L12- Circulatory (test 3) Flashcards
What are the two circulatory systems and what can be found in each?
- Cardiovascular system
- heart, blood vessels, blood - Lymphatic system
- lymphatic vessels, lymph fluid, cells/tissues/organs
What are the functions of the vascular systems (CVS & LS)
- Transportation to/from cells
- respiratory/ gases (CVS)
- digestive/nutrients (CVS/LS)
- urinary/ wastes CVS) - Regulation
- Endocrine/hormones (CVS)
- Skin/ Temperature (CVS) - Protection
- clotting (CVS)
_ immunity (CVS/LS)
What are the two circuits found within the cardiovascular system?
Pulmonary circuit & systemic circuit
From what circuit of the cardiovascular system is oxygenated blood pumped? Deoxygenated blood?
Oxygenated blood = systemic circuit
Deoxygenated blood = pulmonary circuit
What side of the heart pumps blood to the lungs? All body tissues?
Lungs = right (pulmonary circuit)
Entire body = left (systemic circuit)
Veins
Carry blood to the heart
Arteries
from the heart to organs
In the pulmonary circuit, veins carry oxygenated or deoxygenated blood? What about arteries?
Veins - oxygenated blood
Arteries - deoxygenated
In the systemic circuit do veins carry oxygenated or deoxygenated blood? What about arteries?
Arteries = oxygenated blood
Veins = deoxygenated
What are the four chambers of the heart?
Right atrium, right ventricle, left atrium, left ventricle
What are the great vessels of the heart?
- superior/inferior vena cava
- pulmonary trunk
- aorta
- pulmonary veins
What are the two atrioventricular valves (AV)
Right AV valve - tricuspid
Left AV valve - bicuspid
What are the two semilunar valves (SL)
- Pulmonary SL valve
- Aortic SL valve
The valves in the heart are muscle tissue
TRUE or FALSE
False - valves are fibrous tissue
Valves function is to
Prevent back flow of blood
What is the function of the pulmonary muscles & chordae tendineae in the heart?
Prevent AV valves from prolapsing / back flow of blood
What is a a heart murmur?
Abnormal sound of the heart, due to back flow of blood
What creates the 1st heart sound “Lub”? What about the 2nd heart sound “Dub”
Lub = Atrioventricular valves (AV) valves closing
Dub = Semilunar (SL) valves closing
Right v.s left ventricles
Right
- thin wall
- weak pump = generating low pressure
Left
- thick wall
- strong pump = generating high pressure
What is the pressure for the left and right ventricle?
Left ventricle = 120/80
Right ventricle = 25/8
Coronary arteries
Hearts own blood supply
Function of coronary arteries
Deliver blood to heart muscle cells during ventricular Relaxaction (diastole)
What happens when a coronary arteries are blocked?
Causes a heart attack
The cardiac cycle is..
Repeating pattern of heart contraction and relaxation
Mechanical components function of the cardiac cycle
Pump blood through pulmonary and systemic circuit
Electrical component function of the cardiac cycle
- stimulates muscle cell contraction
- creates coordinated and rhythmic contractions of the atria and ventricles
Systole
Heart muscles contract (blood ejection)
Diastole
Heart muscle relaxation (blood filling)
What are the 5 phases of the cardiac cycle?
- Isovolumetric contraction
- Ejection
- Isovolumetric relaxation
- Rapid filling
- Atrial contraction
Isovolumetric contraction
Atria relaxed
SL valves closed
Ventricles contract
- ventricle pressure > atria pressure
- closes AV valves (LUB)
Ejection
- atria relaxed
- ventricles contracted
- pressure in ventricles > aorta pressure
- opening SL valves
Isovolumetric relaxation
- atria relaxed
- ventricles relaxed
- aorta pressure > ventricle pressure > atria pressure
- closing SL valves (DUB)
Rapid filling
- atria emptying (gravity)
- causing Atria pressure > ventricle pressure
- opening AV valves
Ventricles filling
Atrial contraction
Atria emptying (contraction)
- causes atria pressure > ventricle pressure
- opening AV valves
Ventricle filling
End diastolic volume (EDV)
Volume after filling
120 ml/ventricle
Stroke volume (SV)
Volume of blood ejected
Sv = 80ml
Ejection fraction (EF)
Fraction of EDV ejected (SV/EDV)
80/120 = 2/3
Time is systole is less then time in diastole
TRUE or FALSE
True
What are the two cardiac muscle cells and their function?
