Chapter 18 Flashcards
enclosed and held by pericardium
heart covering
sinoatrial node (SA node)
- mass of cells in right atrium opening the superior vena cava
- sents impluses to artial muscles for atrial contractions
- stimulates AV node
- SA is pace maker
final 0.4 sec
all chamber relax
next 0.3 sec
- ventricles contract (systole)
- atria relax (diastole)
left ventricle pumps oxygenated blood into the — that is divided into — to deliver oxygenated blood to major organs
aorta; major arteries
right coronary is divided into
posterior interventricular branch and marginal branch
from the upper body
superior vena cava
* deoxygenated blood only
timing
- 75 heart beats per minute (average)
- 1 heart beat= 1 cardiac cycle
- each cycle is about 0.08 sec= divided into 0.1 + 0.3 + 0.4 sec
aortic semilunar valve
- located between the left ventricle and aorta
- 3 flaps
- attached to wall of aorta
- open inside the aorta
- oxygenated blood flow in one direction only
comb like muscle projections on the inner wall of the
atria that provide rigidity to the atrial wall
pectinate muscles
left coronary is divided into
anterior interventricular branch and circumflex branch
pulmonary trunk is divided into – and —— that delivers blood to the – and — for oxygentation
left and right pulmonary arteries; left and righ lungs
ventricular diastole
- presurre drops
- semilunar valves close
- takes 0.05 sec
- is isovolumetric relaxation
leads to heart block and cardiac arrest
hyperkalemia (high blood potassium level)
pericardium has 2 parts
- fibrous pericardium
- serous pericardium
right atrium then delivers deoxygenated blood to the –
right ventricle
thicker than the atrial wall
ventricular wall
is an oval depression on the septal wall of the right atrium
fossa ovalis
is created when the atrioventricular valves close
lubb
endocardium
- thin layer of fibrous connective tissue
- lines heart muscle and heart valves
two atria are separated by ____
interatrial septum
that supply blood to the wall
of the left ventricle
anterior interventricular branch
valves of the heart
- two atrioventricular valves (tricuspid and bicuspid/mitral)
- two semilunar valves (aortic and pulmonary)
right atrium recieves deoxygenated blood through
- superior vena cava
- inferior vena cava
- coronary sinus
ventricles receive atrial blood
ventriclar filling
reduced ionic calcium depresses the heart
hypocalcemia
right ventricle delivers deoxygenated blood to the–
pulmonary trunk
that supply blood to the wall
of the right ventricle
posterior interventricular branch
dramatically increases heart irritability and leads to convulsive contractions
hypercalcemia
entire heart muscle behave as a single unit
functional syncytium
two ventricle are separated by ____
interventrucular septum
deoxygenated blood is collected by –
coronary sinus
heart wall two layers of tissue
- myocardium
- endocardium
that drains posterior part of the heart wall
middle cardiac vein
is the phase of relaxation
diastole
is an opening in the interatrial septum of the fetal heart – that
corresponds to the site of fossa ovalis
foramen ovale
the space between the parietal and visceral layers; contains pericardial fluid
pericardial cavity
* serous pericardium
irregular muscular columns projected from the inner
surface of the right ventricle of the heart
trabeculae carneae
is the phase of contraction
systole
heart sound
- lubb and dupp
- lubb is louder and longer than the dupp
heart rate less than 60 beats/min
bradycardia
finger like muscle projections inside the ventricles
papillary muscles
oxygenated blood from the lungs is delivered to the left atrium
through
pulmonary veins
thicker than the right ventricular wall
left ventricular wall
pumonary semilunar valve
- located between right ventricle and pulmonary trunk
- 3 flaps
- attached to wall of pulmonary trunk
- open inside pulmonary trunk
- deoxygenated blood flow in one direction only
blocks heart contraction by
inhibiting calcium ion transport
hypernatremia (high blood sodium level)
impluses are sent by a bundle of nerve fibers called the —
bundle of his (atrioventricular bundle)
oxgenated blood is supplied by — and —
right and left coronary arteries
from heart muscles
coronary sinus
* deoxygenated blood from heart
tricuspid valve
- 3 flaps
- valves are connected to the papillary muscles of the right ventricle by chordae tendineae (fibrous tissue)
myocardium
- cardiac muscle
- many layers, involuntary
from the lower body
inferior vena cava
* deoxygenated blood only
heart muscle are stimulated by nerves
self-excitable
outer thicker layer if fibrous tissue
fibrous pericardium
serous pericardium
- divided into parietal (outer) and visceral (inner) layers
first 0.1 sec
- atria contract (systole)
- ventricle relax (diastole)
that supply blood to the wall of the left atrium and left ventricle
circumflex branch
that the anterior part of the heart wall
great cardiac vein
that supply blood to the wall of the right ventricle
marginal branch
heart rate over 100 beats/min
tachycardia
biscuspid valve
- also known as mitral valve
- 2 flaps
- valves are connected to the papillary muscles of the left ventricle by chordae tendineae
is created when the semilunar valves close
dubb
pathway of blood through the heart and lungs
right atrium → tricuspid valve → right ventricle → pulmonary semulunar valve → pulmonary arteries → lungs → pulmonary veins → left artium → bicuspid valve → left ventricle → aortic semilunar valve → aorta → systemic circulation
ventricular systole
- atrioventricular valves close
- ventricles contract
- first 0.05 sec is isovolmetic contraction period
- semilunar valves open up; ejection period (0.25 sec)
- ventricles pump 1/2 blood content= stroke volume
is the systole and diastole of the atria and the ventricles
complete cardiac cycle
heart has 4 chambers
right atrium (superior), left atrium (superior), right ventricle (inferior), and left ventricle (inferior)
atrial systole
- 70% artial blood flow to ventricles when artioventricular valves are open
- 30% artial blood flow under atrial contraction
