Reading...
Play button
Play button
Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
118 Cards in this Set
- Front
- Back
|
In what direction does arterial blood always flow.
|
Arterial blood always flows away from the heart.
|
|
|
What do capillaries do?
|
Capillaries exchange materials like gases, hormones, and nutrients between blood and interstitial fluid.
|
|
|
In what direction do veins carry blood?
|
Veins always carry blood toward the heart.
|
|
|
What is endothelium?
|
An endothelium is a single layer of simple squamous cells that line the walls of the heart, blood vessels, and lymphatic vessels.
|
|
|
Are vessels organs, and what constitutes an organ?
|
Blood vessels are organs. Organs are defined as having more than 2 tissues.
|
|
|
What are CAMs?
|
Cell adhesion molecules are proteins on the cell surface involved with binding with other cells or with binding to the extracellular matrix in the process called cell adhesion.
|
|
|
What are some unique properties of endothelium?
|
The endothelium is a selectively permeable barrier, it also secretes chemicals, and makes CAMs when inflamed that attracts leukocytes.
|
|
|
What is the vessel lumen?
|
The lumen is the blood-containing space in the vessel.
|
|
|
The walls of all blood vessels, except for the very smallest, have 3 distinct layers, what are their names?
|
The tunica intima, which is also known as the endothelium it is the innermost layer, the tunica media is the second innermost, and the tunica externa is the outermost.
|
|
|
What is the tunica intima composed of?
|
The tunica intima is composed of endothelium and is larger than 1mm thick in large vessels.
|
|
|
What is the tunica media composed of, and what is its purpose?
|
The tunica media is mostly smooth muscle, and it provides vasomotion.
|
|
|
What is vasomotion?
|
Vasomotion is the change in a blood vessels diameter.
|
|
|
What does vasodialation and vasoconstriction mean?
|
Vasodialation means to open a blood vessel and vasoconstriction means to close a blood vessel.
|
|
|
What does the prefix vaso mean?
|
Vaso means blood.
|
|
|
What is the purpose of the tunica externa?
|
This tunica externa contains the vaso vasorum.
|
|
|
What is the vaso vasorum?
|
Vaso vasorum means vessels of the vessels, and acts as the private blood supply of vessels.
|
|
|
How does Viagra work?
|
Viagra works by releasing nitric oxide (NO), which causes smooth muscle relaxation, increased blood flow, and better erections. Hence, Viagra is a potent vasodialator.
|
|
|
Name and briefly describe the three types of arteries.
|
• Large or elastic arteries are called conducting arteries that act like I-5 or I-90.
• Medium or muscular arteries are called distributing arteries that act like entrance/exit ramps and state highways. • The smallest arteries are called arterioles that link arterioles to capillaries, and contain precapillary sphincters. |
|
|
What are precapillary sphincters, and what division of the ANS controls these?
|
Precapillary sphincters are bands of smooth muscle that adjust the blood flow going into the capillaries. These can open and close with sympathetic stimulation.
|
|
|
What are the three kinds of arterial sense organs, and how do they work?
|
a. The carotid sinus is innervated by the ANS, and contains baroreceptors, which work to maintain blood pressure.
b. The carotid bodies contain chemoreceptors, which work to measure oxygen, carbon dioxide, pH, and temperature levels, these messages are carried via afferent verves to the CNS. c. Aortic bodies send afferent messages about blood pressure, oxygen, and carbon dioxide levels to the CNS. |
|
|
What is an aneurysm?
|
An aneurysm is a localized blood-filled dilation caused by disease or weakening of a blood vessel wall.
|
|
|
What is a dissecting aneurysm?
|
A dissecting aneurysm is the pooling of blood between tunics.
|
|
|
What does tunic mean?
|
Tunic means covering or coat.
|
|
|
Roughly how many capillaries are there in the body, what are they composed of, and roughly how close are they to any cell?
|
There are about one billion capillaries in the body, they’re composed of endothelium and a basement membrane, and cells are always within 60-80 um (about 5-6 cell widths) of a capillary bed.
