Chapter 11.1 Circulatory system Flashcards
2 chambered heart consists of:
1 atrium & 1 ventricle
Pump only deoxygenated blood
Single circulation
3 chambered heart consists of:
1 Right atrium & 1 Left atrium & 1 Ventricle
Mix oxygenated & deoxygenated blood
4 chambered heart consists of:
1 Right atrium & 1 Left atrium & 1 Right ventricle & 1 Left ventricle
Human heart pathway:
Superior or inferior vena cava, Right atrium, Tricuspid (atrioventricular) valve, Right ventricle, Pulmonary semilunar valve, pulmonary arteries, LUNGS, pulmonary veins, left atrium, bicuspid/ mitral valve, left ventricle, aortic semilunar valve, aorta, body tissues.
Biggest vein:
Vena cava
Superior vena cava function
returns deoxygenated blood from ABOVE the heart
Inferior vena cava function
returns deoxygenated blood from BELOW the heart
Atrioventricular valves
Tricuspid, bicuspid = prevent back flow from ventricles to atria
Pulmonary semilunar valve function
one way blood flow
Pulmonary arteries
Gas exchange deoxygenated blood.
Carries blood AWAY from the heart
Pulmonary veins
Oxygenated blood toward heart
Most muscular vein
Left ventricle ~ ejects oxygenated blood through aortic semilunar valve into aorta.
Largest artery in the body & highest blood pressure
Aorta
Pulmonary circulation:
Deoxygenated blood
Vena cava, right atrium, tricuspid valve, right ventricle, pulmonary semilunar valve, pulmonary arteries, lung
System circulation:
Oxygenated blood
Lung, pulmonary veins, left atrium, bicuspid/mitral valve, left ventricle, aortic semilunar valve, aorta, body tissues.
Heart pumps blood itself via what type of circulation:
Coronary circulation
Coronary circulation
beings when coronary artier ~ branch off aorta & provide oxygen to myocardium
Myocardium (muscular layer of heart)
contains cardiomyocytes
Endocardium ~ beneath the myocardium
Pericardium:
sack of fluid surrounding heart
Fluid in sack called
Serous pericardium
Serous pericardium contains
protein ~ acts as lubricant
reduces friction
Human cardiac cycle:
Sinoartrial node, atrioventricular (AV) node, bundle of HIS, purkinje fibers
Sinoatrial node “pacemakers of heart”
Greatest automaticity in the heart
Reach threshold & stimulates AP
Parasympathetic vagus nerve
Depolarizes through both atria & send their blood into ventricles
Parasympathetic vagus nerve
Default signal ~ to slow down SA node to normal rate of 60-90
Atrioventricular node
Adds a brief delay in b/w atria contracting and ventricles contracting
Electrical signal sent to bundle of HIS ~ by AV node
Bundle of his
Located in interventicular system
Carries signal to the base of the heart through right & left bundle of his to purkinje fibers
Purkinje fibers
Located in walls of ventricles
Coordinates contraction b/w ventricles
Systole
Right after ventricles EJECT their blood into arteries
Blood pressure highest
Diastole
Right after atria CONTRACT to fill the ventricles
Myocardium relaxed at this point
Blood pressure lowest
Lub –> systole
Left & Right atria = relaxed
Left & Right ventricle = contract
Semilunar valve = open
Atrioventricular = close/snap shut
Dub –> diastole
Left & Right atria = contract
Left & Right ventricle = relaxed
Semilunar valve = close
Atrioventricular = open
Signal transduction through what? (4)
Intercalated discs, Desmosomes, gap junction, syncytium
Intercalated discs:
contact point between cardiomyocytes (contain desmosomes, gap junction)
Desmosomes
Proteins hold and adhere cardiomyocytes together
Gap junctions
Protein tunnels ~ connect cytoplasm of near cardiomyocytes
Allow ions, molecules to directly pass
Propagate action potential
Syncytium
connection of many heart cells together
Syncytium
connection of many heart cells together
Stroke volume
Volume of blood pumped from HEART WITH EACH BEAT
Cardiac output
Volume of blood pumped by HEART IN ONE MINUTE
CO = HR * SV
Total Peripheral resistance
Total amount of resistance that blood faces when flowing
Vasoconstriction:
blood vessels increase TPR
Vasodilation:
Blood vessels decrease TPR
Mean arterial pressure:
Average arterial pressure during ONE CARDIAC CYCLE
MAP = CO * TPR
What are 3 three layers of blood vessels?
Tunica intima, Tunica media, Tunica Externa
Tunica intima
contains endothelial cells ~ reduce friction
Surround lumen of blood vessels
Tunica media
contains smooth muscles ~ control diameter
Above intima
Tunica Externa
contains collagen protein ~ protect vessel nerve and elastin
Above media
Characteristics of arteries:
Carry blood AWAY from the heart ~ oxygenated
Elastic vessels - thick tunica media
Hold less blood
Highest blood pressure
Characteristics of arterioles:
Carries oxygenated blood Smaller diameter Resistance vessels Blood pressure drops the most Vasoconstriction ~ maintain blood temp Vasodilation ~ cools us down
Characteristics of capillary:
Branch off to arterioles and connect to venules
One endothelial - thick tunica intima
Smallest in diameter
Characteristics of veins/venules:
Carry blood TOWARD the heart ~ deoxygenated
Veins are wider
Hold more blood
Lowest blood pressure
Contains valves (skeletal muscle & respiratory pump)
Both: have smooth muscles
Effects of abdomen pressure on veins?
increase pressure - squeeze veins - moves blood forward
Effects of thoracic cavity pressure on vena cava & right atria?
Decrease ~ negative pressure in vena cava & right atria = expand = pull blood inside
What are 2 portal systems?
Hepatic portal vein
Hypophyseal portal vein
Hepatic portal vein
Moves blood directly from digestive tract to liver
Hypophyseal portal vein
Hormones from hypothalamus enter anterior pituitary
Prevents hormones from being diluted
Blood clothing cascade “Positive feedback mechanism”
Damaged tissue - exposes collagen
Exposed collagen - causes platelet activation - platelet aggregates - forming platelet plug.
Thromboplastin (released by platelet) - converts prothrombin into thrombin.
Thrombin converts fibrinogen into fibrin - blood clots forming hemostatic plug.
Which vitamin is important for clothing factors (prothrombin)?
Vitamin K
Blood consists of:
Plasma, leukocytes, erythrocytes, Platelets
Plasma
contains water, proteins, hormones
Leukocytes
immune cells, contains nucleus
Erythrocytes
Anucleate ~ maximizes capacity to carry oxygen
Have antigens (sugars & proteins)
Hemoglobin molecules
Platelets (Thrombocytes)
anucleate cell fragments
What is a precursor to platelets ?
Large bone marrow megakarocytes
Type of blood universal recipient ?
Type AB
Type of blood universal donor?
Type O
Placenta
provides oxygen & nutrient supply to fetus
Umbilical cord
oxygen & nutrients travels to fetus
Umbilical vein
Carries oxygenated blood entering fetus
Ductus venosos
allows oxygenated blood entering fetus to flow into inferior vena cava & mix with deoxygenated blood.
Foramen ovule
oxygenated blood travels from right atrium to left atrium