Download ANSWER KEY SPRING 2014 (1 point each, total 10 points) BIOL

ANSWER KEY SPRING 2014 (1 point each, total 10 points)
BIOL 204 Lab Homework
Name ____________________________
Refer to the content in the textbook and write the answers in your own words.
The answers provided below are a basic blueprint. Please assess your student responses on their own merit.
1. Define blood pressure. What is systolic and diastolic pressure? What is pulse pressure?
(ans:
text pg 701,703 Class material 3.14-3.18)
0.25 each
BP is the force exerted by blood on the blood vessel wall
Ps is the maximum pressure in an artery during ventricular contraction
Pd is the pressure in the artery at the end of ventricular diastole(relaxation)
PP is the throbbing sensation felt when palpating an artery during systole; measured as Ps-Pd mmHg
2. Define cardiac output, stroke volume, and heart rate. How do SV and HR affect cardiac output?
(ans:
text pg 681-682 Class material 2.49-2.50)
0.25 each
CO=vol of blood ejected from each ventricle per min; - basic info
CO=SVxHR (SV avg 70ml/beat, HR avg 75bpm);
Avg CO= 5.25L/min
SV=vol of blood ejected from each ventricle per beat; basic info
SV=EDV-ESV (EDV avg 120ml, ESV avg 50ml);
Avg SV= 70ml/beat
HR – number of times that the heart beats in one minute
Inc SV= Inc CO; Dec SV=Dec CO
Inc HR=Inc CO; Dec HR=Dec CO
3. Define resistance. How do resistance and cardiac output impact blood pressure?
(ans: text pg 702
Class material 3.16-3.23)
0.3 each
R=the opposition to blood flow due to friction in the blood vessels
Mean arterial pressure = CO X R. an increase in resistance or cardiac output will increase blood pressure. A decrease in cardiac
output or resistance will decrease blood pressure.
4. What are the three important sources of resistance? How do they increase or decrease resistance? (ans: text pg 702
Class material 3.16-3.23)
0.25 each
Blood viscosity, vessel length & vessel diameter
Increase viscosity=Increase in resistance
decrease in viscosity -= decrease in resistance
Increase in length=Increase resistance
decrease in length = decrease in resistance
Inc diameter= decrease in resistance
decrease in diameter = increase in resistance
5. What is atrial Bainbridge reflex? What will be the effect on heart rate and cardiac output?
(ans: text pg 684 Class material 2.54-2.55) 0.3 each
Increased venous return (increased volume of blood in atria) initiates an autonomic reflex. The stretch receptors get activated,
SA node gets activated leading to increased heart rate; increase in CO
ANSWER KEY SPRING 2014 (1 point each, total 10 points)
6. What is venous return? What is end systolic volume and end diastolic volume? What effect will these factors have on
stroke volume and cardiac output? (In other words, what is the effect on SV and CO when these factors increase or decrease?)
(ans:
text pg 681-682
Class material 2.50-2.51)
0.2 each
Venous Return= vol of blood returned to Rt & Lt ventricle per cardiac cycle
ESV=vol of blood remain in ventricle after contraction (systole) per cardiac cycle; avg 50ml
EDV=vol of blood in ventricle when full (diastole) avg 120ml
Inc EDV=Inc SV & Inc CO; Dec EDV=Dec SV & Dec CO
Inc ESV=Dec SV & dec CO;
7. What is mean arterial pressure? How do you calculate mean arterial pressure?
(ans:
text pg 703
Class material 3.16-3.17)
0.5 each
MAP=the average pressure forcing blood to the tissues
MAP=Pd+PP/3 (PP=Ps-Pd)
Please note that the students might also give the formula COX R = MAP. Since this is a lab related homework, one would
assume that they will have to calculate MAP based on the values obtained in lab activity(tangible values). However, some
might choose to give the alternate formula
8. What is the sympathetic and parasympathetic nervous system effect on heart rate?
(ans:
text pg 703
Class material 3.16-3.17) Ans required highlighted
0.5 each
SNS Increases HR PNS decreases HR
9. What are cardioacceleratory, cardioinhibitory, and vasomotor centers? How do they affect blood pressure?
(ans:
text pg 704
Class material 2.54; 3.23-3.26)
0.2 each
Cardioacceleratory center: clusters of neurons located in medulla (part of CV center). Activating CAC will increase SNS effect
on heart - increases HR, increase contractility and increases BP
Cardioinhibitory center: clusters of neurons located in medulla (part of CV center). Activating CIC sends inhibitory impulses to
the heart; decreases HR, decreases contractility and decreases BP
Vasomotor center: Short term control altering BV diameter;
Inc BV diameter=Dec BP
Dec BV diameter=Inc BP
10. What are baroreceptors and chemoreceptors?
(ans:
text pg 705-707
Class material 2.54,3.16-3.17, 3.23-3.27)
0.5 each
Baroreceptors: stretch receptors that respond to changes in BP; located in Carotid sinus, Aortic Arch, & large cervical &
thoracic arteries;
Chemoreceptors: receptors that respond to changes in CO2, pH, and O2 levels; located in Aortic Arch & large cervical arteries
(carotid and aortic bodies); Note: chemoreceptors more imp in regulating RPM than BP