LQB185 Chapter Notes - Chapter 21: Vascular Resistance, Mean Arterial Pressure, Blood Vessel

60 views6 pages

byzantiumcheetah91

25 May 2018

School

Department

Course

Professor

For unlimited access to Textbook Notes, a Class+ subscription is required.

21.3 Hemodynamics: Factors Affecting Blood Flow

➢ Blood flow is the volume of blood that flows through any tissue

➢ Cardia Output (CO) depends on 2 factors:

1. Pressure differences

2. resistance

➢ Blood Pressure

- Contraction of ventricles generates blood pressure

- Mean arterial pressure (MAP) is the average blood pressure in

arteries.

➢ Vascular Resistance

- Opposition to blood flow die to friction between blood and walls

of vessel

- Resistance depends on:

1. Size of the lumen: smaller the lumen=greater the resistance

2. Blood viscosity: higher the blood viscosity= higher the

resistance, thickness of the blood, ration of red blood cells:

plasma volume.

3. Total blood vessel length: longer the vessel= greater resistance,

resistance is directly proportional to length of blood vessel

- Systemic Vascular Resistance (SVR): refers to all vascular

resistances offered by systemic blood vessels.

find more resources at oneclass.com

Unlock document

This preview shows pages 1-2 of the document.
Unlock all 6 pages and 3 million more documents.

Already have an account? Log in

➢ Venous Return

- Volume of blood flowing back to heart.

- Besides the heart, 2 other mechanism help pump blood from the

lower body back to the heart.

1. Skeletal muscle pump: milking that causes contraction that

drive venous blood toward heart

2. The respiratory pump: compression and decompression of

veins

➢ Velocity of Blood Flow

- The speed of blood flow, blood moves slower

and slower s blood moves further away from

the heart. Slowest in capillaries.

- Circulation time: time required for blood to

pass R) atrium to L) atrium and all the way

back to the R) atrium again.

21.4 Control of Blood Pressure and Blood Flow

➢ Several interconnected negative feedback systems control BP b adjusting

heart rate, stroke volume, systemic vascular resistance and blood

volume.

➢ Role of Cardiovascular Centre (CV)

find more resources at oneclass.com

Unlock document

This preview shows pages 1-2 of the document.
Unlock all 6 pages and 3 million more documents.

Already have an account? Log in

Document Summary

Blood flow is the volume of blood that flows through any tissue. Cardia output (co) depends on 2 factors: pressure differences, resistance. Mean arterial pressure (map) is the average blood pressure in arteries. Opposition to blood flow die to friction between blood and walls of vessel. Systemic vascular resistance (svr): refers to all vascular resistances offered by systemic blood vessels. Volume of blood flowing back to heart. The speed of blood flow, blood moves slower and slower s blood moves further away from the heart. Circulation time: time required for blood to pass r) atrium to l) atrium and all the way back to the r) atrium again. 21. 4 control of blood pressure and blood flow. Several interconnected negative feedback systems control bp b adjusting heart rate, stroke volume, systemic vascular resistance and blood volume. Role of cardiovascular centre (cv) (cv) in the medulla oblongata helps regulate heart rate and stroke volume.

Related Questions

1. Reflexes associated with Golgitendon organs prevent skeletal muscles from

a. stretching toofar

b. contracting with too muchforce

c. accumulating too much lacticacid

d. exercising toolong

2. Why do plasma glucoseconcentrations start to decline after prolonged enduranceexercise?

a. Glucagon releasedecreases.

b. Insulin releaseincreases.

c. Cortisol releasedecreases.

d. Glycogen stores aredepleted.

3. During a graded aerobic exercise,

a. SBP gradually increases while DBP remains same or slightlydecreases.

b. SBP remains same or slightly decreases while DBP graduallyincreases.

4. Factor(s) affecting blood pressure is(are)

a. HR.

b. SV.

c. Q.

d. TPR.

e. All of above.

5. Where does waterportion of sweat come from?

a. Inside of muscle cells.

b. Urine.

c. Plasma.

6. End-diastolic volume (EDV) -end-systolic volume (ESV) =

a. cardiac output(CO).

b. mean arterial pressure(MAP).

c. stroke volume(SV).

d. ejection fraction(EF).

7. The major factor affecting blood flow is

a. viscosity ofblood.

b. length of vessel.

c. radius of vessel.

d. shear stress ofvessel.

8. Accumulation of metabolicby-products in muscle (H⁺,CO₂, heat) leads to

a. vasoconstriction.

b. vasodilation.

c. sympatheticactivation.

d. reduced muscle bloodflow.

9. During a grated exercise until the point ofventilator threshold (VT) occurring,

a. pulmonary ventilation (VE) increases proportionally to exerciseintensity increase.

b. pulmonary ventilation (VE) increases disproportionally toexercise intensity increase.

10. Immediately stopping a steady-statesubmaximal exercise, VE steeply decreases. This decrease is dueto

a. decrease in PCO₂, H⁺, and the coretemperature (metabolic effect).

b. decrease in neural input from CNS and feedback from activemuscle.

11. During the recovery period after asteady-state submaximal exercise, VE gradually decrease because

a. decrease in PCO₂, H⁺, and the coretemperature (metabolic effect).

b. decrease in neural input from CNS and feedback from activemuscle.

12. Valsalvamaneuver is dangerous because

a. sore abdominal muscles.

b. a drop in blood pressure if Valsalva maneuver iscontinued.

c. a dangerous rise in blood pressure immediately afterstarting Valsalva maneuver.

d. b and c are correct.

e. All of above are correct.

13. The point atwhich pulmonary ventilation (VE) increases disproportionately withoxygen consumption (VO₂) during graded exercise iscalled

a. ventilatory threshold (VT).

b. lactate threshold (LT).

c. anaerobic threshold (AT).

14. Which condition duringexercise induces the right shift of hemoglobin's oxygen-binding affinity curve(Bohr effect)?

a. ADP accumulation

b. lower pH

c. mechanical compression ofmuscle capillaries

d. local hypoxia(low O₂)

15. How is bloodpressure response during submaximal exercise different between armsand legs?

a. Arms have a higher.

b. Legs have a higher.

c. They are the same

d. They can't be compared

16. Which of thefollowing does not increase the heart'sstroke volume?

a. Enhanced cardiac filling and ejection

b. Neurohormonal influence

c. Training adaptations that expand blood volume

d. Training adaptations that increase resistance to bloodflow

17. Which of the following willdecrease stroke volume (SV)?

a. increased preload

b. increasedcontractility

c. increased Calcium(Ca²⁺) concentrations

d. increasedafterload

18. For two athletes with sameVO₂max, An athlete who has _____ lactate thresholdpredicts better performance.

a. higher

b. lower

c. It doesn

ochrecricket710

LQB185 Chapter Notes - Chapter 21: Vascular Resistance, Mean Arterial Pressure, Blood Vessel

Document Summary

Get access

Related Documents

IMED3001 Study Guide - Quiz Guide: Blood Vessel, Carotid Sinus, Internal Carotid Artery

HTHSCI 1H06 Lecture Notes - Lecture 5: Perfusion, Adrenal Gland, Medulla Oblongata

HTHSCI 1H06 Lecture Notes - Lecture 5: Mean Arterial Pressure, Internal Carotid Artery, Common Carotid Artery

Related Questions