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155 Cards in this Set

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What are the parts of the Circulatory System?
Heart, Blood, Blood Vessels,Lymphatic System
Name 4 functions of the circulatory system
Transport
Maintenance of Body Temp
Protection
Buffering
What is the location ,size and weight of the Heart?
middle of Chest- behind sternum /betwn Lungs
Size = 5x31/2 inches
aprox. 300g
Describe the Pericardium and its attachments & major functions
Double walled covering of heart and large blood vessels

Attached to diaphragm (inferior) and major blood vessels (superior)

Also attached to Sternum and Pleural coverings of lungs.

Major function - lubrication - reduces friction.
Describe the make up of the Pericardium (different layers, location,and function)
Made of 2 layers
1.Fibrous outer surface is outer surface of Parietal Pericardium
2. Serous Layer -very thin inner layer- secretes serous fluid.
What are the major functions of the Pericardium?
Lubrication
a. reduces friction as heart beats
b. has a serous membeane which contains serous fluid.
c. Separates Heart from other Thoracic organs.
Describe the make up of the Pericardium(different layers,location and function)
2 Layers:
a. Parietal Pericardium
1. outer layer
2. loose fitting sac
3. made of 2 layers
a. fibrous layer - outer surface, thick & tough,dense fibrous tissue
b. Serous layer - inner surface, continuous w/ visceral Pericdm, very thin SECRETES SEROUS FLUID.

Visceral Pericardium
a. inner layer, continuous with serous layer of parieital percdm -very thin ,clear film tightly covers surface of heart.
Describe the Pericardial cavity
Space between visceral and parietal pericardia

contains serous pericardial fluid.
Describe the 3 layers of the Heart Wall
Epicardium

Myocardium

Endocardium
What is the Endothelium,what type of cells does it consist of and where is it located?
Endothelium simple squamous epithelium that lines the heart ,blood vessels and lymphatic system.
Describe the 3 Layers of the Heart Wall
3 Layers

Epicardium Myocardium Endocardium
What are the Characteristics of the Epicardium?
a. Same as visceral pericardium
b. simple squamous epithlium w/ areolar tissue below
c. often has fat below it on surface of heart - fat fills grooves on heart surface & protects coronary vessels
What are the characteristics of the Myocardium?
Very thick

Mostly cardiac muscle
What are the characteristics of the Endocardium?
a. inner layer
b. lines chambers of heart,covers valves and inside of blood vessels.
c. simple aquamous epithelium with thin layer of areolar underneath
d. often called vascular endothelium
What are the characteristics of the Atria?
a. 2 superior chambers right and left
b.mostly posterior
c. receiving chambers
d each has auricle - small earlike extensions to increase the volume of the atria.
What are the characteristics of the Ventricle?
a. 2 inferior chambers right and left
b. major pumping chambers
c. very thick walls of m yocardium
What are the functions of the valves?
a assure blood flows one way
b. assure blood moves from one chamber to another or to a blood vessel at the right time.

c.
What is the structure of a valve?
a. each valve is made of several cusps

b. cusp is a fibrous flap of tissue covered by endothelium.
What are the AV valves?
atrioventricular valves

a. between atria and ventricles
b. right is tricuspid (3 custards that's alRIGHT)
c. left is bicuspid
What are the Semilunar valves?
btween the ventricles and blood vessels.

Pulmonary Semilunar valve from right ventricle to pulmonary trunk

Aortic semilunar valve from left ventricle to aorta
Give an overview of the Coronary Circulation sytem
1. Left Ventricle mostly pumps blood that will enter the circulation

2. but the Myocardium is a huge mass of muscle that must beat more than once per second
a. it has very high O2 need
b. it needs its own circulatory system to fill these high O2 needs.

