All terms in this list:
Arteries: carry blood away from the heart
Veins: carry blood back to heart
Capillary Beds: in between arteries and veins
location of material exchange, between blood and interstitial fluid
Atria: left and right chambers receive blood from veins
receiving area of the heart
Valves: between atria and ventricles (atrial ventricular)
between ventricles and artery (lunar)
prevent backflow
Ventricles: push blood out of heart through arteries
shipping chambers of the heart
Steps of Pulmonary Circuit: 1. Blood flows from right atrium into right ventricle
2. Right ventricle pumps blood into pulmonary arteries. Branch into right and left lung and branch even more
3. At end of branches there are millions of pulmonary capillary beds. Carbon dioxide
Steps of Systemic Circuit: 1. Oxygenated blood in left atrium flows into left ventricle
2. Left ventricle pumps blood into aorta veins and branches into systemic arteries
3. At the end of systemic branches there are millions of systemic capillary beds
4. Oxygen can lea
Electrical Activity of Heart: Two sides of heart beat in unison
Heartbeat consists of two atria contracting together followed by 2 ventricles contracting together
3 Kinds of Cardiac Muscle Cells: pacemaker cell
conduction fibers
contractile cells
Pacemaker Cells: can fire action potentials spontaneuosly
critical regulatory cells
membrane potential does not sit still. once it reaches -70mv it begins depolarizing, then fires and then repolarizing.
Present in SA and AV nodes
Conduction Fibers: larger than normal cardiac cells
cells can transmit action potentials through jap junctions from cell to cell.
carry signal around the heart to tell cell its time to contract
fibers are shorted to each other
receive information from pacema
Contractile Cells: most numerous
get signal from other cells when its time to contract
generate force of heartbeat
within walls of ventricles
The Cardiac Cycle: 1. Pacemaker cells of node fire action potential. Synchronized and fire at once. Connected to conduction fibers which sends message to rest of heart. Makes it to contractile cells of right atria. Right and left atrium contract almost at the same time.
Diastole: relaxation
we usually focus on ventricular diastole
Systole: contraction
we usually focus on ventriular systole
Step 1 of Heartbeat Cycle: 1. Ventricular filling - early diastole
ventricles fill up with blood from veins
most blood flows in during mid to late diastole
higher pressure in veins pushes blood into ventricles
semilunar valves are closed. no blood flow between aorta
Step 2 of Heartbeat Cycle: 2. Isovolumetric contraction - early systole
ventricles begin to contract and pressure rises
AV valve shuts. not enough pressure to open semilunar valve. still higher pressure in aorta because of pressure from previous heartbeat
contracting ve
Step 3 of Heartbeat Cycle: 3. Ventricular Ejection - late systole
when pressure is great enough semilunar valve is pushed open and blood is pushed out from vent into aorta
Step 4 of Heartbeat Cycle: 4. Isovolumetric Relaxation - early diastole
ventricles begin to relax
semilunar valves close
Cardiac output =: heart rate x stroke volume
Cardiac Output at rest: 5 L/min = 72 b/min x 0.07 L/b
Cardiac Output Jogging: 11 L/min = 135 b/min x 0.08 L/b
Cardiac Output Sprint: 25 L/min = 190 b/min x 0.13 L/b
Control of Cardiac Output: Autonomic nervous system
medulla oblongata is in control, has cardiac center that integrates many different information about cardiac output and the emotional state of the animal
Sends info to heart through para and sympathetic nerves
Sympathe
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