MCAT Biology Chapter 7 The Cardiovascular System

What comprises the cardiovascular system?

HeartBlood Vesselsand Blood

The vasculature consists of ___________ __________ and _______________

Ateries, capillaries and blood

The heart is a _________ _________ Structure

Heart chamber

The heart is composed of ________ _________ that support ___________ different circulations in __________ with one another.

two pumps; two; series

What type of muscle comprises the heart?

Cardiac muscle.

The is the right pump involved with?

pulmonary circulation

With what is the left side of the heart involved with?

Systemic circulation

What is the atria?

upper chambers of the heart

The atria are _______ ________ structures that _____________ blood from either _____________ ____________ or the ____________ _______

Thin-walled; receive; venae cave or pulmonary veins.

What happens to blood inside the atria once it contracts?

Pushed into the ventricles.

What happens to the blood once the ventricles contract?

Send blood to lungs or systemic circulation.

What is the function of pulmunary arteries?

Carry de-oxygenated blood from the heart to the lungs.

What is the function of the pulmunary veins?

carry oxygenated blood from the lungs to the heart.

What is the difference between atria and ventricles?

Ventricles are more muscular than atria

what is the advantage of the ventricles being more muscular than atria?

Allows more powerful contraction

What separates the atria from the ventricles?

atrioventricular valves

What separates the ventricles from the vasculature?

semilunar valves

What is the function of the valves found withing the heart?

Allow the pump to create pressure withing the ventricles.

What are the two purposes of building up pressure inside the ventricles?

Propels blood forward and prevents back flow.

What is the tricuspid valve?

The valve between the right atrium and the right ventricleLAB RAT

what is the pulmunary valve?

separates the right ventricle from the pulmonary circulation.

What is another name for bicuspid valve?

Mitral valve

What is the bicuspid valve?

Is the valve between the left atrium and the left ventricle,LAB RAT

what is the aortic valve?

separates the left ventricle from the aorta.

Both the pulmonary and aortic valve are called ____________

semilunar valves; two

How many leaflets does each valve in the heart have?

tricuspid valve: 3 bicuspid valve: 2 pulmunary and aortic: 3

Why is a more powerful contraction necessary on the left side of the heart?

To maintain the same blood pressure throughout the entire systemic circulation.

Where does impulse initiation occur in the heart?

SA node,

The SA Node generates between _______ to _________ signal per minute without requiring any __________ ___________

60 to 100; neurological input.

Where are the SA node cell located at?

wall of the right atrium

What happens once the depolarization wave spreads from the SA node

the two atria contract simultaneously

Ventricular filling is _________. Explain

Passive; Blood moves from atria to the ventricles based on ventricular relaxation.

What is the role of atrial systole

increase atrial pressure

What is atrial systole?

contraction of the atria

What is the result of increasing atrial pressure?

Forces little more blood into the ventricles.

What is the atrial kick

additional blood volume in the ventricles as a results of atrial systole.

What structure is reached by the signal after the SA node?

The AV node,

Where is the AV node located?

Junction between atria and ventricles

what happens to the signal once it reaches the junction?

Is delayed

What is the function of delaying the signal in the AV node?

Allows ventricles to fill completely before contracting.

what happens to the signal once the signal has been delayed?

travels down the bundle of His and its branches,

Where is the bundle of His located?

embedded in the inter ventricular septum

Where does the electrical signal go after going through the beadle of His?

Purkinje Fibers

What is the function of the purkinje fibers?

distribute the electrical signal through the ventricular muscle.

what connects cardiac muscle cells with one another?

Intercalated discs

What is spacial of intercalated discs?

Areas that contain many gap junctions

What is the function of the gap junctions of intercalated discs?

directly connects cytoplasm of adjacent cell

What is the Overall function of intercalated discs ?

allows coordinated ventricular contraction

What division of the nervous system controls the circulatory system?

Autonomic

How neurological inputs involved in the heart?

Important in increasing or decrease the rate of contractions but not generate it;

What generates contraction in the heart?

SA node (pacemaker cells)

how many phases compose a heart beat?

systole and diastole

What is the effect of the parasympathetic nervous system and the sympathetic nervous system?

Slow HR and contractility rate Increase HR and contractility Rate

Through what nerve is parasympathetic signals provided to the heart?

Vagus nerve

What happens during systole?

ventricular contraction

Aside from ventricular contraction, what also happens during systole?

