7. Lymphatic System

Question 1

Primary Lymphoid Tissues - Lymphocyte

Answer 1

• Thymus

- Bone Morrow

Question 2

Secondary Lymphoid Tissues - Antigen

Answer 2

• Tonsils
• Spleen
• Lymph Nodes
• Peyer’s Patches
• Mucosa-associated Lymphoid Tissue (MALT): located in mucous membrane; site of pathogen entry

Question 3

Function Of Lymphatic System

Answer 3

1. Drain interstitial fluid
2. Transport dietary fats
3. Carry out immune responses

Blood circulation exchanges nutrients, waste and gases between the blood and interstitial fluid

Question 4

How the lymphatic system functions

Answer 4

• Driven by hydrostatic and colloid osmotic pressure
• Blood exits capillary bed at the arterial in and is reabsorbed at the venous end
• Lost Floyd must re-enter the blood to maintain blood volume!

Question 5

Capillary Exchange: Filtration ⬆️

Answer 5

Arterial end net filtration pressure= +10 mm Hg.

Fluid exits Capillery since capillary hydrostatic pressure (35 mm Hg) is greater than blood colloidal osmotic pressure (25 mm Hg)

Question 6

Capillary Exchange: No Net Movement

↕️

Answer 6

Mid capillary net filtration pressure equals zero MMHG.

No net movement of fluid since capillary hydrostatic pressure (25 mm Hg) equals blood colloidal osmotic pressure (25 mm Hg)

Question 7

Capillary Exchange: Reabsorption ⬇️

Answer 7

Venous end net filtration pressure= -7 MM Hg.

Fluid re-enters capillary since capillary hydrostatic pressure (18 mm Hg) is less than blood colloidal osmotic pressure (25 mm Hg)

Question 8

Formation and flow of lymph fluid

Answer 8

• lymph flows only towards the heart
• return excess tissue fluid to the bloodstream
• return leaked protein to the blood
• Carry absorbed fat from the intestine to the blood

Question 9

Lymph Fluid Flow In Stages

Answer 9

Interstitial fluid➡️ lymph capillaries➡️ lymph vessels➡️ lymph trunks➡️ lymph ducts➡️subclavian veins

Question 10

Function of lymph nodes

Answer 10

• Structural bases for the immune system
• Contain lymphoid cells
• 2 basic functions:
  
  1. Filter lymph - macrophages
  2. Immune system activation- lymphocytes

Question 11

Arms of the Immune System:

Innate Defenses

Answer 11

Skin Barriers

• skin
• mucous membranes

Internal Defenses

• Phagocytes
• Natural Killer Cells
• Inflammation
• Antimicrobial Proteins
• Fever

Question 12

Arms of the Immune System:

Adaptive Defenses

Answer 12

Humoral Immunity: B cells

Cellular immunity: T cells

Question 13

Innate Immunity

Answer 13

• Prevent entry of pathogens in foreign materials
• Destroy pathogens and foreign materials
• Activate the adaptive immune system
• Present at birth

Question 14

Innate Response

Answer 14

• Rapid
• Non-specific
• The same every time

Question 15

Acute Inflammation: Tissue Injury

Answer 15

• Remove foreign material/pathogens
• Confine pathogens
• Clear debris
• Prepare for repair

Question 16

Signs of acute inflammation

Answer 16

• Heat
• Redness
• Swelling
• Pain
• +/- Loss of function

Question 17

Adaptive Immunity

Answer 17

• Recognizes foreign substances
• Tolerate “self”
• Amplify inflammatory response

Question 18

The Adaptive Response

Answer 18

• Lags
• Specific
• Systemic
• Memory

Question 19

Humoral Immunity: Active

Answer 19

Naturally Acquired: infection; contact with pathogen

Artificially Acquired: vaccine; dead or attenuated pathogens

Question 20

Humoral Immunity: Passive

Answer 20

Naturally Acquired: antibodies passed from mother to fetus via placenta; or to infant in her milk.

Artificially Acquired: injection of exogenous antibodies (gamma globulin)