|
|
|
Roughly how much blood is in the capillaries at any one time?
|
There is roughly 250-300ml of blood in the capillaries at any given time.
|
|
|
What are some examples of conducting arteries?
|
Some conducting arteries: aorta, common carotid, subclavian, pulmonary trunk, and common iliacs.
|
|
|
Name and describe the three kinds of capillaries, and list where they are found in the body.
|
• Continuous capillaries are found in skin and muscle, are the most common of capillaries, and form an uninterrupted lining with their endothelium being connected laterally plasma membrane-to-plasma membrane via tight junctions.
• Fenestrated capillaries have windows that material is able to get in and out of, and they're found in kidneys, endocrine glands small intestine, choroid plexuses • Sinusoids are large windowed versions of fenestrated capillaries that are able to pass blood cells and serum proteins through its walls, and they're found in liver (Kupffer cells), bone marrow, spleen. |
|
|
What is fesestra?
|
Fenestra is latin for window.
|
|
|
Where are sinusoids found?
|
Sinusoids are found in the liver, bone marrow, and spleen.
|
|
|
Where are fenestrated capillaries found?
|
Fenestrated capillaries can be found in the kidneys, endocrine glands, small intestine, and choroids plexuses.
|
|
|
31. What are the choroids plexuses?
|
The choroids plexuses make and distribute cerebral spinal fluid.
|
|
|
32. What are Kupffer cells?
|
Kupffer cells are macrophage cells that are part of the immune system.
|
|
|
33. Are capillaries ever found alone?
|
Capillaries are only found in beds of capillaries and never alone.
|
|
|
34. Roughly how much blood does the brain always need to function?
|
The brain always needs about 750ml to function.
|
|
|
35. List the approx breakdown of how much blood is distributed throughout the body at any given time.
|
• 60% in systemic veins and venules
• 15% in systemic arteries and arterioles • 12% in pulmonary blood vessels • 8% in the heart • 5% in the capillaries |
|
|
36. What is a shunt?
|
A shunt is moving blood from one area to another.
|
|
|
36. What are capacitance vessels, and what major organ acts as a blood reservoir?
|
Capacitance vessels are blood reservoirs, and the spleen acts as a blood reservoir, blood is stored on a basis of volume and BP.
|
|
|
37. What are venous valves?
|
Venous valves are folds of the inner lining that work to keep blood flowing in one direction.
|
|
|
38. How do large-diameter veins affect blood supply?
|
Large-diameter veins act like a river, in that the water flows fastest in the middle of the river, large-diameters help blood travel quickly.
|
|
|
39. What are varicose veins, and what can cause them?
|
Varicose veins are veins that become large and twisted because of pooling blood and pressure on valves. They can be caused by standing on your feet for long periods.
|
|
|
40. What are hemorrhoids?
|
Hemorrhoids are varicose veins of the rectum.
|
|
|
41. What are venules?
|
Venules bring de-oxygenated blood from the capillaries to the veins.
|
|
|
42. What are veins?
|
Veins carry blood to the heart.
|
|
|
43. What are venous sinuses, and where can they be found??
|
Venous sinuses have especially thin walls and have no muscle, and they can be found in the coronary sinus of the heart, and the dural sinuses.
|
|
|
44. What are vascular anastomoses?
|
Anastomoses provide alternate pathways for blood to reach its destination if its route is blocked.
|
|
|
What does anastomoses mean?
|
Anastomoses means coming together.
|
|
|
What is the most common circulatory route?
|
Heart→Arteries→Capillaries→Veins→Heart
|
|
|
What is the portal system, and name two examples?
|
A portal system is when one capillary system is connected to another capillary system through veins. This is found in the hypothalamus and the liver.
|
|
|
What are some examples of anastomoses?
|
When two vessels merge, arteriovenous shunt bypasses capillaries (fingers, toes, ears), venous (one vein to another), and arterial (two arteries).
|
|
|
What is blood flow?