AV valves close

What happens to the blood inside the heart during systole?

Blood is pumped out of the heart

what happens during the diastole?

Heart is relaxed

Aside from relaxation what is happening valves in the heart during diastole?

Semilunar valves close

What happens with blood in the heart during diastole?

Atria fills the ventricles

What quality allows the vasculature to maintain sufficient pressure while the ventricular muscles are relaxed?

Elasticity of vessels.

what is the cardiac output?

The total blood volume pumped by a ventricle in a minute

What is the formula for Cardia Output

0

What is stroke volume?

volume of blood pumped per beat.

Are the volumes of blood passing through the left and right ventricles the same?

Yes

How will the ANS affect the CO?

PSNS: decrease SNS: will increase

What is the S1 sound?

Two AV valves close at the start of systole

what is the function of AV valves closing at the start of systole?

Prevent backflow into the atria

What is the S2 sound?

Two semilunar valves close at the end of systole

What is the function of two semilunar valves closing at the end of systole?

Prevent back flow into the ventricles

What are S3 and s4 sounds?

Extra sounds of the heart

What causes s3 and s4 sounds?

Stiffness of the heart or Hypertension

The faster the heart beats, the less ____________ is has for ___________ to ____________ the heart during ____________. Therefore, there is a ___________ to how ___________ the heart can _______________ and still pump blood __________.

time; blood; enter; relaxation; limit; fast; beat; effectively

What type of vessels carries blood away from the heart?

arteries

what do arteries branch into?

Arterioles

what do arterioles branch into?

capillaries

What is the function of capillaries?

Perfuse the tissue.

Then, what do capillary networks joint into?

Venules

Venueles fuse to form _________

Veins

Through what two structures does blood enter the heart?

Inferior and superior vena cavae

What type of cells all vessels are line with?

endothelial cells

Endothelial cells help to ______________ ___________ _____________

Maintain blood vessels.

How does endothelial cell help maintain blood vessels?

Releasing chemicals that aid in vasoconstriction and vasodilation.

Endothelial cell allow ______ _____ ______ to pass through the ________ ________ into the _____________ during an _______ __________

White Blood cells; vessels wall; tissue; inflammatory response.

What happens when endothelial cell are damaged?

Releases certain chemicals

What is the function of chemicals that are released when endothelial cell are damaged?

Necessary for blood clot formation

What is the function of blood clots?

Stops bleeding and repair the vessel.

which type of blood vessels contains much more smooth muscle?

arteries relative to veins

what are the only two arteries that carry de-oxygenated blood?

pulmonary and umbilical arteries.

What are arterioles?

Smaller, muscular arteries.

What is one consequences of having arteries that are highly muscular and elastic?

Create tremendous resistance to flow

What is one for the reason why the left side of the heart is much bigger than the right side of the heart?

To overcome the resistance to blood flow.

What is one of the consequences of having arteries that are highly elastic when arteries are filled with blood?

Elastic recoil maintain high pressure and forces blood forward

define capillaries?

vessels with a single endothelial cell layer

How do RBC pass through capillaries?

single file

Capillaries are thin wall, what is the function of this?

allows diffusion of gases, nutrients, wastes and endocrine hormones.

How is a bruise created?

Damaged capillaries

What happens when capillaries are damaged?

Blood leaves and enters the interstitial space

What are Veins

thin-walled, inelastic vessels

Veins carry __________ __________ except the _________ _________ and ________ _________

Deoxygenated blood; umbilical cord; pulmonary vein

what are venules?

Are smaller venous structure

What is the function of venues?

Connect capillaries to larges vein

What gives veins less recoil relative than arteries?

Smaller amounts of smooth muscle

what is one property of veins that allows to accommodate blood volume? Can veins recoil?

stretch. Not recoil

most of the blood returning to the heart comes from the lower part of the body. what mechanism is used to work against gravity?

valves

How do valves of veins function?

Open when blood moves forward and shut when blood tried to move back

Failure of venous valves can result in the formation of ____________ __________ which causes blood to ___________

varicose Veins; pool

Why are pregnant women more susceptible to having varicose veins?

Increase total blood volume and compression of Inferior vena cava

Is smooth muscle enough to propel blood forward?

No

Most veins are surrounded by....

Skeletal muscle

What causes blood to move up through the vein valves?

Skeletal muscle

Through which vessels does blood return from the heart?

through the inferior venae cavae and superior venae cavae.