3. Blood goes from Left Ventricle to Coronary arteries to coronary veins to right atrium.
Where do the major Coronary Arteries originate?
at the base of the aorta have two arteries branching off, right and left coronary arteries.
Where does the Left coronary artery go?
What are its 2 main branches?
a. passes under the the left auricle
b. 2 branches
1. anterior interventricular artery
-supplies blood to anterior of left & right ventricles
- lies in anterior interventricular septum

2.. circumflex artery
-supplies left atrium & left ventricle
Where does the Right Coronary artery go and what are its main branches
Marginal artery -supplies right atrium and right ventricle

Posterior interventricular artery - supplies blood to posterior of right and left ventricles.
what are the characteristics of Cardiac Veins?
1. Receive blood from Myocardium
2. return blood to coronary sinus
3. basically folow paths of coronary arteries.
What covers all vessels in the sulci of heart?
FAT
What type of cells make up the conduction system of the heart?
a. Made up of high specializeded Cardiac Myocytes.
1. act as if they were neurons
2. able to conduct electrical impules.
what is the SA node?
1. Sinoatrial node
2. Patch of specialized myocytes
3. in wall of atrium
a. just under epicardium
b. near superior vena cava
What is the AV node?
1.Atrioventricular node
2. patch of specialized myocytes in wall between right atrium and left ventricle.
3. near tricuspid valve
What is the AV Bundle?
bundle of His

need more info on this card
Where do the Right And Left Bundle Branches go?
1. From AV Bundle to Purkinje fibers
2. run down through the interventricular septum
Where do the Purkinje Fibers go?
from bundle branches to ventricular myocardium
What makes up the Cardiac Cycle?
1. One heartbeat equals one cardiac cycle
2. consists of:
a atrial contraction and relaxation
b. pause
c. ventricular contraction and relaxation
d. pause
E. repeat
what is the duration and how many beats per minute does the heart beat ?
a. called sinus rhythm
b. .8 sec/heartbeat
c. 70-80 beats p/m
d. over 100,000 heartbeats per day
What is Systole contraction
1. Pressure in chamber increases and ejects blood.
2.atrial systole -both atria contract simultaneously
3. ventricular systole - both ventricles contract simultaneously
longer and larger then atrial systole - clinically systole usually mean ventricular systole.
What happens during Diastole?
1. pressure in chamber decreases and chamber fills with blood.
a. both atria relax at the same time

2. Ventricular - both ventricles relax at the same time- larger and longer thaen atrial
Electrical Events in cardiac cycle.

What happens during SA node?
a. produces elect potential
b. does this spontaneously
1. pacemaker
2. 70 -80 bts p/m
c. slow depolarization
NA+ slowly flowing in
d. fast depolarization
-voltage regulated CA+ channels open causing firing of SA node
Electrical Events in cardiac cycle.


Atrial Systole?
a. electrical impulse from SA node travels through the atrial myocardium and causes muscles to contract.
b. takes about 50 msec to reach AV node
c. blood is pushed from atria into ventricles.
Electrical Events in cardiac cycle.


What happens when impulse reaches AV node?
a. slows signal down for aprox 100 msec
b. delays signal
c. important- gives ventricles time to fill
timing of signal
Trace the impulse as it moves into the Ventricles
AV node
to
AV Bundle branches
to
V bundle down bundle branches
into
Purkinje fibers where the impulse travels very fast - take aprox 200msec.
then
entire ventricular myocardium depolarizes at the same time
What happens at ventricular systole
a. right and left ventricles contract in unison
b. starts at apex and moves up - pushes blood through the semilunar valves.
Pressure changes in Cardiac Cycle

