ch. 40 Flashcards
what are the three functions of the circulatory system?
- transportation
- regulation
- protection
what does the CS transport?
nutrients, glucose, and metabolic waste
what does the CS regulate?
hormones and temperature
how does the CS act as protection?
injury and clotting; pathogens and WBCs
what is the circulatory fluid in sponges and hydra?
water
what are characteristics of a fish CS?
- 2 chambers
- efficient gills
- systemic loop only
- low blood pressure
- electrical impulse
what kind of CS do fishes have?
closed
what are characteristics of an earthworm’s CS?
- completely separate circulatory fluid
- blood enclosed in vessels
- (oxygenated) heart —> arteries —> tissues
- (deoxygenated) tissues —> veins —> heart
what are the characteristics of an amphibian’s CS?
- 3 chambers
- double circulation (systemic, pulmonary, and cutaneous)
- blood mixture (nearly complete)
- electrical impulse
- metabolism?
- temp regulation?
what are the characteristics of a non-crocodilian reptiles CS?
- 3 chambers
- partial septum
- double circulation (systemic, pulmonary)
- blood mixing (nearly separate)
- metabolism?
- temp reg?
what are the characteristics of crocs, birds, and mammals CS?
- 4 chambers
- complete blood separation
- no blood mixing
- double loop (systemic, pulmonary)
- sinoatrial node
- metabolism?
- temp reg?
what does the atria do in the mammalian heart?
collects blood that is returning to the heart; is stretchy
what do the atrioventricular valves do in the mammalian heart?
connects the atria to the ventricle
what are the two atrioventricular valves? what do they connect?
- tricuspid (right atria to right ventricle)
- mitral (left atria to left ventricle)
what is the function of the ventricles?
contractions, moving blood away from the heart
what do the semilunar valves connect?
ventricles to vessels
what are the two types of semilunar valves and what do they connect?
- pulmonary (right ventricle to pulmonary artery)
- aortic (left ventricle to aorta)
when the heart contracts, what do the right and left atria receive blood from?
right- body
left- lungs
what happens when a sinoatrial node (SA nodes) fires?
what happens with an atrioventricular node fires?
impulses down myoseptum and causes ventricles to contract
what is a p-wave in an electrocardiogram?
- activation of the atria
- an atrial contraction / atrial depolarization
what is a t-wave in an EKG?
- recovery wave
- ventricular relaxation / repolarization
- distole (80 mmHg)
what is the QRS complex in an EKG?
- activation of the ventricles
- ventricular contraction / depolarization
- systole (120 mmHg)
increase in heart rate?
cardioaccelerator, norepinephrine, sympathetic
decrease in heart rate?
cardioinhibitor, acetylcholine, parasympathetic
what are baroreceptors?
aortic arch and carotid arteries
what do baroreceptors do?
sense contractions or expansions of blood vessels and low or high blood pressure
what happens if a baroreceptor senses high BP?
cardiac center of medulla increases frequency of impulses —> decreases sympathetic, increases parasympathetic—> decrease heart rate, stoke volume, vasodilation
what are the components of blood?
55% plasma, buffy coat, 45% hematocrit
what is plasma made up of?
95% water
what does blood plasma transport?
• Nutrients
• CO2 (25%)
• Nitrogenous waste
• Cholesterol
• Ions
• Hormones
• Proteins (Albumin)
what does erythropoietin do?
stimulates RBC production (in bone marrow)
what are RBCs?
– “erythrocytes”
– Hemoglobin w/Fe2+
what do RBCs transport?
O2 and CO2 (75%)
what is anemia caused by?
• Low Fe2+ , Genetic
• Vitamin B, Hemolytic
what are WBCs?
“leukocytes”, part of the Immune system, Defense component
what are platelets?
cellular fragments, megakaryocytes
what do platelets do?
initiate clotting
what do platelets adhere to?
exposed collagen
what two inactive proteins are activated by clotting factors?
- prothrombin to thrombin
- fibrinogen to fibrin
what are characteristics of arteries?
- more elastic laters
- thicker smooth muscles
- thinner connective tissue
- arteries to arterioles
what are characteristics of veins?
- few elastic layers
- thin smooth muscle
- thicker connective tissue
- veins to venules
what are characteristics of capillaries?
- 1 cell thick
- 1 mm length
- used for exchange and absorption
- greatest cross-sectional area
what is vasoconstriction?
narrowing of a blood vessel
what is vasodilation?
widening of a blood vessel
what is the purpose of vasoconstriction and vasodilation?
to regulate body heat
what does vasodilation do?
increase in heat loss across epidermis
what does vasoconstriction do?
increase in heat loss across epidermis
what are varicose veins?
veins that become enlarged because the valves no longer close properly, allowing blood to flow backward
where are varicose veins most commonly found?
the legs
how are veins different from arteries (structure)?
less muscle and more flexible
what is atherosclerosis?
cardiovascular disease
causes:
- high BP
- high cholesterol
- plaque formation
- vessel blockage
treatment:
- bypass surgery
what causes strokes and what do strokes cause?
blood to the brain is blocked; partial paralysis of body
what are myocardial infarctions?
- coronary arteries are blocked
- myocardial cells die
- 20% of all deaths in US
what is an aneurysm?
high blood pressure where ballooned arteries rupture
grass hopper CS
- open CS
- no distinction btwn body fluids and circ fluids
- uses a hemolyph (cavity were combined fluids are)
- heart —> fluid —> channels and cavities —> drains back to heart
what is the heart rate controlled by?
the SA node and autonomic nervous system
what happens with the ventricles during contraction of the heart?
- they contract (systol)
- atrioventricular valves forcibly close
- pressure up, semilunar valves open
- blood —> vessels
- relaxation
- semilunar valves close
what happens with the atria during contraction of the heart?
- pressure up, atrioventricular valves open
- blood —> ventricles (80%)
- atria contracts (20%)
- fills relaxed ventricles (diastole)
what does systole mean?
contraction phase of cardiac cycle when the ventricles are pumping blood into the arteries
what is diastole?
relaxation phase of the cardiac cycle when the heart is relaxed and the ventricles are filling with blood
what is it called when there is no stimulus to the heart?
heart at rest / diastole
what is another name for a ventricular contraction?
systole
what happens when sinoatrial nodes fire?
- APs spread through atria
- atria contract
- APs spread to AV-node
what does venous mean?
PCO2: partial pressure of carbon dioxide in the veins (40 mm Hg in the pulmonary veins)
PO2: partial pressure of oxygen in the veins (100 mm Hg in the pulmonary veins)