How does skeletal muscle function to properly blood forward?

Squeezing the vein during contraction

to what chamber of the heart does blood coming from the venae cavae goes to?

Goes into the right atrium

where does blood enter after passing the right atrium?

it enters the right ventricle through the tricuspid valve.

Where does the blood enter after contraction of the right ventricle?

enters the pulmonary arteries through the pulmonary valve

Where does the blood goes after leaving the lungs?

left atrium through the pulmonary vein.

what happens after blood enter the left atrium?

it travels to the left ventricle through the mitral valve.

what happens after the contraction of the left ventricle?

blood enters the aorta through the aortic valve.

How many capillary beds does blood pass before returning to the body?

1

What is a portal system?

Part in which blood passes two capillary beds in series before returning to the heart.

What is the passage of blood after entering arteries to the right atrium?

Arteries to arterioles to capillaries to venules to veins to venae cavea

what are the three portal systems?

hepatic portal system hypophyseal portal system renal portal system

Where does the hepatic portal system begin?

Capillaries beds in wall of the guts

After passing through capillary beds of the gut where does blood go in the hepatitis portal system?

Hepatic portal vein

Where does blood go after passing through the hepatic portal vein in the hepatic portal system?

Capillary beds in the liver

Where does the hypophyseal portal system begin?

Capillary beds of the hypothalamus

To which second capillary bed does blood travel to in the hypophyseal portal system?

Anterior pituitary gland

What happens in the renal portal system

Blood leaving the glomerulus travels through an efferent arteriole before surrounding the nephron in a capillary network called the vasa recta*

Where does the renal portal system begin?

Glomerulus

Where does the blood go to after the glomerulus in the renal portal system?

Efferent arteriole

What is the second capillary bed that is reached in the renal portal system?

Vasa recta

What is the vasa recta?

Capillary network that surrounds the nephron

What is the composition of blood?

55% fluid and 45 % cells.

what is plasma?

Liquid portion of blood

The plasma is an _______ ________

aqueous mixture

What are the three major categories of blood cells?

erythrocytes, leukocytes and platelets

what is an erythrocyte or a red blood cells?

Cell designated for oxygen transport

Red blood cell contain what type of molecule?

Hemoglobin

What 5 things are contained within the plasma?

Nutrients, salts, respiratory gases, hormones, and blood proteins

How many oxygen molecules can a single hemoglobin molecule bind to?

4

What are two advantages of a RBC being bioconcave?

1) Easy to travel in tiny capillaries2) Inc cell surface area for gas exchange

From on what stem cell do all blood cells form? Where do all blood cells from?

hematopoietec stem cell; in the bone marrow

What are RBC unique when mature?

No membrane bound organelles such as nuclei or mitochondria.

Why do RBC not have some membrane bound organelles?

Allows more space for hemoglobin

What is the main source of energy for a RBC? why?

Glycolysis; Do not have mitochondria

What is the main byproduct of RBC metabolism and where does it come from?

Lactic acid; Fermentation

are RBC able to divide?

no

How long do RBC live for?

120 days

What happens to RBC after the 120 day period?

Phagocytize for recycling

What phagocytizes RBC?

Spleen and liver cells

What is hemoglobin measurement?

quantity of hemoglobin in the blood

What is a hematocrit?

Percentage of RBC in a blood sample

What are luekocytes?

White Blood cells that form part of the immune system

The concentration of leukocytes is much lower than the concentration of RBC. When can the concentration of leukocytes increase?

During infection

What are the two types of luekocytes?

Granulocytes and agranulocyte

What is another name for leukocytes

white blood cells

What is contained within the cytoplasmic granules of granulocytes?

Toxic compounds to invading microbes

How do granulocytes empty their granules?

Exocytosis

What three types of cells do granulocytes includes?

Neutrophils, eosinophils, and basophils.

Granular leukocytes are involved in ____________ _________, ____________, ________ formation, and destruction of ___________ and _________

Inflammatory reactions; allergies; pus; bacteria and parasites.

What are agranulocytes?

cells that do not have granules.

Why do granulocytes name granulocytes?

Contain cytoplasmic granules

What types of cells do agranulocytes include?

Lymphocytes and monocytes.

How can we identify granulocytes when seen under a microscope?

Cytoplasmic granules are visible

What are lymphocytes primarily involved in?

specific immune response.

What are lymphocytes primarily involved in?

specific immune response.

