physiology chap 13

what are the functions of the circulatory system

transport, regulation, protection

what is being transported in circulatory system

Gases Nutrients Waste

what is being regulated in the circulatory system

Hormonal, Thermoregulation

what is being protected in circulatory system

Immunity, Clotting

Components of the Circulatory System

Cardiovascular system, lymphatic system

what does the cardiovascular system contain

Blood Blood vessels Heart

what does the lymphatic system contain

Lymphatic vessels Lymph Lymph nodes

Plasma definition

Liquid portion accounting for 55% of blood

what does plasma contain

dissolved substances (such as various ions, metabolites, etc.) and proteins

Albumins

maintains osmotic pressure

Globulins

transports various substances

Fibrinogen

blood clotting

Formed elements

Account for 45% of whole blood

what do the formed elements contain

Erythrocytes, leuokocytes, Thrombocytes

erythrocytes

red blood cells

leukocytes

white blood cells

thrombocytes

platelets

erythrocytes have no what

nucleus or mitochondria

how long do erythrocytes survive

about 120 days

erythrocytes function

carrying gases

Hemoglobin = Composed of

of 4 polypeptide chains (globins) and 4 iron-containing heme groups

Heme transports what

O2

Globins carry what

CO2

Leukocytes Able to leave the circulation (diapedesis) and move to areas

of need (amoeboid motion)

Eosinophils

Function to reduce inflammation response and fight parasitic invasion

Basophils

Function to mediate the inflammation response (histamines) and to prevent blood clots (heparin)

Neutrophils

First line of defense in a bacterial invasion

Cell fragments pinched off from

megakaryocytes

where are cell fragments pinched off from megakaryocytes

red bone marrow

why are platelets important

preventing blood loss

Hematopoiesis

Production of blood cells

Erythropoiesis

production of RBCs

what is Erythropoiesis stimulated by

by erythropoietin from the kidneys and the liver when PO2 in blood decreases

Leukopoiesis

Production of WBCs

How is Leukopoiesis stimulated

various cytokines, which are produced by WBCs or by invaded tissue

Platelet production is regulated by

thrombopoietin

Antibodies can bind

antigens, resulting in agglutination (clumping) or hemolysis (rupture) of RBCs

what blood type is the universal recipient

Type AB

which type is the universal donor

Type O

Mixing unmatched blood (i.e. type A with type B) causes what

agglutination of the RBCs

What does RH typing determine

the presence of the Rh antigen

what if the person has rh antigen

the person is Rh positive (Rh+)

An Rh- mother having an Rh+ child could create

a negative reaction in subsequent births

Hemostasis

stoppage of bleeding

what are the 3 stages of hemostasis

vasospasm, platelet plug formation, coagulation or blood clotting

Vasospasm (vasoconstriction)

chemicals released from the sight of injury

Platelet plug formation due to

exposed collagen fibers from damaged blood vessel

Coagulation or Blood clotting

fibrin clot

Formation of fibrin clot =

fibrinogen converts to fibrin forming a net that entraps RBC

what are the 2 clotting pathways

extrinsic and intrinsic

extrinsic

initiated by release of tissue factor

intrinsic

initiated by contact with collagen

Fibrinolysis

Dissolution of clot requires plasmin

how is the heart divided

into right and left halves by the septum

each half of the heart has what

one atrium and one ventricle

what are the 2 circuits of the heart

pulmonary and systemic

how many valve types are there

2

where Atrioventricular (AV) valves are located

between atria and ventricles

Right av valve is called what

tricuspid valve

left av valve is called what

bicuspid valve

Semilunar valves are at the base of

the aorta and pulmonary trunk

left aortic semilunar valve is called what

aortic semilunar valve

right semilunar valve is called what

pulmonary semilunar valve

what is the first heart sound from

closing of the AV valves

what is the 2nd heart sound from

semilunar valves closing

Heart is two pumps that work

together, right and left half

Repetitive contraction is what

systole

relaxation is what

dystole

Blood moves through circulatory system from what concentration

high to low pressure

Because of intercalated discs between cardiac muscle cells they create a

functional syncytium

The functional syncytium allows

a single impulse to stimulate the cardiac cycle

The automatic nature of the heart is referred to as

automaticity

SA node (sinoatrial node):

pacemaker that generates spontaneous action potentials.

AV node (atrioventricular node):

action potentials conducted more slowly here

AV bundle

action potential reaches interventricular septum

Right and left bundle branches: extend to

right and left ventricles

Purkinje fibers

Large diameter cardiac muscle cells

The pacemaker potential

Spontaneous depolarization (autorhythmicity)

During the electricity of the heart which polarization occurs

hyperpolarization

during electricity of the heart Hyperpolarization causes Na+/K+ channels (HCN channels) to open until

threshold is reached

during electricity of the heart Hyperpolarization causes which channels to open Na+/K+ channels (HCN channels) to open until

Na+/K+ channels

At -40mV which channels open

Ca2+ channels open

Depolarization phase which channels open

Na+ channels

during depolarization phase what channels close

K+ are closed

during the depolarization phase

what voltage gated channels open

during Repolarization phase what Voltage-gated channels close

Na+ channels close

during repolarization phase what do some channels open

voltage-gated K⁺ channels open

during Repolarization phase what channels open

Ca2+ channels

in the Final repolarization phase what channels close

Voltage-gated Ca2+

in the final repolarization phase which channels open

voltage-gated K+ channels

Absolute refractory period

Cardiac muscle cell completely insensitive to further stimulation

Relative refractory period

Cell exhibits reduced sensitivity to additional stimulation

Long refractory period prevents

tetanic contractions

Atherosclerosis

a buildup of plaque on the vessel wall which can create thrombi or occlude the vessel

Ischemic heart disease

deficient oxygen supply due to inadequate blood flow

Angina pectoris

build up of lactic acid can cause pain

Myocardial infarction (MI)

necrosis of myocardial cells

Bradycardia

a rate of < 60 bpm

Tachycardia

a rate >100 bpm

Mitral stenosis

thickening and calcification of mitral valve