Cardiac Physiology Exam

what are the three specific functions of the blood

1. transport

2. protection

3. regulation

what hormone has to be present for red blood cells to be produced

erythropoietin (EPO)

define thrombosis

a serious condition that occurs when a blood clot, or thrombus, forms in an artery or vein

what organ is red blood cell grave yard

spleen

define leukopoesis

production of white blood cells

define erythropoesis

RBC production

Types of ions that need to be present or clotting to occur

• Procoagulants or clotting factors

• factor XII

• factor XI

• factor IX

• factor VIII

• factor X

• prothrombin activator

• thrombin

• fibrin

define biliverdin

heme pigment is converted to biliverdin (green), biliverdin is converted to bilibrubin (yellow)

heparin

• from basophils and mast cells

• interferes with formation of prothrombin activator

what factor initiates intrinsic blood clotting pattern

• initiated by platelets releasing hageman factor (factor XII)

• cascade to factor XI to IX

• in presence of Ca++ and PF3 activates VIII to X

• calcium is required for either pathways

factor involved in positive feedback loop that allows thrombin to activate

Thrombin participates in a positive feedback loop by activating factors V (FV) and VIII (FVIII), which are cofactors in the prothrombinase complex, and factor XI (FXI), thereby amplifying thrombin generation and accelerating the coagulation cascade. 

extrinsic pathway for blood clotting

• initiated by release of tissue thromboplastin (factor III) from damaged tissue

• Factor III combines with factor VII

• in presence of Ca ++ activates factor X

Define aerobic respiration

A chemical process in which oxygen is used to make energy from carbohydrates (sugars)

what is the difference between aerobic and anaerobic respiration

• Cellular respiration that proceeds in the absence of oxygen is anaerobic respiration.

• Cellular respiration that proceeds in the presence of oxygen is aerobic respiration

when does ventricular filling occur

during diastole, specifically when ventricular pressure falls below atrial pressure

where are your cardiac centers located

the medulla oblongata of the brain

what receptors are in the skeletal muscles that increase heart rate

During exercise, skeletal muscle metaboreceptors and mechanoreceptors, particularly group III and IV afferent sensory neurons, play a crucial role in increasing heart rate by activating the exercise pressor reflex, which leads to increased sympathetic nerve activity and decreased parasympathetic activity. 

Does the SA node have a stable resting membrane potential

• Normal heartbeat triggered by the SA node

• No, the SA node cells do not have a stable resting membrane potential; instead, they exhibit an unstable resting potential that spontaneously depolarizes, a process known as the pacemaker potentia

electrocardiogram (ECG) waves

1. P = atria begin depolarizing

2. atrial depolarizatuion complete

3. QR = ventricular depolarization begins at apex and progresses superiorly as atria repolarize

4. RS = ventricular depolarization complete

5. T = ventricular repolarization begins at apex and progresses superiorly

6. ventricular repolarization complete; heart is ready for next cycle

largest arteries

conducting

classifications of artery sizes

1. conducting - large

2. distributing - medium

3. resistance - small

which capillary is located in most tissue

continuous capillaries

define hemodynamics

• physical principles of blood flow based on pressure and resistance

  • the greater the pressure difference between two points the greater the flow

  • the greater the resistance the less the flow

define vaso reflex

• changes in vessel radius

  • vasoconstriction

  • vasodilation

colloid osmotic pressure (COP)

• draws fluid into capillary

  • Results from plasma proteins (albumin) - more in blood

  • Oncotic pressure = net COP (blood COP - tissue COP)

on the arterial end, which is greater hydrostatic or colloid osmotic pressure

hydrostatic pressure is high on arterial end of capillary, low on venous end

what are the general properties of the blood

liquid connective tissue consisting of cells and extracellular matrix

• plasma

• formed elements

what are erythrocytes also known as

red blood cells (RBC’s)

what are leukocytes also known as

white blood cells

name all the formed elements of the blood

• red blood cells

• white blood cells

• platelets

name all the divisions of leukocytes

• granulocytes

  • neutrophils

  • esinophils

  • basophils

• agranulocytes

  • lymphocytes

  • monocytes

describe granulocytes

A type of immune cell that has granules (small particles) with enzymes that are released during infections, allergic reactions, and asthma

describe agranulocytes

those white blood cells that simply lack any granules within their cytoplasm.

