Chapter 16 - Guyton

Question 1

It is believed that most water-soluble substances diffuse through the capillary membrane along the?

Answer 1

intracellular clefts (water, sodium ions, chloride ions, glucose)

Question 2

Special types of pores in the capillaries of specific organs.

Answer 2

brain (tight junctions), liver (wide open clefts to allow lots of exchange), GI capillary membranes (midway between muscles and liver), fenestrae of the kidneys (small molecular and ionic structures can filter through glomeruli

Question 3

Vasomotion

Answer 3

intermittent contraction of the metarterioles and precapillary sphincters

Question 4

What is the primary factor regulating vasomotion?

Answer 4

oxygen concentration

Question 5

Why can oxygen and carbon dioxide readily diffuse through the capillary cell membrane?

Answer 5

they are lipid-soluble

Question 6

The “net” rate of diffusion of a substance through any membrane is proportional to the __________ _________ of the substance between the two sides of the membrane.

Answer 6

concentration difference

Question 7

About one sixth of the total volume of the body consists of spaces between cells, which collectively are called the __________.

Answer 7

interstitium (interstitial fluid)

Question 8

Starling forces (determine fluid movement through the capillary membrane)

Answer 8

capillary pressure, interstitial fluid pressure, plasma colloid osmotic pressure, interstitial fluid colloid osmotic pressure

Question 9

Is the pressure greatest at the arterial or venous end of the capillary?

Answer 9

reabsorption pressure is considerably less than the filtration pressure at the capillary arterial ends, but remember that the venous capillaries are more numerous and more permeable than the arterial capillaries, so that less reabsorption pressure is required to cause inward movement of fluid

Question 10

Essentially all the lymph vessels from the lower part of the body eventually empty into the _______ duct, which in turn empties into the blood venous system at the juncture of the left internal jugular vein and left subclavian vein.

Answer 10

thoracic

Question 11

Lymph from the right side of the neck and head, the right arm, and parts of the right thorax enters the right ______ duct (much smaller than the thoracic duct), which empties into the blood venous system at the juncture of the right subclavian vein and internal jugular vein.

Answer 11

lymph

Question 12

In addition to the pumping caused by intrinsic intermittent contraction of the lymph vessel walls, any external factor that intermittently compresses the lymph vessel also can cause pumping. In order of their importance, such factors are:

Answer 12

• Contraction of surrounding skeletal muscles
• Movement of the parts of the body
• Pulsations of arteries adjacent to the lymphatics
• Compression of the tissues by objects outside the body

Question 13

The two primary factors that determine lymph flow are:

Answer 13

the interstitial fluid pressure and the activity of the lymphatic pump

Question 14

The lymphatic system also plays a central role in controlling:

Answer 14

1) the concentration of proteins in the interstitial fluids; 2) the volume of interstitial fluid; 3) the interstitial fluid pressure