4- transfer of materials between the circulatory system and cells

Question 1

formation of tissue fluid

Answer 1

• at the arterial end of capillaries, blood enters under high hydrostatic pressure, pushing water and other small molecules out of the capillary wall to form tissue fluid
• this process is known as ultrafiltration

Question 2

reabsorption of tissue fluid

Answer 2

• at the venous end of capillaries, hydrostatic pressure is lower inside the capillaries, allowing for the reabsorption of water and waste materials back into the capillary
• this process is known as reabsorption

Question 3

role of hydrostatic pressure

Answer 3

• hydrostatic pressure is the force exerted by fluid against a surface
• at the arterial end of capillaries, high hydrostatic pressure forces fluid out, forming tissue fluid
• at the venous end, lower hydrostatic pressure allows fluid to be reabsorbed back

Question 4

role of oncotic pressure

Answer 4

• oncotic pressure is the osmotic pressure exerted by proteins, specifically albumin, in the blood plasma that tends to pull water into the circulatory system
• it counteracts hydrostatic pressure, aiding in the reabsorption of water at the venous end
• it also prevents too much fluid from leaving the capillaries at the arterial end

Question 5

interchange of substances of tissue fluid:

Answer 5

• the formation and reabsorption of tissue fluid allows for the exchange of nutrients, oxygen and waste products between the blood and the body’s cells
• nutrients and oxygen diffuse out of the tissue fluid and into cells while waste products diffuse out of cells and into the tissue fluid, to be reabsorbed and removed by the circulatory system

Question 6

roles of lymphatic system in fluid balance:

Answer 6

• unabsorbed tissue fluid
• lymph formation
• lymph movement
• return to bloodstream
• immune function

Question 7

role of the lymphatic system in fluid balance- unabsorbed tissue fluid

Answer 7

• not all tissue fluid is reabsorbed back into the capillaries. the remaining fluid, along with any cellular debris or pathogens, enters the lymphatic system

Question 9

role of the lymphatic system in fluid balance- lymph formation

Answer 9

the excess tissue fluid, now called lymph, is collected by tiny lymphatic capillaries, which merge to form larger lymph vessels

Question 10

role of lymphatic systems in fluid balance- lymph movement

Answer 10

Through the action of muscle contraction and one-way valves, lymph is transported towards two main lymph ducts: the thoracic duct and the right lymphatic duct.

Question 11

role of the lymphatic system in fluid balance- return to bloodstream

Answer 11

These ducts empty the lymph back into the bloodstream (specifically, at the junction of the jugular and subclavian veins), thus completing the fluid cycle and maintaining fluid balance in the body.

Question 12

role of the lymphatic system in fluid balance- immune function

Answer 12

The lymphatic system also plays a crucial role in the immune response, as lymph nodes scattered along the lymph vessels filter the lymph and house lymphocytes that respond to pathogens.