What is Boyles Law?
1.Boyles Law p1v1=p2v2
a. in systole -chambers contract so V decrease and P increases
b. in diastole -chambers relax so v increases and p decreases
How does fluid flow according to Boyles Law?
a. fluid flows from higher pressure to low pressure
b. increase pressure in chamber -ejects blood
c. decrease in pressure in chamber -fills with blood.
How is pressure measured?
a. use barometer
1. column of mercury
2. height of mercury is related to pressure
b. blood pressure meter is modified barometer.
c. unit of presure is= mmHg
What are the phases of the cardiac cycle?
1. quiescent period
2. atrial systole
3. atrial diastole
4. ventricular systole
5. ventricular diastole
What characterizes the Quiescent period?
a. 0.3 - 0.4 sec
b. no chambers are contracting
c. blood is filling atria
d. AV valves are open
-gravity draws 70% of atrial blood into ventricles
e. as ventricles fill with blood ,pressure increases
-V decreases
That makes pressure increase
f. FLAT LINE ON EKG
Describe Atrial Systole
a. atrial contraction
b. SA node fires impulse which travels throughout walls of atria
1. causes depolarization of atrial myocardium
2. P wave on EKG

c. causes contraction of both atria
1. contraction causes further decrease in volume
2. this increases pressure and forces the remaining 30 % of the blood into ventricles.

3. P in atria is now higher than P in ventricles
1. this causes blood to move from atria to ventricles
2. also causes AV valves to stay open. - Semilunar valves are closed.
Describe Atrial Diastole
a. atria repolarize causing atrial diastole
b. impulse passes thru AV node, down the bundle branches and purkinje fibers
Describe Ventricular Systole
a. causes depolarizationof ventricular myocardium
QRS COMPLEX ON EKG
b. ventricular muscles contract which raises the pressure in the ventricles
causes the AV valves to close

FIRST HEART SOUND LUB
c. increase pressure in ventricles causes semilunar valves to open
d. ejects 54% of blood in Ventricles
e. Blood ejected is STROKE VOLUME
What is the Stroke Volume?
blood ejected from Ventricle
what is end systolic volume
blood left in ventricles
what is ejection fraction?
54% is ejection fraction.

can increase with exercise -important measure of cardiac health
What happens during ventricular diastole?
T WAVE ON EKG
ventricular muscles repolarize and expand
c. semilunar valves close as pressure decreases
d. second heart souund (S2 or DUPP)
Heart Sounds

What is S1 Sound?
Lubb

turbulence in blood as AV valves close
What is S2 sound
DUP
turbulence in blood as semilunar valves close
What is possible third sound?
chidren abd young adults
1. may have third sound
triple rhythm
2. S3 rapid filling of ventricles
What is Cardiac output?
amount of blood ejected by each ventricle in one minute.
HR=Heart rate
SV= stroke volume
CO = cardiac output

co=hr X sv
how much blood goes through heart in about one minute?
total volume of blood
What is cardiac reserve?
difference between max CO and resting CO

high in athletes
low with people with heart disease
what is normal heart rate
120 bpm newborns
70 young adults
what are chronotopic agents?
things that raise or lower the heartbeat
what are the 2 major types of chronotopic agents?
autonomic nervous system

chemicals
what are the three inputs from medulla oblonga ?
a. proprioceptors -sensory receptors in muscles
b. baroreceptors -detect blood pressure
c. chemoreceptors - sensitive to ph co2 and 02 in blood
What are the 2 major kinds of chemicals that control heart rate?
Biological and Ions
What are the Biological hormones and neurotransmitters to control heart rate?
a. Epinenehrine and norepinephrine
1. secrecreted by sympathetic nerves and adrenal medulla in response to stress exercise etc.
2. are strong cardiac stimulants.
caffeine and nicotine stimulants.

Thyroid hormone - increases heart rate
What Ions control heart rate ?
Potassium K+ and Calcium Ca2+
Describe K+ affects
a. hyperkalemia- too much potassium
-heart rate becomes slow and irregular and may arrest

b. hypokalemia - not enough K+
- harder for heart to contract, arrythmia interferes with action potential.
- heart may need more stimulation
Describe CA2+ affects
a. hypercalcemia (>CA2+)
-decrease rate
-stronger longer contractions

b. hypocalcemia (<CA2+)
- increases rate
-weaker shorter contractions
Autonomic Nerves
What are the 2 functional parts of the cardiac center in the medulla oblongata?
Cardioaccelatory Center

