Circulatory System 2 Flashcards by Yana Apanovskaya

What is the blood pressure in the aorta? arteries? capillaries? Veins? Vena Cava?

Aorta= 100mmHg
Arteries=97mmHg
Capillaries=35mmHg
Veins= 15mmHg
Vena Cava= 10mmHg

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As the surface area increases, blood pressure ______
What is systolic pressure?
What is Diastolic pressure?
The steepest drop in blood pressure is in the ____ which offer the greatest ____ to blood flow

decreases
the pressure of the blood against the vessels when the heart contracts= systolic
The pressure of the blood against the vessels when the heart is filling= Diastolic
arterioles
resistance

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Arteriole blood pressure reflects which two factors?
Is the amount of blood entering and leaving the blood vessels equal at any time?
arteriole blood pressure is _____ , not constant

The compliance of the elastic arteries close to the heart (how much they can stretch)
The volume of blood forced into them at any time
No it is not.
pulsatile

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what is pulse pressure?
Increased ______raises pulse pressure temporarily
But _____ increases pulse pressure chronically because blood vessels loose their elasticity

the difference between systolic and diastolic pressure
contractility
Atherosclerosis

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What is mean arteriole blood pressure?

Formula?

It is the pressure that propels the blood throughout the tissues
= Diastolic pressure+ (pulse pressure/3)

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What is the formula for blood pressure?

What is blood flow? What is the formula?

= cardiac output x peripheral resistance
Blood flow is the volume of blood flowing through the vessel in a certain given period
= (BP point A - BP point B)/Total peripheral resistance

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What are the 4 factors affecting blood flow?

Length (the longer the lower)
Diameter (larger diameter means less resistance)
Blood viscosity (thicker blood means more resistance)
Obstruction (increases resistance)

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What are the 3 key influencers of blood pressure?

Cardiac output (the higher the output the higher the BP)
Total peripheral resistance (the higher the higher)
Total blood volume (the more the higher)

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Short term regulation of blood pressure is controlled mainly by the _______ system
Long term regulation of blood pressure is controlled via the ______ mechanism.
Short term regulation is about increasing or decreasing _____ and ______
Long term regulation is about increasing _____

nervous system
Renal mechanism
peripheral resistance and cardiac output
blood volume

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Explain the Baroreceptor reflex in short term regulation of BP

Increased blood pressure activates stretch baroreceptors in the carotid sinuses, aortic arch, and in walls of any other large arteries in neck or thorax. Baroreceptors send impulses to cardiovascular centers in the medulla of the brain which inhibit the cardioacceleratory and vasomotor centers and activate the cardioinhibitory center which in turn decreases the BP.
When BP drops the baroreceptors are inhibited, the vasomotor center becomes activated and causes vasoconstriction of vessels and the cardioaccelatory center raises the HR and contractility via sympathetic fibers.

Changes in cardiac output and peripheral resistance maintain blood pressure homeostasis.

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The cardioinhibitory center lowers BP via which 3 mechanisms?

Arteriolar dilation due to inhibition of vasomotor center
Venous dilation- also inhibition of vasomotor center
Decreases cardiac output from inhibition of sympathetic NS and activation of parasympathetic NS to reduce HR and contractility

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The most prominent chemoreceptors for short term regulation of BP are ______ and ______ bodies
which transmit impulses to the ________ center which increases ________ and vasomotor center which increases ________

carotid and aortic bodies
cardio acceleratory center
cardiac output
vasoconstriction

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Which higher brain-centers influence short term blood pressure regulation?

The hypothalamus and cerebral cortex

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Hormones help to regulate blood pressure short term by changing ______ and long term by changing _______

What are paracrines?

peripheral resistance
blood volume
paracrines are local chemicals that facilitate changes in blood flow to support metabolic needs of specific tissues

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Which hormones are generated by the adrenal medulla for BP regulation? What do they do?

Norepinephrine and epinephrine, enhance sympathetic response which increases cardiac output and promotes generalized vasoconstriction

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How does Angiotensin II regulate short term changes in BP?

In order to generate Angiotensin II, the kidneys release ____ which acts as an enzyme

Angiotensin II stimulates intense vasoconstriction which raises systemic BP, and it stimulates release of aldosterone and ADH which regulate BP long-term by increasing fluid retention.