Contractile cells = pump blood through/out of heart
Pacemaker cells = initiate electrical activity that causes contractile cells to contract
The fibrous skeleton
Electrically separates the atria & ventricles
Pacemaker cell conduction pathway
- Sinoatrial node (SA node)
- Atrioventricular node (AV node)
- Atrioventricular bundle - transfers electrical signal from atria ➡️ ventricle
- R & L bundle branches
- Purkinje fibers
Transmission of cardiac Action potentials through the myocardium are from____________
Gap junctions
Electrical activity of pacemaker cells
Sa node (60-100/min)
- AV node (40-60/min)
- Purkinje fibers (15-40/min)
What is a pacemaker potential and what causes it?
Pacemaker potential = slow change in membrane potential towards threshold
Cause: HCN (NA2+ channels) allowing NA+ into pacemaker cells
Pacemaker cells have a resting membrane potential
TRUE or FALSE
False; no real resting membrane potential
RMP drifts which is called a pacemaker potential
What allows the heart to generate its own action potentials without neural innervation?
Pacemaker cells!!!
In pacemaker cells what causes depolarization and repolarization?
Depolarization = voltage gated ca+ channel
Repolarization = voltage gated K+ channels
Electrical activity (action potential) of myocardial cells mechanism
RMP = -85mv
- opening voltage gated Na+ channels ➡️ Na+ enters ➡️ depolarization
- Slow Ca+2 channels enters / counters small # of open K+ channels ➡️ cause delay Repolarization
- Open voltage gated k+ channels ➡️ k+ leaves ➡️ Repolarization
What causes the myocardial cell to reach threshold potential?
Stimulus from pacemaker cell or nearby myocardial cell
What maintains depolarization in myocardial cells?
Ca2+ influx
Why are Long refractory periods important in myocardial cells?
- prevents summation and tetanus in the heart
➡️allowing heart to completely contract and empty before next AP
What are the two places of calcium being released into the myocardial cells?
- Slow calcium channels
- ca+ enters sarcoplasm during plateau phase of AP - Ca+ release channels in sarcoplasmic recticulum
Long refractory period prevents summation and tentanus in cardiac muscle
TRUE or FALSE
True; it prevents ventricular tachycardia
EKG
Electrical activity of entire heart
P wave
Atrial depolarization
QRS wave
Ventricular depolarization + atrial Repolarization
T waves
Ventricular Repolarization
What is the difference between a AP and an EKG?
Ap - one myocardial cell
EKG - all action potentials from ENTIRE HEART
Do the opening or closing of valves cause noise?
Closing valves make noise
Relationship between EKG, pressure and valves closing
Contraction cause EKG to sense electrical activity
- contraction ➡️ increase pressure ➡️ blood flow ➡️ valves open/close
What are the 5 vessel types
- Artery
- Arteriole
- Capillary
- Venule
- Vein
Portal circulation
2 capillary bends instead of one
Where can portal circulations be found?
- Intestinal tract - liver
- Hypothalamus - pituitary gland
- B/w 2 regions of kidney nephrons
List the four ways that venous return is aided
- Venus valves,
- skeletal muscle pump
- respiratory pump
- arteries pressing on veins
What are the 3 types of capillaries
Continuous, fenestrated, sinusoid
Continuous capillaries
Not leaky, found in the lungs and brain
Fenestrated capillaries
Somewhat leaky, found in kidney,intestines
Sinusoid capillaries
Very leaky, found in bone marrow, the spleen and liver
Myocardial infraction (blocked coronary arteries)
Death to heart muscle tissue
Arteriosclerosis
Hardening of arteries
Atherosclerosis
- causes arteriosclerosis
Fatty plaque
Thrombus
A clot
What conditions initiate damage to endothelium causing vascular disease?
- diabetes
- high blood pressure
- smoking
- high cholesterol
- systemic inflammation
Angiogram
Injects dye into coronary arteries
What a the two ways of revascularization of blocked coronary arteries?
- Insert stent
2/ coronary artery bypass graft (CABG)
- mammary artery
- saphenous artery
What are the 3 functions of the lymphatic system?
- Transport interstitial fluid leaked from the capillaries back to the blood
- Transport absorbed fats (lipids)from small intestine to blood
- Contain lymphocytes that fight infection
Interstitial fluid (ISF)
Blood filtrate formed in the capillaries
What is the function of the lymphatic vessels?
Pick up intestinal fluid leaked from blood capillaries
- pick up lipids (fats) from intestinal tract b/c they are too big to pass/carry through blood vessels
What are the Lymphatic organs and their functions
Thymus - maturation of lymphocytes
Spleen - immune surveillance of blood
Lymph nodes - immune surveillance of lymph
What aids to lymph flow?
Smooth muscle around vessels contraction g
- skeletal muscle pump