Cardioinhibitory Center
How does the Cardioaccelatory Center work?
1. Sends signals
thoracic spinal chord

thoracic spinal nerves

SA Node

AV Node and myocardium
2. these nerves release norepinephrine
a. increases heart rate
b. can be stimulated by proprioceptors,baroreceptors and chemocepters
How does the Cardioinhibitory center work?
1. impulses travel through Vagus Nerve to SA and AV nodes
2. vagus nerves secrete acetylcholine
-decrease rate of firing and decreases heart rate.
3. stimulated mostly by baroreceptors.
How does the autonomic nervous system affect the heartbeat?
a. heart naturally wants to go faster.
b. autonomic nervous system regulates firing of the SA node.
1. reduces heart rate
2. SA node receives baseline level of both sympathetic and parasympathetic stimulations
a. sympathetic - more stimulatory
b. parasympathetic - more inhibitory

parasympathetic dominates.
so get overall slowing of heart.
What is Vagal Tone?
the heart wants to go faster

steady parasympathetic input slows heart down

parasympathetic impulses come in via Vagus Nerve

i.e VAgus TOne
What is the function of Blood Vessels
to carry blood thru out body and to and from heart
Where does the exchange between blood and tissue take place?
capillaries
what are the 5 major kinds of blood vessels?
1 arteries
2. arterioles
3. capillaries
4. venules
5. veins
What are the 3 layers of arteries and veins?
1. Tunica externa

2. Tunica Media

3. Tunica interna
What are the characteristics of Tunica externa?
-outermost layer
-loose conective tissue contains elastic and collagen fibers
-stretch and strong
-loose connective tissue is often continuos w/ surrounding tissue and organs helps anchor the blood vessels in place
What are the characteristics of Tunica media?
middle layer
- usually thickest
-mostly smooth muscle
-also contains collage and eleastic fibers
- smooth muscle responsible for vasocontstriction and vasodilation
What are the characteristics of Tunica interna?
-inner layer
- in constant contact with blood
- made of simple squamous called endothelium
-normally repels blood cells & platelets to prevent clots
- platelelts adhere to damaged endothelium -starts clotting mechanism
-acts as semipermeable barrier to blood solutes
-secretes vaso dilaters and vaso constrictors
What are the characteristics of Arteries?
-carry blood away from heart
-usually but not always oxengated
-more muscular than veins
-thicker tunica media
-strong vasoconstric and dilate
What are the charact of Arterioles?
-small arteries
-link arteries to capillaries
-much less smooth muscle than arteries
-vasoconst and dilate a little
What are the character of Cappillaries?
-place where materials are exchanged between blood and tissue fluid
-no smooth muscle or connective tissue
-a single layer of epithelium*
-average 5-9 micrometer in diameter
-organized into capillary beds
-10-100 capillaries supplied by single arteriole
What do precapillary sphincters do?
control of blood flow into the capillaries
What are the Characteristics of Precapillary spincters?
1. Tiny bands of smooth muscle that encircle the entrance into capillaries by arterioles.

2. when sphincters are open (dilated) blood flows freely into capillary bed.

3. When sphincters closed (constricted) blood bypasses the capillary bed.
What are the 2 kinds of capillaries?
1. Continuous
-small solutes can pass thru
2. Fenestrated
-full of pores called fenestrations
- found only in a few places, kidney,small intest, choroids plexus of brain
-large molecules dont pass thru
-speeds up movement of small molecules thru cap walls
function - rapid absorption and filtration of materials.
What are Venules?
Capillaries enlarge into venules
-they drain capillary beds
thin prous walls
-very thin tunica externa
-little or no smooth muscle.
What are Veins?
Carry blood towards heart
-Usually carry deoxygenated blood
-walls are similar to walls of arteries except less smooth muscle (tunic media)
-walls are less elastic than artery walls - tend to collapse when empty.
Characteristics of Blood flow thru Veins
bp in veins is much lower than in arteries
- blood press. not high enough to push blood against force of gravity.
-veins have series of one way valves
-skeletal muscle move,ent also helps push blood thru veins
Where is blood pressure measured?
can be measured in any large blood vessel or heart chamber.

