Chapter 5 Flashcards
Tributaries of SVC
External jugular veins Internal jugular veins Subclavian veins Brachiocephalic veins Posterior intercostal veins Azygos vein
Fetus and placenta
Thymus Placenta Umbilical cord Umbilical arteries Umbilical vein
Branches of aortic arch
Brachiocephalic artery
Common carotid arteries
Subclavian arteries
Branches of thoracic aorta:
Posterior intercostal arteries
Respiratory and Digestive Structures:
Trachea Main bronchi Lungs Secondary bronchi Pleurae Esophagus
lungs
- Apex
- Base
- Root
Pleurae
Parietal pleurae
Visercal pleurae
Pleural cavities
Nerves
Vagus nerves
Phrenic nerves
Sympathetic trunk ganglion
left recurrent laryngeal nerve
branches off the vagus nerve
major vasculature in the thoracic cavity
superior vena cava (SVC), inferior vena cava (IVC), aortic arch, brachiocephalic trunk, common carotids, subclavian arteries, subclavian veins, and azygos vein.
venous blood
deoxygenated blood is brought TO the heart
arterial blood
oxygenated blood flow AWAY from heart
heart and lungs
2 important organs that help sustain life and propel “life fluid”, or oxygenated blood throughout the body
intrinsic conduction system
how blood flows through the heart, cardia output and stroke volume, and neural and hormonal inputs
function of heart
pump deoxygenated blood to the lungs, and oxygenated blood to the rest of the body
right and left coronary artieries
bring oxygenated blood from the aorta and bran into the right & left sides of the cardiac muscle
blood transfuses through
the myocardium, and then the venous blood drains into the the coronary sinus and dumps into the right atrium to join the rest of the deoxygenated blood
neural input, hormonal signals, and intrinsic conduction system
control the rhythm of the heart contractions
with no neural input or hormones to affect sinus rhythm
the heart would beat an average of 100 beats per minute
how is it that the heart can generate its own sinus rhythm without neural stimulation?
it contains cells with an “unstable resting potential”, called cardiac pacemaker cells
cardiac pacemaker cells
aka autorhythmic cells
3 phases of action potential to initiate heart contractions
1) pacemaker potential
2) depolarization
3) repolarization
pacemaker potential
there is a slow opening of Na+ channels, while the K+ channels are closing, thus becoming more positive, initating action potential and entering the depolarization phase
membrane potential
~40mV, depolarization has began
Depolarization
Ca2+ channels open, causing increase in positivity, thus a peak, that is short lived (bc excitable cells)
Repolarization
membrane potential becomes more negative, the K+ channels open, allowing K+ to exit out of the cell.
Cycle begins again
when K+ channels begin to close, and Na+ channels begin to open again
Major concentration site of pacemaker cells
SA (sinoatrial) node, located in the right atrium
SA Node
is where sinus rhythm is established, it is the determinant of heart rate
Internodal path
within right atrium, that connects the SA node to the AV (atrioventricular) node
Impulse of the AP is carried along the internodal path
and pauses for 0.1 seconds at the AV nose, this allows the atria to contract, forcing blood into the ventricles
Impulse is then continued towards the AV node to the
bundle of HIS, located in the superior portion of the interventricular septum