Day 2 (cardiovascular) Flashcards
Where is the heart placed?
mediastinum
What are the surfaces of the heart?
sternocostal surface (front)
base (back)
diaphragmatic (bottom)
Circulation types:
pulmonary (lungs)
systemic (rest of body)
coronary (heart)
Type of blood:
right side (deoxygenated)
left side (oxygenated)
right atrium:
deoxy blood from superior vena cava, inferior vena cava and coronary sinus
rough wall (pectinate muscles)
contains fossa ovalis (hold in heart from when in womb)
has tricuspid valve (between right atria and ventricle)
right ventricle:
receives deoxy blood from right atrium
tricuspid valve is connected to chordae tendineae (heart strings)
has pulmonary valve, leading to pulmonary artery
left atrium:
receives oxy blood from 4 pulmonary veins
contains bicuspid valve (between left atrium and ventricle)
left ventricle:
receives oxy blood from left atrium, passes through bicuspid valve
bicuspid valve is connected to chordae tendineae (heart strings)
valves:
atrioventricular valve: tricuspid and bicuspid
semilunar valve: aorta and pulmonary
what is the pericardium?
membrane that surrounds and protects the heart
anchors heart to surrounding structures
what are the layers of the pericardium?
fibrous: outer layers
-prevents overdistention
serous: inner layer
-encloses pericardial cavity which contains pericardial fluid (lube= prevents friction)
3 layers to heart wall:
endocardium (inner layer)
-reduce turbulence, lines chambers and valves
myocardium (middle layer)
-muscle (pump heart)
epicardium (outer layer)
-connects serous membrane of the pericardium
systolic
heart contract
left ventricle contract, blood forced into aorta= systolic BP
diastolic
heart relaxes
ejection of blood, pressure in arteries= diastolic BP
pathway of blood:
1) SVC, IVC and coronary sinus return deoxy blood to RA
2) deoxy blood travels from RA to RV through tricuspid valve
3) tricuspid valve close :prevent backflow of blood into RA
4) deoxy blood travels from RV to Pulmonary trunk through pulmonary valve
5) pulmonary valve closes to prevent backflow of blood into RV
6) pulmonary trunk splits into two pulmonary arteries
7) deoxy blood travels via pulmonary arteries to the lungs to be oxygenated at the pulmonary capillaries
8) oxy blood returns to LA via pulmonary veins (4)
9) oxy blood travels from LA to LV via bicuspid valve
10) bicuspid valve closes to prevent backflow of blood into LA
11) oxy blood travels from LV into aorta via aortic valve
12) aortic valve closes to prevent backflow of blood into LV
13) oxy blood travels in aorta into systemic circulation
coronary circulation:
heart has it own circulation of oxy blood
originates from aorta and encircles heart, filling with blood in diastolic phase
venous return via coronary sinus into RA
Right coronary artery (RCA)
gives blood to right atrium then goes round the back to both ventricles
front= right marginal artery
back= posterior interventricular artery
Left coronary artery (LCA)
gives blood to pulmonary trunk then splits:
circumflex artery goes all the way round the heart
anterior interventricular artery
left marginal artery
portal circulation:
blood to and from liver
hepatic artery carries oxy blood
hepatic portal vein carries rich in nutrients blood from GI tract
blood returns to heart from liver via IVC
conduction system:
Sinoatrial node (SAN): heart pacemaker, conduction begins, positioned near RA/ VC
electrical impulse spreads across atria, causes atrial contraction
impulse arrives at atrioventricular node (AVN)
impulse is delayed to allow filling of blood in ventricles
impulse progresses to Bundle of His in the septum
Bundle of His separates into left and right bundle branches
bundle branches divide into Purkinje fibres, which spread over ventricles allowing ventricular contraction
ECG
P wave: atrial depolarisation
QRS complex: ventricular depolarisation
T wave: ventricular repolarisation
Blood Pressure (BP):
pressure in which blood exerts on the blood vessel wall
BP= Cardiac Output
———————–
Total Peripheral Resistance
BP= systolic (120)
——————–
diastolic (80)
Cardiac Output (CO)
CO= Amount of blood ejected from LEFT VENTRICLE into the aorta PER MINUTE
CO= Heart Rate (bpm) x Stroke Volume
Stroke Volume- amount of blood pumped by LEFT VENTRICLE during EACH BEAT
Peripheral Resistance
resistance of a blood vessel
smooth muscle either relaxes (decrease pressure) or constricts (increase pressure) in response to stimulations
