Week 13 Flashcards
What is the function of the figure 8 pattern in the heart?
- used to pump the blood
- one located in the atria; one in the ventricle
Difference in the ventricular muscle thickness
- right side is thin (goes to lungs)
- left side is thick (pumps to body)
-doing a lot more work, needs to be thicker
Function of valves
keeps blood from going backward
Septum
divides the heart into chambers
Interatrial Septum
in between the atrium
interventricular septum
between the ventricles
AV Valves
- Tricuspis
- Bicuspid (mitral)
Semilunar Valves
- Aortic
- Pulmonary
Chordae tendinae
connects flaps of valves to papillary muscles
papillary muscles
prevents backflow to generate tension in chordae tendinae
- prevents valves from moving backwards
Steps of blood flow
Step One:
1. Atria contact
2. AV valves open (blood going to ventricles)
3. Semilunar valves close (keeps blood from going back
Step Two:
1. ventricles contract
2. AV valves close
3. Semilunar Valve open (blood going to lungs/body)
Difference between skeletal and cardiac muscle
- Autorhythmicity
- Intercalated Disc
- Only uses oxygen
Autorhythmicity
- heart will beat on its own
-has its own rhythm; makes its own action potential
What is intercalated disc made of?
- Gap Junctions
- Desmosomes
Gap Junctions
-spaces in membrane between cells so they can share sarcoplasm
-between cardiac muscles
- direct electrical connections (no synapse)
Desmosomes
-sticks cells together
-allows them to fire together
Sinoatrial Node (SA Node)
- sets the rhythm of the heart (AP)
Sinus Rhythm
-normal heart beat
-60-72 average
Tachycardia
HR higher than 100 bpm
Bradycardia
HR lower than 60 bpm
How does the “LUB DUB” sound of the heart work?
- First sound “LUB”
-Step 2 of blood flow
-ventricular muscle contracts; AV valves close - Second Sound “DUB”
-Step 1 of blood flow
-Semilunar valves close
Atrioventricular Valve (AV Valve)
-between atrium & ventricle
-relay station (relays signal)
-allows for signal pause to let atria completely empty of blood
2 Circuits of the Body
- Pulmonary Circuit
- Systemic Circuit
Pulmonary Circuit
-Lung circuit
-pulmonary artery/vein
-goes to left atria
-
Systemic Circuit
-body circuit
-aorta- majority sends to the body
capillaries
site of exchange of nutrients and oxygen
structure of capillaries
-simple epithelial
Lumen
-big hole in artery and vein, where the blood is
Vasocontriction
lumen gets smaller
ex. outside in the winter, the blood wants to stay warm
vasodilation
lumen gets bigger
Artery
carries oxygenated blood AWAY from the heart
Veins
carries deoxygenated blood TO the heart
Function of valves
-blood can only go in one direction
-stops blood from going backward
Tunica Media
-where the thick muscle is located in artery
Function of heart muscle
-pump blood from veins back to where it needs to be
-carries blood back to heart
Osmotic Pressure
pressure drawing fluid into blood
Aorta
-main artery that carries blood away from the heart to the rest of the body
Coronary Artery
supplies the oxygen to blood to feed the heart
Coronary Sinus
responsible for draining deoxygenated blood from myocardium
Major Veins
-vena cava
-pulmonary vein
-coronary sinus
-jugular vein
jugular vein
takes blood away
Major Arteries
-aorta
-pulmonary
-coronary
-carotid (head)
Osmotic Pressure
pressure drawing fluid INTO the blood
Hydrostatic Pressure
pressure pushing fluid OUT of capillary
2 Sides of the capillary
- Artery Side
- Vein Side
Artery Side of capillary
-hydrostatic pressure is higher than osmotic pressure
-fluid will be pushed OUT of the tissues
Vein Side of capillary
-osmotic pressure is higher than hydrostatic pressure
-fluid is brought back into capillaries and brought back to the heart
Albumin
key protein that drives osmotic pressure
