Anatomy Test 2

what happens during coagulation?

fibrin forms a mesh that traps red blood cells and platelets, forming the clot

clot that develops and persists in unbroken blood vessel (may block circulation leading to tissue death)

thrombus

a thrombus freely floating in the blood stream

embolus

embolus obstructing a vessel (pulmonary and cerebral emboli)

embolism

aspirin, heparin, warfarin, dabigatran are \_______________ drugs

anticoagulant

What is deep vein thrombosis?

Thrombosis forming in the deep veins, generally of the lower extremities. Many are asymptomatic but classical symptoms include swelling of the leg, tenderness of the calf, increased warmth and pain on passive dorsiflexion.

(heart attack) chest pain which radiates into left shoulder and arm, leading cause of death in high or middle-income countries

myocardial infarction (MI)

how is platelet adhesion prevented?

-by smooth endothelium of blood vessels prevents platelets from clingling
-antithrombic substances nitric oxide and prostacyclin secreted by endothelial cells
-vitamin E quinone acts as potent anticoagulant

what is the circulation of blood?

-right atrium
-right ventricle
-pulmonary circuit
-systemic circuit
-left atrium
-left ventricle

Why do arteries have thick walls?

To withstand the high pressure within them

What are sphincters?

muscles that control the passage of material from one organ to the next

when sphincter are open...

blood flows through true capillaries

when sphincters are closed...

blood flows through metarteriole thoroughfare channel and bypasses true capillaries

least permeable and most common (skin, muscle)

continuous capillary

large fenestrations (pores) increase permeability. occurs in areas of active absorption of filtration (kidney, small intestine)

fenestrated capillary

most permeable. occurs in special locations (liver, bone marrow, spleen)

sinusoid capillary

What is blood pressure?

force of blood against arterial walls

Tetralogy of Fallot results in low oxygenation of blood due to the mixing of oxygenated and deoxygenated blood in the left ventricle

Blue Baby syndrome

Where is the heart?

in mediastinum between second rib and fifth intercostal space; two thirds of the heart to the left of midsternal line

point of maximum impulse (PMI) palpated between fifth and sixth ribs, just below left nipple

apical impulse

Is the heart symmetrical?

no

the \_______ of the heart leans toward right shoulder

base

the \_____ of the heart points toward the left hip

apex

What are the 4 chambers of the heart?

right atrium, right ventricle, left atrium, left ventricle

why is the heart surrounded with fat?

to cushion and protect it

what supplies the heart with energy and oxygen?

coronary arteries

-main blood supply to heart/crown artery
-supplies right atrium and most of right ventricle

right coronary artery

what happens in a heart attack?

-When a blod clot blocks the flow oxygen-rich blood to the cardiac muscle
-plaque builds up in the artery

The heart is enclosed in a double-walled sac called the \___________

pericardium

what is the purpose of the pericardium?

it protects, anchors to surrounding structures, and prevents overfilling

\_______________ lines internal surface of fibrous pericardium

parietal layer

\________________ on external surface of heart

visceral layer (epicardium)

two layers (the parietal layer and visceral layer) is separated by fluid-filled \____________ (decreases friction)

pericardial cavity

inflammation of pericardium roughens membrane surfaces; pericardial friction rub (creaking sound) heard with stethoscope; cardiac tamponade; excess fluid sometimes compresses heart; limited pumping ability

pericarditis

too much friction between visceral pericardium and parietal pericardium leads to...

pericarditis

the visceral layer of serous membrane on the heart

epicardium

-the actual heart muscle
-spiral bundles of contractile cardiac muscle cells
-cardiac skeleton: crisscrossing, interlacing layer of connective tissue
-anchors cardiac muscle fibers
-supports great vessels and valves
-limits spread of action potentials to specific paths

myocardium

-the innermost layer of tissue that lines the chambers of the heart
-embryological similar to the endothelial cells that line blood vessels

endocardium

right side recieves oxygen-poor blood tissues; pumps to lungs to get rid of CO2, pick up O2

pulmonary circuit

left side recieves oxygenated blood from lungs; pumps to body tissues

systemic circuit

the recieving chamber of the heart

atria

recieves blood returning from systemic circuit

right atrium

receives blood returning from pulmonary circuit

left atrium

the pumping chambers of the heart

ventricles

pumps bloof through pulmonary circuit

right ventricle

pumps blood though systemic circuit

left ventricle

\___________ make sure blood flows in one direction

heart valves

separates atria

interatrial septum

separates ventricles

interventricular septum

remnant of foramen ovale of fetal heart

fossa ovalis

valve between the right atrium and the right ventricle

tricuspid valve

valve between the left atrium and the left ventricle.

