Circulatory System
what are the 3 primary functions of the circulatory system?
transport
protection
regulation (homeostasis)
regarding the movement of gas exchange, what direction of diffusion do partial pressure gradients follow?
high partial pressure to low partial pressure!
How is Urea made in the human body and what is its eventual destination?
Urea is created by the conversion of nitrogenous waste into urea which can be excreted via the kidneys.
what are the 3 types of hormones. briefly explain each one.
1) amines - derived from tryptophan or tyrosine; large and hydrophilic
2) polypeptides - most abundant; large and hydrophilic
3) steroids - derived from cholesterol; lipophilic and hyprophobic
explain the importance and implications of capillary exchange in regards to blood pressure and osmotic pressure
blood pressure drives fluid out of the capillaries. the difference in solute concentration between blood and interstitial fluid (osmotic pressure) opposes fluid movement from the capillaries. that is why there is net filtration at the arteriole end (most fluid lost from capillaries) and net absorption at the venule end.
recall the 3 phases of breathing: inhalation and exhalation. what muscles are contracted and relaxed during both of these processes?
inhalation: intercostal muscles contract, diaphragm contraction
exhalation: intercostal muscles relax, diaphragm relaxes
before the Bowmans capsule describe the events that occur starting with the afferent arteriole. What is the name of the cells found within the glomerulus?
blood enters the afferent arteriole and the capillaries within the glomerulus are highly permeable under high pressure. proteins will remain in the blood due to PODOCYTES and exit via the efferent arteriole.
what are the stages of cell signaling? briefly explain each one.
1) receptor activation - signaling receptor bind to surface receptor, conformational change (activated receptor)
2) signal transduction - activated receptor stimulates signal transduction pathway
3) cellular response - involves intracellular kinase/ generates second messengers
starting from the heart and coming back to the heart, explain the systemic organization of a closed circulatory system.
heart > arteries > arterioles > capillaries > venues > veins > heart
what is the significance of surfactant in newborns?
newborns are born lacking surfactant so they are at higher risk/ more vulnerable to respiratory distress syndrome (RDS). (Recall: surfactant LOWERS surface tension, without it, the alveoli will compress = no air)
explain the events that happen within the proximal tubule. what happens if there is higher concentrations of glucose?
majority of reabsorbing occurs and glucose is dealt. finite number of glucose transporters so the concentration of glucose is independent to the rate of glucose reabsorption - that's why undiagnosed diabetics have glucose in their urine!)
describe the let-down reflex and what hormone is involved. where does it come from. is the positive or negative feedback.
suckling = nerve impulse to hypothalamus = hypothalamus stimulates release of OXYTOCIN from post. pituitary = further release of milk
positive feedback
diagram and explain the 4 phases of cardiac action potential
did you do it? :)
how is carbon dioxide traveled in the blood? Why is CO2 a dangerous waste product?
1) dissolved in plasma
2) bound to proteins (hemoglobin)
3) bicarbonate (MOSTLY)
CO2 combines with H2O to create carbonic acid which is eventually converted into H+ and HCO3-. the more H+ = more acidic = protein dysfunction
describe the events of the loop of Henle and its components. what is permeable/ impermeable? How are we able to make more concentrated urine though countercurrent exchange?
desending loop - permeable to WATER not ions
ascending loop -
thin segment: impermeable to WATER and ions PASSIVELY transported out
thick segment: impermeable to WATER; ions ACTIVELY transported out
the longer the loop, the more concentrated urine we can create! the energy used to create an osmotic gradient is what drives passive absorption of water!
describe the events/ diagram of thyroid hormone cascade.
hypothalamus > TRH > thyrotroph of ant. pituitary > TSH > thyroid gland > TH
TH has negative feedback on hypothalamus and ant. pituitary.
diagram the heart to the best of your ability (structures) and explain the steps of the cardiac cycle and the corresponding blood flow within both pulmonary and systemic circulation
Did you do it? I believe in ya :O
Recall the implications of the "Bohr shift" and diagram the relationship; in other words the relationship between the parent saturation of hemoglobin with O2 and the PO2. How are resting and active states different?
did you do it? :)
describe the 2 main hormones the regulate the collecting duct and their mechanism of action. where are their receptors? Why is urea regulation in the collecting duct important?
Aldosterone: most receptors found in the distal tubule and regulates Na+/ K+ exchange!
ADH: most receptors found in the collecting duct and regulates the amount of water reabsorbed via AQUAPORINS!
in the collecting duct the cells are permeable to urea and is important because Na+ Cl- needs to move DOWN their concentration in the thin segment of the ascending limb of the loop of hence. Urea replaces 1/2 the concentration of Na+ Cl-
think of the big picture. how can Ep lead to different responses with blood flow?
DIFFERENT RECEPTOR TYPES!!! and production of tissue specific molecules (2nd messengers)
think of when you're running from a bear:
Ep will increase blood flow to muscles!
Ep will decrease blood flow to digestive system (not rest and digest time!)
Ep will increase glucose release into blood (need energy to run from bear)