|
Blood flow is the amount of blood flowing through an organ or the body, and when considering the entire vascular system it’s also referred to as CO.
|
|
|
What is perfusion?
|
Perfusion is the flow per given volume or mass of tissue, and is described as: ml/min/g. Equal output per weight of an organ.
|
|
|
What is blood pressure?
|
Blood pressure is the force blood exerts on a vessel wall, and is measure in millimeters of mercury.
|
|
|
Describe what 120mm Hg is.
|
120 mm Hg describes the pressure exerted by a column of mercury 120 mm high.
|
|
|
What is MAP, and why is it important?
|
Because diastole usually last longer than systole, mean arterial pressure is roughly = diastolic pressure + 1/3 pulse pressure. This is important because aortic pressure fluctuates up and down.
|
|
|
What is pulse pressure chronically increased by and why?
|
Pulse pressure is chronically increased by arteriosclerosis because the elastic arteries become less strechy.
|
|
|
What is systolic pressure?
|
Systolic pressure is pressure exerted by blood on the blood vessel walls during ventricular contraction.
|
|
|
What is diastolic pressure?
|
Diastolic pressure is the blood pressure reached during or as a result as ventricular diastole, it is the lowest pressure of any cardiac cycle.
|
|
|
What is pulse pressure, and how is this felt?
|
Pulse pressure is the difference between systolic and diastolic pressure. (120mm Hg systolic pressure - 80 mm Hg diastolic pressure = 40mm Hg pulse pressure.) Pulse is felt as the throbbing of an artery during systole.
|
|
|
What would be the MAP for a person with a 120 mm Hg systolic pressure and a 80 mm Hg diastolic pressure?
|
MAP (mean arterial pressure)=Diastolic + (Systolic - Diastolic)/3
80 + (120-80)/3 = 93.3mm Hg |
|
|
What is hypertension?
|
Hypertension is an unusually high blood pressure.
|
|
|
What is hypotension?
|
Hypotension is an unusually low blood pressure.
|
|
|
What is hydrostatic pressure?
|
Hydrostatic pressure is blood pressure on the vessel wall.
|
|
|
List the arterial, capillary, and venous average pressure gradients, and what affects these changes?
|
• Arterial: 100→35mmHg (its 35mmHg when enters capillaries)
• Capillary: 35→18mmHg (BP drop due to friction encountered, takes about 1→2 seconds for RBC to cross capillary) • Venous: 18→1mmHg (when kidneys filter blood they get about 20%) |
|
|
How are action potentials affected by pressure gradients?
|
Action potentials are affected by electrochemical gradients when there is an influx of NA+ ions and then a short influx of P+ ions because of the electrical difference of the extracellular and intercellular space.
|
|
|
Describe how fluid flow moves as related to resistance.
|
A moving fluid has no pressure unless it encounters at least some resistance.
|
|
|
What is blood viscosity?
|
Blood viscosity is the resistance to flow and is related to the thickness, or stickiness of blood.
|
|
|
How would EPO affect blood viscosity?
|
Erythpoietin is a hormone that promotes RBC formation, more RBCs would cause the blood to be more viscous.
|
|
|
What are the three factors that affect resistance?
|
The three factors that affect resistance are blood viscosity, total vessel length, and the blood vessel diameter (vasoconstriction & vasodialation).
|
|
|
What is laminar flow?
|
Laminar (layer) flow is faster near the center and slower near the walls.
|
|
|
What is the relationship among flow, pressure, and resistance?
|
Flow = change in pressure/resistance, or Flow (CO) = Δpressure/Resistance
|
|
|
What affects arterial blood pressure (systolic and diastolic)?
|
Arterial BP is affected by the elasticity of the arteries and the volume of blood.
|
|
|
What is one way to lower blood volume?
|
A diuretic could be taken to cause urination, and a decrease in blood flow.
|
|
|
How is arterial blood pressure measured?
|
Arterial blood pressure is measured by pulse pressure (systolic – diastolic), and MAP (Diastolic + pulse pressure x 1/3).