mitral (bicuspid) valve

The semilunar valve separating the aorta from the left ventricle that prevents blood from flowing back into the left ventricle.

aortic valve

Appendages that increase atrial volume

auricles

\___________ atrium with pectinate muscles

right

\_______ atrium with pectinate muscles only in auricles

left

A vein that is the second largest vein in the human body and returns blood to the right atrium of the heart from the upper half of the body.

superior vena cava

A vein that is the largest vein in the human body and returns blood to the right atrium of the heart from bodily parts below the diaphragm.

inferior vena cava

enlarged vessel on the posterior aspect of the heart that empties blood into the right atrium

coronary sinus

\________ pulmonary veins empty into left atrium

four

\_______ are the pumping chambers

ventricles

\________ are thicker walls than atria and are actual pumps of the heart

ventricles

What 3 veins empty into the right atrium?

superior vena cava, inferior vena cava, coronary sinus

\________ ventricle pumps blood into the pulmonary trunk

right

\______ ventricle pumps blood into arota (largest artery in the body)

left

what is the largest artery in the body?

aorta

What ensures unidirectional blood flow through the heart?

heart valves

Heart valves open and close in response to \__________.

pressure changes

What are the two atrioventricular valves?

tricuspid and bicuspid

what is the right AV valve?

tricuspid valve

What is the left AV valve called?

bicuspid (or mitral valve)

the \___________________ anchors cusps to papillary muscles and hold valve flaps in closed posotion

chordae tendineae

What do the semilunar valves do?

prevent backflow into ventricles when ventricles relax

how do semilunar valves open and close?

in response to pressure changes

what are the two semilunar (SL) valves?

aortic semilunar valve and pulmonary semilunar valve

How many pulmonary veins are there?

4 (2 on each side)

\___________ volumes of blood is pumped to pulomonary and systemic circuits

equal

pulomary circuit is \_____, and \____________ circulation

short, low-pressure

systemic circuit \_______, \____________ circulation

long, high-friction

the \____________ ventricle walls is 3x thicker than right as it pumps with greater pressure

left

characteristics of cardiac muscle:

-strated, cylindrical, branched, uninucleated fibers
-only in heart
-involutary
-has intercalated discs

what is the purpose of intercalated discs?

-Enable the cells to transmit impulses rapidly so that the whole structure contracts as a unit.
-holds cells together when heart beats

\_______________________ connect individual cardiac muscle cells

intercalated disc

\___________ prevent cells from separating during contraction (proteins in cell membrane)

desmosomes

\__________ allow ions to pass from cell to cell; electrically couple adjacent cells. allows heart to be functional syncytium

gap juntions

What does the SA (sinoatrial) node do?

Sends out impulses that make the heart contract, autorhymia (pacemaker)

What does the AV (atrioventricular) node do?

sends impulse thru bundle of His \> passes between both ventricles \> branches into ventricles via purkinje fibres which result in contraction

Steps of electrical conduction in the heart

1) The sinoatrial (SA) nose (pacemaker) generates impulses
2) The impulses pause (0.1 s) ar the atrioventricular (AV) node
3) The atrioventricular (AV) bundle connects the atria to the ventricles
4) The bundle branches conduct the umpulses through the interventricular septum.
5) The subendocardial conducting network depolarizes the contractile cells of both ventricles.

what is a normal heart beat?

60-100 bpm

What is the QRS complex?

ventricular depolarization and atrial repolarization

the "backup generator" a secondary autorythmic region; it delays impulses by approximately 0.12 s

atrioventricular node (AV node)

is specialized for electrical conduction from the AV node to the apex

Bundle of His

are cardiomyocytes specialized for rapid conduction to facilitate synnchronized ventricular contractions

purkinje fibers

what does aV stand for?

augmented vector

What is an EKG/ECG?

Electrocardiogram
A graphic recording of electrical activity in the heart

What is a 3-lead EKG?

the sum of all potentials

the \_______ is a composite trace summing all electrical conduction

EKG

atrial depolarization

P wave

ventricular depolarization

Q wave

ventricular contraction

QRS complex