blood plasma

liquid portion of blood

blood serum

remaining fluid when blood clots and solids are removed

what is the difference between blood plasma and blood serum

blood serum is identical to plasma except for the absence of fibrinogen

name the plasma proteins

• albumins

• globulins

• fibrinogen

describe albumins

smallest and most abundant plasma protein

describe globulins

family of globular proteins that have higher molecular weights than albumins and are insoluble in pure water but dissolve in dilute salt solutions. Some globulins are produced in the liver, while others are made by the immune system.

describe fibrinogens

a protein produced in the liver that helps form blood clots to stop bleeding and heal wounds

define hematocrit

• measures the percentage of red blood cells in your blood

• centrifuge blood to separate component

what if leukocytes measure more than 1% of total blood volume, what would that indicate

you would assume there is an infection present

list the non protein components of the plasma

• nitrogenous compounds

• nutrients

• dissolved O2, CO2 and nitrogen

• electrolytes

name the electrolyte influences on blood volume/ pressure

Sodium and potassium are electrolytes that affect blood volume and pressure: 

• Sodium

  Helps control fluid levels and nerve and muscle function. Consuming too much sodium can raise blood pressure.

• Potassium

  Helps support heart, nerve, and muscle functions. It also moves nutrients into cells and waste products out of them. Consuming too little potassium can raise blood pressure.

define viscosity and how it relates to the blood

• resistance of fluid to flow, resulting from the cohesion of its particles

• whole blood is 4.5 to 5.5 times as viscous as water

• plasma is 2.0 times as viscous as water → important in circulatory function

define osmolarity and how it relates to the blood

• the total molarity of those dissolved particles that cannot pass through the blood vessel wall

• if too high blood absorbs too much water increasing the blood pressure

• if too low too much water stays in tissue, blood pressure drops and edema occurs

• optimum osmolarity is achieved by the body’s regulation of sodium ions, proteins and red blood cells

define hemopoiesis

• the production of blood cells and platelets, which occurs in the bone marrow.

• red bone marrow produces all seven formed elements

  • pluripotent stem cells (PPSC)

  • Colony forming unit

  • myeloid hemopoiesis

  • lymphoid hemopoiesis

when does a cell become committed

A cell becomes committed to division when it passes the G1 checkpoint and enters the S phase of the cell cycle. This checkpoint is also called the restriction checkpoint.

where are all sevem formed elements produced

red bone marrow

what does and erythrocyte contain

disc-shaped cell with a thick rim containing hemoglobin, an iron-rich protein that carries oxygen and carbon dioxide

what are the functions of the erythrocyte

• carry O2

• pick up CO2

• insufficient RBCs can cause death in minutes due to lack of O2 to tissues

why do women have lower red blood cell count

• androgen stimulates RBC production, women have lower testosterone levels

• women have periodic menstrual losses

• hematocrit is inversely proportional to the percentage of body fat and women tend to have a high body fat percentage compared to men

describe why hypoxemia occurs

• hypoxemia is low levels of O2

• a drop in RBC count often causes it

how does iron become absorbed through the gastrointestinal tract (what does it have go bind to)

• mixture of Fe 2+ and Fe3+ is ingested

• stomach acid converts Fe 3+ to Fe2+

• Fe2+ binds to gastroferritin

• gastroferriten transports Fe2+ to the small intestine and releases it for absorption

• in blood plasma Fe2_+ binds to transferrin

• in liver some transferrin releases Fe 2+ for storage

• Fe 2+ binds to apoferritin to be stored as ferritin

• remaining transferrin is distributed to other organs where Fe 2+ is used to make hemoglobin myoglobin, etc.