Renin

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How does atrial natriuretic peptide hormone regulate BP short term?
where is it produced?

The atria of the heart produce ANP which reduces blood volume and pressure. ANP antagonizes aldosterone and prods the kidneys to excrete more sodium and water from the body, reducing blood volume. It also causes generalized vasodilation.

How does antidiuretic hormone (ADH) regulate BP short term?

where is it produced?

ADH also called vasopressin, is produced by the hypothalamus and released by the pituitary gland into the bloodstream. It stimulates the kidneys to conserve water.
(water retention = decrease in urine production = increase in blood volume = increase in peripheral resistance = increase in blood pressure)

It is not usually important in short-term blood pressure regulation. However, when blood pressure falls to dangerously low levels (as during severe hemorrhage), much more ADH is released and helps restore arterial pressure by causing intense
vasoconstriction.

Describe the direct renal mechanism in long term blood pressure regulation

when arterial pressure drops filtration by the kidneys is slowed, less fluid leaves the body, volume of blood flow is increased,
When arterial pressure rises too high, filtration by kidneys is sped up, more fluid leaves the body, volume of blood flow is decreased

Describe the indirect renal mechanism in long term pressure regulation

when blood pressure drops Renin is released into blood stream by the kidneys and splits Angiotensinogen plasma protein into Angiotensin I (in the liver)
Angiotensin converting enzyme (ACE) which is found in the capillaries of endothelial tissue (particularly in the lungs) splits angiotensin I into angiotensin II.
Angiotensin II increases water retention and vasoconstriction to raise blood volume and pressure.

Describe 4 ways that Angiotensin II increases blood pressure

Stimulates release of aldosterone by adrenal cortex which enhances renal reabsorption of sodium leading to water retention
Stimulates release of ADH by pituitary gland which reduces urine production
Activates the hypothalamic thirst center to increase water consumption
Increases peripheral resistance as a vasoconstrictor

ADH is secreted by\_\_\_\_\_
Aldosterone is secreted by \_\_\_\_\_
Renin is secreted by \_\_\_\_\_\_
ACE is found in \_\_\_\_\_\_\_
Angiotensinogen is secreted by \_\_\_\_\_\_\_\_

Pituitary 
Adrenal cortex
Kidneys
capillaries of endothelial tissue (lungs)
liver

which vessels contain the greatest volume of blood?

veins and venules (64%)

what does hematocrit mean? what is normal hematocrit?
Blood is ____% of our body weight
The temperature of blood is ______*C
blood pH is _____
Normal volume of blood in females and males?

% of RBC's in blood, approximately 45%
8
38
7.4
females = 4-5L
males= 5-6L

what are the 3 major functions of blood

1. Transport = o2, CO2, waste, hormones 2. Regulation= Temperature, pH, fluid vol. 3. Protection= Immune cells, tissue repair, preventing blood loss

Blood is composed of 55%_____, 45%______, and only 1%______. | When examining a centrifuged blood sample what is the "buffy coat"?

plasma, RBC, and leukocytes+platelets the buffy coat is leukocytes and platelets

plasma is _____% water what type of solute can be found in plasma? Which one is most abundant? _____ accounts for 60% of plasma proteins, it is an important blood _____ and contributes to plasma _____pressure

90 ions, gases, trace elements, vitamins, organic molecules (proteins), inorganic ions (electrolytes) Electrolytes (calcium, chloride, etc) Albumin, buffer, osmotic

What is the difference between plasma and serum?

plasma is the liquid, cell free, part of blood that has been treated with anti-coagulants Serum is the liquid part of blood after coagulation, it is plasma without the clotting factors

What is Hematopoiesis? Where does it take place?

