduced perfusion of the brain.
medullary ischemic reflex
•vasoconstrictor
•Increases blood pressure
catecholamines
•A passive process in which large numbers of ions, molecules, or particles in a fluid move together in the same direction
•_____is more important for regulation of the relative volumes of blood and interstitial fluid
bulk flow
•increase in hydrostatic pressure or an increase in capillary permeability may increase the amount of water that filters out into surrounding tissues
increased capillary filtration
•Blood clot or plaque obstructs blood vessel, reducing blood flow to the brain.
•Symptoms: speech difficulty, weakness or numbness in face or appendages, vision changes, and sudden severe headache.
CVA Cerebrovascular accidents
•vasoconstrictor and stimulates thirst center.
•Increases blood volume and pressure
•Inhibited by ACE-inhibitors
angiotensin 2
factors that affect HR
hormones
fitness levels
age
•flow of liquid through the membrane due to hydrostatic pressure, allowing only the passage of substances smaller than the fenestration (pore).
filtration
•lack of albumin in blood plasma reduces the reabsorption of tissue fluid (Remember osmosis: wherever solutes are, water follows!).
reduced capillary reabsorption
1.Hypovolemic- a loss of blood volume because of hemorrhage, trauma, bleeding ulcers, burns, or dehydration.
2.Cardiogenic- inadequate pumping by the heart.
3.Obstructive- object compresses a vein
4.Venous pooling shock excess accumulates in the lower limbs
types of shock