What is specific immune response?

A targeted Fight against particular pathogens

some lymphocytes act as ____________ __________ agains an __________ while other function to maintain a _________ ___________ ____________ bank agains of pathogen ___________

primary responders; infection; long-term memory; recognition

Why is a long term memory back important?

Mount a fast response upon exposure to familiar pathogens

Mount a fast response upon exposure to familiar pathogens

B cells and T cells

What are B-cells?

Lymphocytes that mature in the spleen or in lymph

what are t-cells?

lymphocytes that mature in the thymus

B cells are responsible for?

Antibody generation

What are the two function of T cells?

Kill virally infected cells and activate other immune cells.

What are monocytes?

phagocyte foreign matter such as bacteria.

what are macrophages?

monocytes that leave the bloodstream and enter an organ.

The more specific name of macrophages depends on?

where it is located

What is microglia?

macrophages in the CNS

What are langerhans cells?

macrophages in skin

What are osteoclast?

Macrophages in the bone

What are thrombocytes?

Cell fragments released by megakaryocytes

What are megakaryocytes?

Cell in bone marrow

What is the function of thrombocytes?

blood clotting

What is another name for thrombocytes?

Platelets

what is hematopoiesis ?

The production of blood cells and thrombocytes

What triggers the hematopoiesis?

Hormones, Growth Factors, and cytokines

what is erythropoietin

stimulates RBC development

Where is erythropoietin produced?

Kidneys

What is thrombopoietin?

stimulates platelet development.

Where is thrombopoietin produced?

Liver and kidneys

RBC express surface proteins called?

Antigens

What is an antigen?

A specific target to which the immune system can react.

What are the two major antigens families relevant for blood groups?

ABO antigens and RH factor.

The A and B alleles are ___________

Codominant

The O allele is ____________ to _____ and _____ alleles

recessive; A; B

Which blood types is the universal donors?

Type O

Why are O type universal donors?

Will not initiate a immune response

Why will O type not initiate an immune response?

Lack antigens

Can a O blood type receive any blood type? why

No, Capable of creating type A and B antibodies.

Which Blood type is the universal recipients? Why?

Type AB. No antigen is foreign to AB individuals.

What causes antibody creation?

Exposure to an antigen

We would no be expected to have antibodies to an Ebola virus if we have never been exposed to it. Similarly with an Rh factor. However, why do individual lacking an allele for either A or B or both will have antibodies for these antigens without any exposure another persons blood?

E.coli in gut

How does E. coli in the gut allows us to have antibodies to either A or B antigens?

Cave proteins that match A and B alleles

What is the Rh factor?

Another surface proteins expressed on the RBCs.

What does it mean to have Rh+ or Rh-?

The presence or absence of the Rh allele

What allele gives rise to an Rh+?

D allele

What kind of dominance does the Rh factor contain?

autosomal dominant inheritance

What is erythroblastosis Fetalis? Just read

When a woman is Rh- and the baby is Rh+. After birth the woman gets exposed to some fetal blood and creates antibodies. During second pregnancy maternal anti-Rh antibodies can cross the placenta and attack the fetus with an Rh+ maternal anti-Rh antibodies can cross the placenta and attack the fetus with an Rh+ resulting in hemolysis.

Erythroblastosis fetalis results in ___________ of the fetus?

Hemolysis

What is blood pressure?

Is a measure of the force per unit area exerted on the wall of the blood vessels.

How is blood pressure expressed?

As a ratio of systolic (ventricular contraction) to diastolic ( Ventricular relaxation).

What happens to blood pressure when going from arterial to venous circulation?

Gradually drops.

Where in the circulatory system occurs the largest drop in blood pressure and why?

Across artioles.

Why is a huge drop in BP necessary across arterioles?

Capillaries are thin walled and cannot withstand such pressure

What drives cardiac output through a given vascular resistance?

Blood pressure

What is the equation of blood pressure?

CO X TPR

What is the cause of resistance in blood vessels?

larger length and small cross-sectional area.

Arteries are highly _________ and are able to _________ and __________ to change ________ _________ and maintain ________ ___________.

Muscular; expand; contract; vascular resistance; Blood pressure

Arterioles can also __________ to limit the amount of ______________entering a given _______ _______

Contract; blood; capillary bed.

Capillaries are arranged in __________ with each other except the ______ ______

parallel; portal systems

What happens in opening capillary in parallel?

