Peripheral Circulation and Respiration

Question 1

What are the two main functions of the vascular system?

Answer 1

distribution and exchange

Question 2

What makes up the middle layer of the arterial wall and determines the size of the artery?

Answer 2

smooth muscle

Question 3

What makes up the inner layer of the material wall and functions to control flow, protection from clots, and regulation of permeability?

Answer 3

endothelial cells

Question 4

Which layer of the arterial wall contains nerves that contribute to control of contraction?

Answer 4

sympathetic vasoconstrictor fiber

Question 5

The majority of resistance to flow is contributed at the level of the _______.

Answer 5

arterioles

Question 6

What kind of muscle is found in the vascular, bronchi, and gastric sections?

Answer 6

non-striated smooth muscle

Question 7

What are a few differences between VSM cells and striated muscle cells?

Answer 7

VSM cells are smaller, only have one nucleus, and a smaller sarcoplasmic reticulum

Question 8

In stead of “T” tubules what do VSM cells use?

Answer 8

Caveolae

Question 9

In cardiac muscle what provides an electrical link between cells?

Answer 9

gap/intermediate junctions

Question 10

What is the anchor in thin filaments which provides the mechanical connection between cells and contributes to elects recoil?

Answer 10

dense bodies

Question 11

What is the supporting protein which links the dense bodies but does not contribute to the contractile process?

Answer 11

intermediate filaments

Question 12

What is the difference in sarcomere of VSM?

Answer 12

fewer in number and not regularly organized as on cardiac and skeletal

Question 13

What is surrounded by smooth muscle that regulates vascular time and thus resistance to flow?

Answer 13

arterioles

Question 14

What is where exchange of material with surrounding tissues takes place?

Answer 14

capillaries

Question 15

What collects blood flowing out of the capillary bed?

Answer 15

venules

Question 16

What collects interstitial or extravascular fluid and returns it to venous circulation?

Answer 16

lymphatics

Question 17

Why are capillaries good exchange vessels?

Answer 17

very thin capillary wall which contains holes/pores, blood also flows very slowly

Question 18

Why is blood flow at the capillaries so low?

Answer 18

they represent the highest total cross sectional are in circulation

Question 19

What functions to return fluid and plasma protein that have leaked out of the capillaries back to the circulating pool?

Answer 19

lymphatic system

Question 20

What covers the surface of the lungs?

Answer 20

visceral pleura

Question 21

What lines the walls of the thoracic cavity?

Answer 21

parietal pleura

Question 22

What is between the visceral and parietal pleura?

Answer 22

pleural cavity

Question 23

What dictates air flow in lungs?

Answer 23

changes in pressure in the intrapleural space governed by changes in volume of the thoracic cavity

Question 24

What must be created in the lungs in order to drive the net movement of air from the atmosphere into the lungs?

Answer 24

a pressure gradient

Question 25

What does contraction of the diaphragm and external intercostal muscles do?

Answer 25

expands volume of thoracic cavity

Question 26

What is volume moving past a given point per unit time?

Answer 26

velocity

Question 27

What is layers of flow moving laterally in a distinct way typically in the smaller branched portions?

Answer 27

laminar flow

Question 28

What is increased velocity of flow leading to turbulence and increased resistance typically in larger airways, ventricles, aorta, and pulmonary artery?

Answer 28

turbulent flow

Question 29

What type of flow occurs in capillaries and erythrocytes?

Answer 29

single-file

Question 30

What is the equation for pulse pressure?

Answer 30

Systolic pressure - diastolic pressure

Question 31

What is the equation estimated mean arterial pressure?

Answer 31

diastolic pressure + pulse pressure/3

Question 32

What causes systolic arterial pressure?

Answer 32

during systole the flow of blood from the heart to the arteries exceeds the flow out of the arteries through the arterioles leading to extension/stretching

Question 33

What is diastolic arterial pressure?

Answer 33

during diastole the elastic recoil of the arterial walls provides the driving force to propel blood out of the arteries and into vessels

Question 34

What is the pressure due to the presence of colloids, large proteins or other non diffusible materials that remain within the blood plasma, and draws water from the interstitial space back into the capillary?

Answer 34

oncotic pressure

Question 35

True or false: smooth muscle can be stimulated to contract without an action potential.

Answer 35

True

Question 36

In smooth muscle how can muscle tone be decreased?

Answer 36

inhibiting MLCK binding or activating myosin depolarization