- usually measured in brachial artery of arm
what are the 2 pressures recorded in blood pressure readings?
systolic pressure.
-highest arterial pressure attained during ventricle systole

diastolic pressure
-lowest arterial press. betwen heartbeats- during ventricular diastole.
What is pulse pressure?
the difference between systolic and diastolic press.
what is MAP?
mean arterial pressure

avg pressure exper. by the arteries

calculate by adding diastolic pressure to 1/3 the pulse pressure
What are the functions of blood?
transport
protection
regulation
What does blood transport?
02 and co2
nutrients
waste products
hormones
How does blood protect?
inflammation
- protective response to infection or trauma

leukocytes -destroy microorganisms

antibodies- attack toxins and microorganisms

clotting- prevents blood loss
How does blood regulate body functions?
transports h20 helps maintain water balance

buffers- stabilize Ph

transports hormones
what is the volume of blood?
female- 4-5 l
male 5-6 l
varies w age and % of body fat
What is the PH of blood?
7.35 - 7.45
tolerates very little variation

tightly regulateded by buffers,respiration,kidneys
What is the NaCL salt concentration in blood?
0.9%
same as normal saline
What is the composition of blood?
blood is a connective tissue

plasma (ground substance) 55% by volume

formed elements 45% by volume made of blood cells,platelets
What is Hematocrit?
also called HCT or PCV
measures by volume the blood that is made of cells
generally - 55% plasma
45% Cells
gender difference female lower 42%
male higher 47%
What is serum in blood?
1. not same as plasma
2. plasma w clotting factors removed
3. to produce serum -allow blood to clot then separate liquid (serum) from solids.
What does plasma contain?
proteins
nutrients
gases
electrolytes
what is the most abundant plasma solute?
Proteins -6-9 %
what are the 3 major categories of plasma proteins?
albumins
globulins
fibrinogen
what are the characts. of albumin?
a.small proteins
b. made in liver
c. make up 60% of plasma protein - most abundant
what is the major function of protein in blood?
to determine osmolarity (osmotic pressure) of blood.

1. helps reg water balance betwn blood and tissues
2. strong influence on:
blood press
blood flow
blood volume
What % of plasma proteins is Globulin
36%
What are the three kinds of Globulins?
alpha (smallest)
beta
gamma (largest)
what are the functions of alpha and beta globulins?
made in liver
2. major functions:
a. trnsport molecules for lipids
b. some are hormones
c. some are clotting factors
what are the functions of gamma globulins?
made in the lymphatic tissue by plasma cells.

are the immunoglobulins IgG,IgA etc
What is the function of Fibrinogen in plasma?
4% of plasma proteins

made in liver

a blood clotting factor- precursor of fibrin
What is the major electrolyte in plasma and its function?
90% Na+ -major factor in determining osmolarity
What are the three formed elements of blood?
erythrocytes
leukocytes
platelets
What are characteristics of Erythrocytes?
1. rbcs
2. very small
3. very abundant 99% by number of cells
Describe anatomy of erythrocytes
a. disc shaped
b. ca. 2 micrometers thick
c. biconcave shape - increases surface area for more efficient exchnge of gas -flexibility, they can bend when passing thru small blood vessels
describe mature circulatory erythrocytes
1. no nucleus
2. no mitchrocondria
a. wont consume o2 they carry
b. anaerobic resp only -no protein sysnthesis

Basically BAGS of Hemoglobin
what do erythrocytes contain?
a. hemoglobin
1. carries o2 and little co2
b. CAH
1. carbonic anhydrase
2. catalyzes co2 + h20 -->H2Co3
what does hemoglobin contain?
a. protein
b. made of 4 amino acid chains called
1. globins
2. 2 alpha globins and 2 beta globins
3. some co2 binds to globin units =so hemoglobin transports some co2 also