Decrease in vascular resistance (like adding another resistor in parallel)*

What do we use to regulate Blood pressure?

Baroreceptors

Where are the baroreceptors located?

Walls of the vasculature

What are baroreceptors?

Neurons that detect changes in the mechanical forces

What happens when baroreceptors detect low bp?

Stimulate the SNS

That is the effect of the SNS in trying to raise BP?

Causes vasoconstriction

Increases vasoconstriction increases?

Peripheral resistance

What is the function of chemoreceptors in blood?

They can detect osmolarity

What could be indicated if osmolarity is too high?

Dehydration

If osmolarity is too high what is promoted?

the release of ADH

What are the effects of ADH?

Increases blood volume and pressure

What causes the kidney to do when there is low perfusion to the juxtaglumerular cell of the kidney?

Stimulates aldosterone release

What are the effects of aldosterone?

Increases blood volume and pressure

What happens to the nervous system if pressure is too high?

Sympathetic control decreases

What does a decrease in sympathetic control causes?

Relaxation of vasculature

what is the function of aldosterone in blood?

Increases the absorption of Na causing and increase in Volume and pressure.

What releases ANP?

Atrial cells

what is the function of ANP?

lower blood pressure and controls electrolytes

Hemoglobin is a proteins composed of ________ ________ ____________. each has a ___________ _________ that binds to an ____________ _________

Four cooperative subunits; Prosthetic heme; oxygen molecule.

Where does Oxygen binding within the prosthetic group?

Central heme iron atom.

The binding or releasing of oxygen to or from the iron in the heme group is an what type of reaction?

Oxidation reduction reaction

Some oxygen can dissolve in the ________ but this amount is negligible relative to oxygen in the blood cell.

Plasma

What is oxygen saturation?

the percentage of hemoglobin molecules carrying oxygen.

What happens as the first oxygen binds to a heme group?

Induces a conformational change of hemoglobin

What type of conformational does hemoglobin undergoes?

From Taut to Relaxed

What is the advantage of going from T to an R state?

Increases hemoglobins affinity for oxygen

Increased affinity makes it easier for subsequent ________ _________ to bind to the remaining ___________ unoccupied ________ _________

oxygen molecules; three; heme groups

What happens as the other heme groups bind to oxygen?

Affinity to O continued to increase

Once all hemoglobin subunit are bound to oxygen the removal of one oxygen will do what?

Induce a conformation shift

What type of conformational change is induced by the removal of one oxygen?

R to T

What does an R to T do?

Decreases O affinity

How does a decreasing affinity affect the other subunit of hemoglobin?

Makes it easier for other molecules to leave the other heme groups

Hemoglobin exhibits _____________ _________

Cooperative binding

What is cooperative binding?

A form of allosteric regulation.

Explain oxyhemoglobin dissociation curve at rest and exercise. (just read)

O2 sat. is 100% at the lungs with its relative partial pressure. By the time blood reaches the tissues it has 80% sat. with its relative partial pressure. Tissues during exercise it is 30% saturated with its relative partial pressure.

How is hemoglobin relative affinity to CO2 compared to oxygen? How is CO2 transported in the blood?

lower;

What are the three ways CO2 is transporte to the lungs?

Dissolved in bloodCarried by hemoglobinBecomes Bicarbonate ion

What is the first step toward converting CO2 into carbonic acid?

Enters RBC

What is the seconds step after entering the RBC to convert CO2 into carbonic acid?

CO2 is catalyzed by carbonic anhydrase

What is the function of carbonic anhydrase?

Converts CO2 and Water into carbonic acid

What effect does the H+ ions have on blood?

Affects pH

What happens carbonic anhydrase produces carbonic acid?

Dissociates into H+ and Bicarbonate

pH can have ___________ ___________ on the ________________ _________ _________

Allosteric effects; Oxyhemoglobin Dissociation Curve

What happens after H+ and Bicarbonate are produced from carbonic acid?

Dissolves in the blood.

As more CO2 is produce, the bicarbonate buffer equation will shift to the _________ and will ___________ pH

Right; decrease pH

What happens once the H+ and bicarbonate reach the lungs?

Opposite reaction forms CO2

Protons can bind to _____________ reducing its affinity to ____________

Hemoglobin; oxygen

Decreased affinity to oxygen will cause the oxyhemoglobin curve to shift ___________

Right

Right shift of the oxyhemoglobin curve results in ?

