Test 5- Circulatory System Flashcards
Whatre the three main types of blood vessels, order them from thick to thin, which carry blood away and to the heart?
Arteries: thick layer of smooth muscle to carry blood away from the heart
Veins: Thin layer of smooth muscle with valves to carry blood back to the heart and prevent back flow
Capillaries: Very thin walled vessels to exchange nutrients and wastes with blood vessels
What do capillaries join together
Arterioles (small arteries) to venules (small veins)
Whatre precapillary sphincters and arteriovenuses shunts
Precapillary sphincters within capillaries control blood flow to specific areas
Arteriovenus shunts (also known as as astamoses), are direct connections between the arterioles, can bypass capillary beds to bring blood to an area more needed (running directs some blood away from the digestive system)
What is blood made of
Plasma and formed elements (rbc, wbc, platelets)
What are four plasma proteins, what do they do
Albumin: transports bilirubin from the spleen to the liver
Lipoproteins transport cholesterol
Prothrombin and fibrinogen aids in blood clotting
Where are antibodies produced, whats the scientific name for them, what do they do
Antibodies produced by B lymphocytes (cells), helps fight infection
Immunoglobulins
Whats the scientific name for rbc, what do they contain and not contain
Does not contain a nucleus
Contains hemoglobin to transport oxygen and co2
Where are platelets, rbc, and wbc produced
Red bone marrow
Do rbcs live for a long time? Where do they get dismantled? Whats produced when theyre dismantled and whats reused
They live for around 120 days (not a long time)
They get dismantled in the liver and spleen when worn out
Iron reused to make more rbcs
Heme portion of hemoglobin produces biliverdin, beocming bilirubin
How is bilirubin excreted
Excreted as bile pigments in bile
Whats the stimulus, target, source, and effect of EPO? Whats the full name of EPO?
Erythropoietin
Source: kidneys
Stimulus: kidneys detect low levels of oxygen in the blood
Target: Femur’s red bone marrow
Effect: increases red blood cell production (negative feedback)
What regulates the acid base balance of the blood? How?
Kidneys (and the respiratory system) regulate
ExcretesH+ ions and reabsorbs HCO3- (bicarbonate) ions
When too acidic: hydrogen ions combine with bicarbonate ions to make carbonic acid (H2CO3)
Whats the ph of urine
6 or lower
Whatre the two types of wbcs, whats the scientific name of wbcs, whats the difference between the two types, give examples of the types
Leukocytes
Granular: contains enzymes and proteins that defend against the body by engulfing and digesting antigens with their many vesicles (ex. Neutrophils, eosinophils, basophils)
Agranular: spherical, kidney shaped nucleus, produces antibodies (ex. Monocytes and lymphocytes)
Whats the scientific name for platelets, where do they come from, are they a cell?
Thrombocytes
Comes from large cells produced by the red bone marrow called megakaryocytes, which fragment into platelets
Not cells
What is the role of platelets
Aids in blood clotting
How do platelets help with blood clotting
Releases a clotting factor called prothrombin activator, which helps activate prothrombin
What does prothrombin combine with, what does it become?
Prothrombin combines with calcium ion to become thrombin (active enzyme)
What does thrombin do
Helps fibrinogen combine with calcium ion to form fibrin
Of fibrin and thrombin, which is an enzyme?
Thrombin
What does fibrin do
Forms a mesh made of fibers that traps rbcs, creating a clot to stop/plug the bleeding
What breaks down fibrin
Once tissues start to heal, the enzyme plasmin breaks down the fibrin
Is blood hypotonic or hypertonic to tissue fluid typically
Hypertonic
Why do arteries have higher blood pressure than veins
Because heart directly pumps blood out, while blood returns to the heart via skeletal muscle contractions
Describe what occurs at the arteriole end of capillaries and why this occurs
Because blood pressure is more than osmotic pressure, water, oxygen, and nutrients leave the capillary, by diffusing into the cells
Describe what occurs at the venous/venule end of the capillaries and why this occurs
Because osmotic pressure is more than blood pressure, water and wastes from the tissue body cells re enter the capillary by diffusion
Where does excess tissue fluid end up, why is there excess tissue fluid?