|
|
|
Why does calculating MAP involve dividing the pulse pressure by a 3rd?
|
Calculating MAP involves dividing by a 3rd because diastole lasts longer than systole.
|
|
|
What is the usual capillary BP?
|
The normal capillary BP is goes from 35→18mmHg
|
|
|
What two things affect venous BP?
|
Venous BP is affected by the respiratory pump (pressure Δ in the ventral cavity), and the muscular pump (skeletal muscle).
|
|
|
What are the three ways to control vasomotion?
|
• Local control: let the local tissues decide what blood flow
• Short-term mechanisms: neural controls • Autonomic reflexes |
|
|
What is the metabolic theory of autoregulation?
|
The metabolic theory of autoregulation states automatic adjustment of blood flow to each tissue in proportion to the tissue’s requirements at any instant.
|
|
|
72. What is hypoxia, and what could cause it?
|
Hypoxia means deficient in oxygen, and could be caused by carbon dioxide, hydrogen, potassium, lactic acid, and or adenosine accumulation.
|
|
|
What are vasoactive chemicals, and list some examples?
|
Vasoactive chemicals cause either vasodialation or vasoconstriction. Histamine is a vasodilator, and nitric oxide is a vasodialator.
|
|
|
What is reactive hyperemia?
|
Reactive hyperemia is the transient increase in organ blood flow that follows a brief period of ischemia.
|
|
|
What is angiogenesis?
|
Angiogenesis will create more blood vessels if needed.
|
|
|
What does angio mean?
|
Angio means vessel.
|
|
|
What does genesis mean?
|
Genesis means to create.
|
|
|
What is the role of the vasomotor center, and where is the vasomotor center located?
|
The vasomotor center controls heart rate, BP, respiration, and is found in the medulla.
|
|
|
What is vasomotor tone?
|
Vasomotor tone is a sympathetic signal that innervates the smooth muscle of blood vessels, mostly arterioles. As a result the arterioles are almost always in a state of moderate constriction of vasomotor tone.
|
|
|
Where are the primary blood pressure centers?
|
The primary blood pressure centers in the body are the carotid and the aortic sinus.
|
|
|
What are the primary and secondary functions of chemoreceptors?
|
The primary function for chemoreceptors are to measure respiration, and the secondary function is to measure for vasomotor center in medulla.
|
|
|
Is it possible for the higher brain centers to have control BP?
|
Yes, like when you hold your breath.
|
|
|
What is the medullary ischemic reflex?
|
The medullary ischemic reflex is an automatic response in perfusion of the brain.
|
|
|
What are the four short term mechanisms (chemical controls), and list examples.
|
• Adrenal medulla hormones will amplify heart rate: NE, E
• Endothelium-derived factors: Endothelin (among the strongest vasoconstrictors known) and PDGF (platelet-derived growth hormone, plays a big part in angiogenesis) both cause vasoconstriction • Nitric oxide as a EDRF (endothelium-derived relaxing factor), is a powerful vasodialotor • Inflammatory chemicals • Alcohol is a vasodialotor |
|
|
What are long-term mechanisms: renal regulation
|
Long term affects are to maintain target blood volume.
|
|
|
What do the kidneys do?
|
The kidneys primary function is to maintain homeostasis of bodily fluids like urine, and plasma. Because the kidneys are poised to sense plasma concentrations of compounds such as sodium, potassium, hydrogen ion, oxygen, and glucose, they are important regulators of blood pressure, glucose metabolism, and erythropoeisis.
|
|
|
What is erythropoeisis?
|
Erythropoeisis is RBC formation.
|
|
|
What are the ballpark numbers that describe hypotension and hypertension?
|
Hypotension = 60, hypertension = 130
|
|
|
What does edema mean?
|
Edema is an increase in interstitial fluid of any organ, seen as swelling.
|
|
|
In terms of autoregulation/local regulation, what are some metabolic controls that affect BP?