Development of blood cells from a single multipotential hematopoietic stem cell. In the red bone marrow of long bones

Name the 3 most important triggering factors for Hematopoiesis what they do and where they are produced

1. Erythropoietin- produced by kidneys, triggers red blood cell production (erythropoiesis) 2. Interleukins and colony stimulating factors= produced by mature leukocytes and supporting cells of bone marrow, triggers leukopoiesis 3. Thrombopoietin= produced by liver and kidneys, triggers thrombopoiesis (platelet production)

Erythrocytes have a _______shape which allows for a larger ________ and for more attachments of ______ groups for transport of _____ and a faster blood flow. Do erythrocytes have a nucleus? True or False: erythrocytes consume a small percentage of O2 What is the lifecycle of an erythrocyte?

``` biconcave shape surface area Heme O2 No they are anucleate false (they do not require o2) 100-120 days ```

What is Hemoglobin? What percentage of erythrocyte composition is hemoglobin? Describe the life cycle of erythrocytes

a protein that binds to the erythrocyte to transport O2, each hemoglobin protein can carry 4 molecules of O2 Each erythrocyte is composed of 97% hemoglobin 1. When oxygen levels are low the kidneys release erythropoietin (EPO) 2. High levels of EPO promote erythropoiesis in re bone marrow 3. New erythrocytes enter blood stream with a life cycle of 120 days 4. When cells "expire" they get engulfed by macrophages of liver, spleen, and bone marrow where the hemoglobin is broken down and then reused

Leukocytes have _____ making them complete cells. Granulocytes include ____, ____, and _____ Agranulocytes include _____ and _____

Nucleus Granulocytes: Neutrophils (bacteria slayer), Eosinophils (combat parasites, activate mast cells to release histamine), Basophils (release histamine, and heparin) Agranulocytes: Lymphocytes (T-cells, B-cells), and monocytes (macrophages)

Thrombocytes are atypical cells because they have no____, they can reproduce while in the ______, and are considered to be cell _____ they only stick to ______ tissue

nucleus circulation fragments damaged

What is hemostasis? Describe the steps

cessation of bleeding at the site of injury while maintaining normal blood flow elsewhere in the circulation 1. Vascular spasm= vasoconstriction around injured vessel to reduce blood flow and loss, facilitated by chemicals released by damaged cells. 2. Platelet plug formation= Platelets gather at site of injury forming a clot, releasing chemicals that make other platelets stick to collagen fibers at the site 3. Coagulation= If damage is too extensive for platelet plug the enzyme prothrombinase and calcium ions convert plasma protein thrombin into prothrombin and thrombin converts plasma protein fibrinogen into fibrin fibrin forms threads that trap RBC's to form a clot, scar tissue is formed

Describe the 3 phases of blood clot formation (coagulation) and reabsorption (including the extrinsic and intrinsic pathways of forming prothrombin activator)

Phase 1: Intrinsic- RBC trauma (vessel) or contact of RBC with foreign body triggers a SLOW reaction to convert thromboplastin, using calcium and platelet factors, into prothrombin activator Extrinsic -Tissue trauma releases tissue thromboplastin, triggering a FAST reaction to convert thromboplastin into prothrombin activator, using calcium. phase 2: prothrombin activator activates prothrombin which becomes thrombin and converts fibrinogen into fibrin. Fibrin forms a blood clot. Phase 3: Clot retraction and Fibrinolysis. Platelets contract (actin + myosin components) and pull of fibrin strands which release serum and bring the edges of the vessel together, compacting the clot. As clot retraction is occurring the vessel is healing. Once healing is complete the clot is removed via fibrinolysis, when plasma protein plasminogen activates Plasmin (fibrin-digesting enzyme).

What does adenosine diphosphate do? At Which clotting factor do the intrinsic and extrinsic pathways meet?

It is an aggregating agent released by platelets that causes platelets to stick to each other and the damaged endothelium at factor 10A

During coagulation blood is transformed from a liquid into a gel through an activation cascade of ______ factors also called ______ They are named "one" through "thirteen" according to the order of their ______

clotting factors procoagulants discovery

Clot formation is normally complete within __ to __ minutes of vessel damage. Fibrinolysis usually occurs within ____ days of damage and continues for several days until clot is dissolved

3 to 6 minutes | 2 days

In phase one on blood coagulation which pathway (intrinsic or extrinsic) takes place when blood is outside the body such as in a test-tube? Inside the body?

Outside the body only the intrinsic pathway initiates blood clotting because the factors needed for clotting are within the blood and in extrinsic they are released by the damaged tissue. Inside the body both intrinsic and extrinsic pathways can take place