Excess tissue/interstitial fluid enters lymphatic capillaries, and the fluid is returned to the blood at the subclavian veins
If osmotic pressure is too low or blood pressure is too high, more fluid may leave the capillaries than entered
Whats lymph
interstial fluid that has entered the lymphatic capillaries
what happens if a blood type is transfused into a recepient with b blood type
A antigens on blood get attacked by a antibodies from the recepient, causing clumping and blocking blood vessels
Whats the term for blood cells clumping
Agglutination
Whats the universal recepient and donor
O- is universal donor, AB+ is universal recepient
What is heart muscle called
The cardiac muscle/myocardium
Whats the pericardium
A thick membrane that the heart lies in, which secretes a lubricating liquid
Describe the pathway of deoxygenated blood within the heart
Superior/inferior vena cava, right atrium, tricuspid atrioventricular valve, right ventricle, pulmonary semilunar valve, pulmonary trunk, left right pulmonary arteries, lungs
Describe the pathway of oxygenated blood within the heart
Lungs, pulmonary veins, left atrium, bicuspid/mitral valve, left ventricle, aortic semilunar valve, aorta, body
What are the three steps in the cardiac cycle
- Atria contract together
- Two ventricles contract eachother
- Whole heart relaxes
What is systole and diastole
Systole:: contraction of heart chambers
Diastole: relaxation
What sound does the heart make and where does it come from
Lub dub
Due to the closing of the heart valves
Which step produces the lub and which step produces the dub sound
Lub: step two (ventricles contract)
Dub: heart relaxes
What is the pacemaker of the heart and what does it do, where is it found
The sinoatrial node in the right atrium initiates the heartbeat by generating electrical signals
What does the av (atrioventricular) node do? Where is it found
Receives the stimulus and conveys it to the purkinje fibers to contract the atria, then indirectly causing the ventricles to contract
Found in the right atrium
Where is the cardiac control center found, what does it do
In the medulla oblongata of the brain
Regulates the heartbeat (extrinsic) by speeding or slowing it down with the autonomic nervous system
What are the two branches of the autonomic nervous system and what are their differences
Parasympathetic: slows heart rate, promoting relaxation
Sympathetic: increases heart rate, controlling fight/flight responses
Where do the hormones epinephrine and norepinephrine get released from, what do they do, whats another name for them
Epinephrine: adrenaline
Norepinephrine: noradrenaline
From the adrenal medulla (found near kidney) , stimulating faster heart rate
What does ecg stand for and what does it do
Electrocardiogram is a recording of the electrical changes that occur in the myocardium (heart tissue) during a cardiac cycle
What ion helps contract the heart, how
Calcium ion enters the cardiac muscle cells via channels, contracting the heart
What occurs during the p, qrs, and t wave
P: atrial contraction
Qrs: ventricle contraction
T: ventricle relaxing
Why is the heart considered a double pump
Because it circulates blood through the pulmonary and systemic circuits at the same time
What are the two circuits in the body
Pulmonary: within the heart
Systemic: within the body
How is blood transported to the intestines from the heart and back
Aorta, mesenteric artery, intestines, hepatic portal vein, liver, hepatic vein, inferior vc
How is blood from the heart transported to the kidneys and back
Aorta, renal artery, kidneys, renal vein, inferior vc
How is blood from the heart transported to the legs and back
Aorta, iliac artery, iliac vein
How is blood transported from the heart to the arms and back
Aorta, subclavian artery, brachial artery, arm, brachial vein, subclavian vein
How are nutrients transported to the heart itself
Coronary artery, heart, cardiac vein
How is blood from the heart transported to the head and back
Carotid artery, head, jugular vein
What is blood pressure measured by, what is the average
Sphygmomanometer
120 mm hg systolic over 80 mm hg diastolic
Where is blood pressure measured
Measured with the brachial artery
Why do varicose veins develop
When high blood pressure in the veins stretches vein walls, cretaing weak valves, then backflow of blood and pooling
Whats osmoregulation, what organ maintains it and how
The maintenance of water salt balance
Kidneys maintain the water salt balance of the body by controlling the excretion and reabsorption of ions (mostly sodium)
What is the source, stimulus, target, and effect of renin
Source: kidneys
Stimulus: low blood pressure (typically due to low blood volume)
Target: adrenal cortex
Effect: adrenal cortex releases aldosterone
What is the source, stimulus, target, and effect of aldosterone
Source: adrenal cortex
Stimulus: renin
Target: kidneys
Effect: promotes reabsorption of sodium in the kidneys
What is the source, stimulus, target, and effect of adh? What does adh stand for? What detects the stimulus?
Stimulus: hypertonic blood (usually due to lower blood volume) detected by neurosecretory cells in the hypothalamus
Source: hypothalamus
Target: first the posterior pituitary gland, then the kidneys
Effect: aids in the reabsorption of water, increasing blood volume by opening up kidney aquaporins
Stands for antidiuretic hormone
What is the source, target, stimulus, and effect of anh? What is the stimulus detected by? What does anh stand for?
Atrial natriuretic hormone
Stimulus: blood volume too high detected by stretch receptors in cardiac cells
Source: cardiac cells in atria
Target: kidneys and adrenal cortex
Effect: inhibits secretion of renin and aldosterone, which excretes more sodium causing more water to be excreted meaning blood volume drops
What are diuretics, give examples
Chemicals that lower blood pressure by increasing urine output
Alcohol inhibits secretion of adh
Caffeine decreases reabsorption of sodium
Is less or more adh produced at night and why
More produced at night, reducing the amount of urine produced