B. 4 heme groups
1.contain iron fe
2.heme groups bind to o2
3. one o2 per heme group
4. 4 o2 per hemoglobin molecule
what are oxyhemoglobin and doxyhemoglobin?
oxyhemoglobin - Hb with O2 bound to it , red

deoxyhemoglobin - Hb with no O2 bound to it - very dark red.
What are the forms of hemoglobin?
HbA - adult hemoglobin

HbA2
HbF -fetal hemoglobin
its different with age
what is another name for Leukocytes?
WBC's
What is the main function of Leukocytes?
Defense against pathogens
Where are Leukocytes most active?
most active in tissues
a. not very active in the blood
b. use blood mainly for transportation
What is the unique property of Leukocytes?
can pass through the walls of blood vessels
a. rbs cant
b. wbcs are very flexible and highly motile
Leukocytes often have 2 names, what is an example?
monocytes (blood) - macrophages (tissue)

basophil (blood) - mast cells (tissue)
or can change name as they change form and function-
ex. lymphocutes --plasma cells
What are the 2 categories of leukocytes?
a. granulocytes - look granular
1. neutrophils
2. eosinophils
3. basophils
b. agranulocytes - don't look granular
1. lymphocytes
2. monocytes
Describe Granulocytes?
-cytoplasms full of granules
-granules contain antibiotic enzymes (e.g. lysozome)
-short lived
-about 12 hours
-share a common parent called a myoblast
Describe Neutrophils?
60-70% of all leukocytes
- also PMN's
-dull pinkish/grayish granules in cytoplasm
-lobed nucleus
-3-5 lobes
- looks segmented under microscope

functions-
phagocytic
ingest bacteria and viruses
-especially those covered w antibodies
-cant ingest large things
-usually die after 30 mins of phagocytosis
Describe Eosinophils?
2-4% of all leukocytes
-large red granules (orange-pink)
nucleus usually has 2 lobes

Functions:
a. phagocytosis
-only of large molecules
-antigen-antibody complexes
-allergens
- inflammatory chemicals
-not that highly phagocytic
b. cytotoxic enzymes
- release enzymes that kill or weaken pathogens
-very important in protecting against parasites e. g. large organisms such as worms.
Describe Basophils?
-0.5 - 1% of all leukocytes
-large dark purple granules
nucleus large and u shaped
function
secretion of :
heparin - prevents blood clotting
histaine - causes inflammation
note: called mast cells when they enter tissue.
What type of leukocytes are included in the Agranulocytes category?
Lymphocytes and monocytes
Describe lymphocytes
25-30% of all leukocytes
tiny
only slighlty larger than rbs or same size
-round or ovoid nucleus
-small amount of blue cytoplasm

Functions: many functions in immune function
-diifrerent classes of lymphocytes carry out different functions
- ex. secrete antibodies
attack infected cells, immune memory
Describe Monocytes
3-8% of WBC's
biggest
2-3 x larger than rbcs
nucleus ovoid,kidney or u shaped
large pale blue cytoplasm
-called macrophages when in tissue
functions:
highly phagomatic
ingest -debris,bacteria/viruses/small parasites
several monocytes may fuse into a phagoctic giant cell
present antigens to stimulate other cells of immune system.
What are platelets?
-not cells
-also called thrombocytes
-they are fragments of megakarocyte cytoplasm
-megakarocytes live in bone marrow
very tiny -much smaller than rbc's
-no nucleus
What are the functions of platelets?
1. secrete blood clotting factors
2. secrete vasoconstricotrs
-vascular spasm
-prompt constriction of broken blood vessel
-lasts only a few secs.
-lasts just long enough for other mechanisms to stop bleeding.
3. form platelet plugs
- temporary patches a broken blood vessel wall
- platelets stick to collagen fibers in broken blood vessel wall
4. dissolve old blood clots
5. phagotize bacteria
6. attract other leukocytes to site of injury
7.maintain linings of blood vessels
-secrete growth factors for fibroblasts and smooth muscle cells
--
What are the three steps in the process of Hemostasis?
A. Vascular System
B. Platelet Plug
C. Coagulation
Hemostasis:

What happens during Vascular Spasm? What hormone is released?
A. Vascular Spasm
1. most immediate responses to broken vessel
2. rapid constriction of broken vessel
3. platelets release SEROTONIN -a strong vasoconstrictor.
4. Lasts only a few minutes
Hemostasis:

What happens during Platelet Plug?
Platelet Plug:
1. PLatelets adhere to collagen fibers of damaged blood vessel
2. An aggregation of many platelets forms.
3. forms a temporary platelet plug that can stop minor bleeding.
Hemostasis:

What happens during Coagulation?
Coagulation:
1. Clotting of blood
2. last to occur but the most long lasting
3. very complex process
4. very tightly controlled
a, dont want blood to clot when bleeding isnt occuring
b. want blood to clot when bleeding occurs.
Hemostasis:

What protein in plasma is involved in coagulation and what does it transform into?
Fibrinogen (in plasma) ---> Fibrin (sticky protein that forms clot)
Hemostasis:

What are the 2 pathways in the process of Coagulation?
Extrinsic mechanism

Intrinsic mechanism
Hemostasis:

Describe the Extrinsic mechanism in Coagulation
Extrinsic Mechanism:
1.faster than intrinsic
2. involves clotting factors released outside the blood itself
3. involves clotting factors released by the damaged blood vessel.
Hemostasis:

Describe the Intrinsic mechanism in Coagulation.
Intrinsic Mechanism :
Uses clotting factors used inside the blood.
Hemostasis: Clotting Cascade

What happens - Extrinsic Mechanism?
1. Damaged blood vessels release THROMBOPLASTIN.

2. Thromboplastin indirectly activates Factor X
Hemostasis: Clotting Cascade

What happens - Intrinsic Mechanism?
1. Platelets release factor XII (Hagemans factor)

2. Factor XII indirectly activates factor X
Hemostasis: Clotting Cascade

Which clotting mechanism works faster?
Extrinsic pathway works faster than Intrinsic
1. Extrinsic forms clot in about 15 sec.
2. Intrinsic 3-6 min.
Hemostasis: Clotting Cascade

Summarize steps in clotting starting at Factor X
1. Factor X combines with other factors to produce PROTHROMBIN ACTIVATOR

2. Prothrombin Activater converts prothrombin to THROMBIN

3. Thrombin is an enzyme that converts fibrinogen to fibrin.

4. Factor XII converts Fibrin molecules to a fibrin polymer -structural framework of a clot.
Hemostasis: Clot retraction

What happens during clot retraction?
A. Occurs after a clot has been formed
B. Platelets adhere to fibrin strands and contract
C. Clot becomes more compact
D. PDGF - platelet derived growth factor
1. secreted by platelets and endothelial cells
2. stimulates fibroblasts & smooth muscle cells to multiply & repair broken vessel.
Hemostasis: Fibrinolysis

What happens during Fibrinolysis?
a. disslotion of clot
b. after tissue repair is complete
c. also due to reaction cascade
d. uses factor XII
Hemostasis: TPA

What is TPA?
1. Tissue plasminogen activator
2. Given to stroke patients
3. converts plasminogen to plasmin
Hemostasis: Clotting Disorders

What are two clotting disorders?
Hemophilia

Thrombosis
Hemostasis: Clotting Disorders

What is Hemophilia?
1. hereditary clotting disorder
2. usually lack of Factor XIII
3. May be lack of factor IX
Hemosstasis: Clotting Disorders

What is Thrombosis?
abnormal clotting of blood in an unbroken vessel

1. thrombis
a. clot in unbroken vessel
b. may obstruct flow of blood in the vessel
c. stationary

2. embolism
a. clot which break loose from blood vessel
b. travels thru bloodstream
c. can block flow thru vital blood vessel
d. if it lodges in a cerebral ,coronary or pulmonary artery it may cause rapid death.