what occurs when the erythrocyte is at the end of its lifespan

Normal human red blood cells have an average life span of about 120 days in the circulation after which they are engulfed by macrophages. This is an extremely efficient process as macrophages phagocytose about 5 million erythrocytes every second without any significant release of hemoglobin in the circulation.

what is the byproduct of the breakdown of the erythrocyte

the non iron portion of heme is degraded into the waste product biliverdin which has a green pigment and then to another waste product bilirubin which has a yellow pigment and what make our urine yellow

what are the nutritional requirements for erythropoiesis

• vitamin B12 and folic acid

  • rapid cell division and DNA synthesis that occurs in erythropoiesis

• vitamin C and copper

  • cofactors for enzymes synthesizing hemoglobin

what stimulates erythropoiesis

• low levels if O2 (hypoxemia)

• high altitude

• increase in exercise

• loss of lung tissue in emphysema

what happens when iron is removed from heme, where does it go

• heme pigment converted to biliverdin (green)

• biliverdin converted to bilirubin (yellow)

• released into blood plasma (kidneys - yellow urine)

• liver removes bilirubin and secretes into bile

• concentrated in gallbladder: released into small intestine; bacteria create urobilinogen (brown feces)

describe the antigens of the blood

• complex molecules on the surface of the cells membrane that activate an immune response

• they are genetically unique to the individual

• used to distinguish self from foreign matter

• foreign antigens generate an immune response

• agglutinogens - antigens on the surface of the RBC that are the basis for blood typing

describe the antibodies of the blood

• protein (gamma globulins) secreted by plasma cells

• part of immune response to foreign matter \bind to antigens and mark them for destruction

• forms antigen-antibody complexes

• agglutinins - antibodies in the plasma that bring about transfusion mismatch

which blood type is the universal recipient

type AB

which blood type is the universal donor

type O

know what blood types are compatible

• type O recipient= O

• type B recipient = O,B

• type A recipient = O,A

• type AB recipient = O,A,B,AB

what occurs if the blood transfusion is not compatible

• donor RBC’s agglutinated by recipient plasma

• agglutinated RBCs block small vessels

describe the form and function of the leukocyte

• least abundant formed element

• protect against infectious microorganisms and other pathogens

• spend only a few hours in the bloodstream before migrating to connective tissue

• granules: all WBCs have lysosomes called non-specific granules

• granulocytes have specific granules that contain enzymes and other chemicals employed in defence against pathogens

list the leukocytes in order of quantity in the blood

• granulocytes

  • neutrophils (60-70%)

  • eosinophils (2-4%)

  • basophils (less than 1%)

• agranulocytes

  • lymphocytes (25 to 33%)

  • monocytes (3 to 8%)

describe the life cycle of the leukocyte

• leukopoiesis: production of WBC

• circulating WBCs do not stay in the bloodstream

• granulocytes leave in 8 hours and live 5 days longer

• monocytes leave in 20 hours transform into macrophages and live several years

• lymphocytes provide long-term immunity (decades) being continuously recycled from blood tissue fluid to lymph and back to the blood

define hemostasis

the cessation of bleeding stoping potentially fatal leaks

define the three hemostatic mechanisms

1. vascular spasm

2. platelet plug formation

3. blood clotting (coagulation)

what are platelets

• small fragments of megakaryocyte cells

• contain granules

• contains a complex internal structure and an open canalicular system

• amoeboid movement and phagocytosis

what are the functions of platelets

• secrete vasoconstriction that help reduce blood loss

• stick together to form platelet plugs to seal small breaks

• secrete procoagulants or clotting factors to promote clotting

• initiate of clot-dissolving enzyme

• chemically attract neutrophils and monocytes to sites of inflammation

• phagocytize and destroy bacteria

• secrete growth factors that stimulate mitosis to repair blood vessels

define clot retraction

• Clot retraction is when a blood clot shrinks in volume and expels serum after it forms. This process is a vital part of the body's natural healing response. 

