unit one the heart Flashcards
The heart
a transport system consisting of two side by side pumps/chambers
what are the two different circuits and what are they for?
- pulmonary; lungs
- systemic; body
what are the characteristics of the pulmonary circuit?
- 1st side to pump blood
- right side
- decreases pressure
what are the characteristics of the systemic circuit?
- 2nd side
- left
- increases pressure
what is the cause/reason for movement in the heart?
pressure
where is the heart located?
mediastinum
Pericardium
double walled sac that surrounds the heart; made up of two layers
what are the two layers of the pericardium?
- fibrous (outer) pericardium
- serous (inner) pericardium
what are the two parts of the serous pericardium?
- parietal layer
- visceral layer (epicardium)
cardiac tamponade
- excess fluid that leaks into pericardial space
- can compress hearts pumping ability
what are the three layers of the heart wall?
(outer) -epicardium; visceral -myocardium; muscle -endocardium, SS epi. (inner)
atria
thin walled chambers, propulsion of blood
auricles
expanded part of atria’s to fit more blood
right atrium
receives deoxygenated blood from body
(veins) superior/ inferior vena cava and coronary sinus
left atrium
receives deoxygenated blood from the lungs
four pulmonary veins
valves
ensure blood flow through the heart in response to pressure
what are the two major types of valves and their corresponding valves?
- atrioventricular
- tricuspid (RA/V)
- bicuspid (mitral) (LA/V) - semilunar
- pulmonary SL (RV/PA)
- aortic SL (LV/AA)
coronary circulation
functional blood supply to heart muscle itself when heart is relaxed
coronary sinus
empties into right atrium
- great cardiac vein
- middle cardiac vein
- small cardiac vein
intercalated discs
-desmosomes; hold cell together
-gap junctions; allow ions to pass from cell to cell
functional syncytium
skeletal and cardiac muscle differences
- pacemaker cells; automatic
- contracts as a unit
- extracellular
- tetanic dosent occur
- relies on aerobic respiration
what are the three parts of action potential?
- pacemaker potential- k is closed, but na open
- depolarization- ca open
- repolarization- k opens
what are the 5 parts of the electrical activity in the heart?
- Sinoatrial node
- atrioventricular node
- atrioventricular bundle
- R/L bundle branches
- purkinje fibers
what is included in sympathetic
norepinephrine, Na+