|
• Hypoxia will stimulate vasodialation (CO2, H+, K+)
• Vasodialators like NO and prostacyclin • Vasoconstrictors like endothelins |
|
|
In terms of autoregulation/local regulation, what are some myogenic controls that affect BP?
|
These are inherent response of arteriole smooth muscle (resists the stretch = and causes constriction).
|
|
|
In terms of autoregulation/local regulation, what are some reactive hyperemia controls that affect BP?
|
Reactive hyperemia is a transient increase in organ blood flow that results from ischemia.
|
|
|
What does myogenic mean?
|
Myo = muscle, genic = generate
|
|
|
In terms of autoregulation/local regulation, what are some long-term control controls that affect BP?
|
Autogenesis would be a long term regulator.
|
|
|
Describe capillary exchange in areas of the body including the brain.
|
Microcirculatory exchange is a continuum, and is done so by diffusion except in the brain, where the blood brain barrier comes in to play.
|
|
|
Describe the path that blood takes through the capillaries to the cells.
|
Blood goes from the capillaries, to the interstitium, and to the cells.
|
|
|
How do chemicals pass through the endothelial cytoplasm?
|
They pass through clefts between the endothelial cells, and through fenestrations, or fenestrated capillaries.
|
|
|
Describe fluid movements of blood going through the arteriole side of the capillary to the venous side of the capillary.
|
Fluid filters out of the arterial end of a capillary and osmotically reenters it at the venous end.
|
|
|
Describe filtration as it relates to capillary exchange.
|
Filtration is a process in which hydrostatic pressure forces fluid through a selectively permeable membrane.
|
|
|
What are two examples of hydrostatic pressure?
|
Blood pressure and capillary pressure are examples of hydrostatic pressure.
|
|
|
Describe how colloid osmotic pressures relate to capillary exchange.
|
Colloids are large particles, usually proteins, because they don’t easily pass through the capillary membrane easily, this pressure helps get through.
|
|
|
What is the starling law of the capillaries?
|
The starling law of the capillaries says what comes in goes out.
|
|
|
What is the formula for NFP, and what does NFP mean?
|
The formula for Net Filtration Pressure at the arterial end is as follows:
NFP = (HPc – HPif) – (OPc – OPif) NFP = (35 – 0) – (26 – 1) = (35 - 25) = 10mm Hg The formula for Net Filtration Pressure at the venous end is as follows: NFP = (OPc – OPif) - (HPc – HPif) NFP = (17-0) – (26 – 1) = -8mm Hg _________NFP means who is pushing and who is pulling |
|
|
What are the 6 factors for Fick’s law of diffusion?
|
• Permeability
• Gradients, concentration gradients (steepness) • Distance to diffusion (closeness of cell & capillary, thickness of wall, diameter of vessel) • Surface area • Size of molecules • Rate of flow is slow. |
|
|
How close is every cell to a capillary?
|
Every cell is at least 4/1000 inch from capillary
|
|
|
Approximately how thick is a capillary wall, and how far across a capillary?
|
A capillary wall’s diameter is approx 1um, and across a capillary is approx 7-8um.
|
|
|
How much surface area would all the capillaries in body cover, what is approx percentage of capillary blood, and describe this figure in ml?
|
Roughly the surface of a gym floor, only about 5% blood in capillary, 250ml capillary blood/5250ml in whole body.
|
|
|
How and why would oxygen and carbon dioxide diffuse through capillaries?
|
Oxygen and carbon dioxide would diffuse regularly because they’re so small.
|
|
|
What are two endothelium derived factors, and what are their effects.
|
Nitric Oxide vasodilates and endothelin & PDGF (platelet derived growth factor) vasoconstrict.
|
|
|
What long term mechanism can affect circulation.
|
Renal regulation by the kidneys
|
|
|
What short term mechanisms can regulate BP, and give examples of each?
|
Neural: vasomotor tone (sympathetic), baroreceptors, and chemoreceptors.
Hormonal: NE, E, ADH (vasopressin is vasoconstrictor), Endothelin derived: endothelin and NO. |