• occurs within 30 minutes

• Platelet-derived growth factor (PDGF) secreted by platelets and endothelial cells

• mitotic stimulant for fibroblasts and smooth muscle to multiply and repair damaged vessel

define fibrinolysis

• dissolution of a clot

• factor XII speeds up the formation of kallikrein enzyme

• kallikrein converts plasminogen into plasma a fibrin dissolving enzyme that breaks up the clot

what occurs during blood clot dissolution

• positive feedback occurs

• plasmin helps dissolve fibrin

• The body senses that an injury has healed.

• The body releases an activator, such as tissue plasminogen activator (tPA), which turns on plasmin.

• Plasmin breaks down the clot's mesh-like structure.

• Blood flow is restored to the vessel.

how does the body prevent inappropriate clotting

• platelet repulsion

  • platelets do not adhere to prostacyclin coated endothelium

• thrombin dilution

  • by rapidly flowing blood, heart slowing in shock can result in clot formation

• natural anticoagulants

  • heparin interferes with formation of prothrombin activator

  • antithrombin deactivates thrombin before it can act on fibrinogen

pulmonary circuit

• right side of the heart

• carried blood to lungs for gas exchange and back to heart

systemic circuit

• left side of heart

• supplies blood to all tissues of the body and returns it to the heart

describe how/where blood travels through the heart in chronological order

Blood comes into the right atrium from the body, moves into the right ventricle and is pushed into the pulmonary arteries in the lungs. After picking up oxygen, the blood travels back to the heart through the pulmonary veins into the left atrium, to the left ventricle and out to the body's tissues through the aorta.

what are the major divisions of the circulatory system

1. pulmonary circuit

2. systemic circuit

define cardiovascular system

heart and blood vessels

define circulatory system

heart, blood vessels and the blood

list the layers of the heart wall

1. epicardium

2. myocardium

3. endocardium

list the chambers and locations of the heart

• right and left atria

• right and left ventricles

define right and left atria

• two superior chambers

• receive blood returning to heart

• auricles (seen on surface) enlarge chamber

define right and left ventricles

• two inferior chambers

• pump blood into arteries

list the valves in the heart

• pulmonary semilunar valve

• aortic semilunar valve

• aortic valve

• tricuspid valve

pulmonary semilunar valve location

in opening between right ventricle and pulmonary trunk

aortic semilunar valve location

in opening between left ventricle and aorta

aortic valve location

between left ventricle and aorta

tricuspid valve location

on the right side of the heart, between the right atrium and the right ventricle. 

what causes the valves to open and close

blood flow and pressure

describe the blood flow through the chambers when the ventricles relax

• pressure drops inside the ventricles

• semilunar valves close as blood attempts to back up into the ventricles from the vessels

• AV valves open

• blood flows from atria to ventricles

describe the blood flow through the chambers when the ventricles contract

• AV valves close as blood attempts to back up into the atria

• pressure rises inside of the ventricles

• semilunar valves open and blood flows into great vessels

describe how the flow of blood through the coronary arteries influences the contraction and relaxation of the heart

• 5% of the blood pumped by the heart is pumped to the heart itself through the coronary circulation to sustain its strenuous workload

• 250 mL of blood per minute

• needs abundant O2 and nutrients

describe the difference of the structures between the cardiac muscle cell and the skeletal muscle cell

• cardiac muscle cells are branched, contain intercalated discs connecting them to neighbouring cells, have a single nucleus centrally located, and are under involuntary control,

• while skeletal muscle cells are long, cylindrical, multinucleated, and are under voluntary control

define cardiocytes

striated short thick branched cells, one central nucleus surrounded by a light staining mass of glycogen

what are mechanical junctions

• tightly join cardiocytes

• fascia adheres

• desmosomes

what are electrical junctions

• gap junctions

• allow ions to flow between cells; can stimulate neighnours

what does cardiac muscle depend on to make ATP

aerobic respiration