Greater unloading of oxygen into the tissues.

The shift to the right of the oxygen hemoglobin dissociation curve due to a decrease in pH is known as?

Bohr effect

What three effects on the blood does exercise have?

Increases CO2Increases [H+]Increases temperature

Aside from Bicarbonate buffer, what else decreases pH during exercise?

Increase in Lactic acid

aside from acids created from CO2 and lactic acid, what other factors cause a righ shift in the oxyhemoglobin dissociation curve?

Inc. temp and increase in 2,3 BPG.

Where does 2,3 - BPG come from?

Side product of glycolysis in RBC

Why does fetal hemoglobin (HbF) has a higher affinity to O than adult hemoglobin (HbA)?

fetal hemoglobin must pull O form mother.

Fetal Hemoglobin shift the oxyhemoglobin dissociation curve to which side?

Left

What is respiratory alkalosis?

Increasing pH due to hyperventilation

What does the body do to compensate for respiratory alkalosis

Kidney increase excretion of bicarbonate, bringing back pH to normal.

What 5 things causes a left shift in the oxyhemoglobin curve?

Decrease CO2, Decrease in H+, increase in pH, Decrease in temp, and Decrease in 2,3 BPG

What is renal tubular acidosis type 1?

When the kidney is unable to excrete acid effectively

What happens if a person buildup too much protons in the body?

Excess of CO2 Forms

How do we get rid of excess H+ if kidneys are not working?

Increase respiratory rate.

What happens in order to compensate for renal tubular acidosis type 1?

Person may increase respiratory rate and bring pH back.

What is hydrostatic pressure?

the force per unit area that the blood exert agains the vessels walls

What generates hydrostatic pressure inside vessels?

Contraction of the heart and elasticity of arteries.

What is the results of hydrostatic blood pressures on the fluid of the bloodstream?

pushes fluid out into the interstitium

What is osmotic pressure in blood?

Sucking pressure generate by solute concentration .

In what direction does osmotic pressure draw water?

Into blood stream

The blood osmotic pressure is usually called_______ _________ because mot of this osmotic pressure is attributable to _______ ________.

Oncotic pressure; Plasma proteins

How are oncotic pressure and hydrostatic pressures at the arteriole end of a capillary end?

Hydrostatic pressure > Oncotic pressure

What is the result of having a greater hydrostatic pressure relative to oncotic pressure?

Net Efflux of water from the circulation

How are the hydrostatic pressure and oncotic pressure at the venue end of the capillary?

Hydrostatic pressure < Oncotic pressure

How does oncotic pressure changes as blood goes from arterioles to venules?

Oncotic pressures stays about the same

What is the result of having Oncotic pressure >hydrostatic pressure?

NEt influx of water into the circulation

What are starling forces?

hydrostatic pressure and osmotic pressure

balancing of starling forces is important for?

Maintaining fluid volumes and solute concentration inside and outside the vasculature.

What is edema?

Accumulation of fluid in the interstitium

Some fluid is also taken up by ____________ _________

Lymphatic system

How is from the lymphatic system return to the circulatory system?

Through the thoracic duct

blockage to the lymph nodes can result from ____________or ___________ and can result in ____________

infection; surgery; edema

Blood clots are composed from?

Coagulation factors and platelets

What are coagulation factors?

Proteins

Coagulation factors are activated because they can ________ _____ _____.

Sense tissue factor

What does the activation of coagulation cascade lead to?

Activation of prothrombin

What is the function of prothrombin?

form thrombin

What is the function of thrombin?

Convert fibrinogen into fibrin

What is the role of fibrin?

Form small fibers

What is the function of clots?

Prevent or minimize blood loss

What is the function of the fiber formed by fibrin?

Aggregate over the damaged area like a net

What happens hen endothelium of a blood vessel is damaged?

It exposes the underlying connective tissue.

What will the net-like structure formed by fibrin do once aggregated?

Captures RBC and Platelets

What does the connective tissue have in the blood vessel?

Collaged and tissue factor

Where does the clot form?

Surface of vessel that has been cut

What is the tissue factor?

A protein

What is plasmin?

Breaks a clot down,

What happens when platelets come into contact exposed collagen?

They release their content and begin to aggregate.

As platelets aggregate and release their contents, what is occurring simultaneously?

Coagulation factors initiate a complex activation cascade.

Where are coagulation factors secreted?

Liver

What is the precursor of plasmin?

plasminogen