Midterm Lymphatic and Immune

Question 1

Lymphatic system roles

Answer 1

• drain interstitial fluid
• help carry out immune responses
• Transport dietary fats

Question 2

Interstitial fluid drainage

Answer 2

• HYDOSTATIC PRESSURE-> leakage of capillaries -> fluid in interstitial space -> 15% reabsorbed by lymph system (& 85% reabsorbed by blood vessels)
• lymphatic system drains excess fluid back into blood via vessels, trunks, and ducts

Question 3

Absorption of Dietary fats

Answer 3

vessels of lymph system- LACTEALS- transport lipids and fat soluble vitamins that are absorbed by GI

Question 4

Lymph capillaries

Answer 4

• aka terminal lymphatics (or lacteals in SI)
• where interstitial fluid enters to become lymph
• interlaced throughout whole body and around blood vessels

Question 5

Lacteals

Answer 5

• in SI
• one layer endothelial cells with flaps at end to allow/ prevent back flow
• transport dietary lipids & lipid vitamins
• dietary triglycerides + other lipid and proteins enter lacteals and = CHYLE
• Chyle-> through lymph system-> into liver -> into bloodstream

Question 6

how does lymph get around body without active pump (like heart)

Answer 6

• movement of body
• contraction of skeletal muscle during body movement
• breathing movements
• one way semilunar valves throughout vessels keeps them moving in the right direction

Question 7

lymphatic vessels eventually merge to form____?

Answer 7

Lymphatic Trunks

-lumbar, intestinal, jugular, subclavian, bronchomediastinal

Question 8

left vs right lymphatic ducts:

Answer 8

right: only upper right
left: rest of body aka THORACIC DUCT
located at junction of jugular and subclavian veins in neck

Question 9

flow through lymph structures: order

Answer 9

interstitial fluid-> lymph capillaries->lymph vessels-> lymph nodes-> lymph trunks -> lymph ducts ->subclavian veins

Question 10

primary lymphoid organs

Answer 10

Red bone marrow
thymus gland
-in immunocompetent people lymphocytes will develop in these organs until they are part of an immune response

Question 11

Red bone marrow and lymphocytes

Answer 11

B cell undergoes almost all maturation and development here

T cell begins development here- then goes to thymus gland for rest of maturation

Question 12

Thymus

Answer 12

between aorta and sternum

outer cortex has large number of t cells maturing

Question 13

Major histocompatibility complex

Answer 13

• MHC
• presented on surface of plasma membrane
• prevent from attacking self antigens, so focus is on harmful antigens

Question 14

Secondary Lymphoid Organs

Answer 14

Lymph nodes
spleen
lymphatic nodules (ex: tonsils)

Question 15

Lymph node

Answer 15

• bean shaped
• cleanse the lymph of pathogens and debris as the lymph travels through the sinuses
• major routes: afferent lymphatic vessels
• fluid leaves vessels via efferent lymphatic vessels

Question 16

spleen: Pulp anatomy and functions

Answer 16

-largest single mass of lymphatic tissue
-2 main components within:
Red pulp: mainly rbc, filters the blood (phagocytize RBCs) and stores platelets
White pulp: mainly lymphatic tissue, mounts adaptive B and T cell responses in the body

Question 17

Lymphoid nodules

Answer 17

• Dense cluster of lymphocytes without capsule
• In respiratory and digestive tracts because they are routinely exposed to environmental pathogens
• ex: tonsils which are on inner layer of pharynx, important for dev of oral immunity towards common pathogens

Question 18

2 immune system mechanisms and their functions

Answer 18

Innate: rapid but nonspecific
Adaptive: slower in dev. with initial infection to specific pathogen, but highly specific & effective

Question 19

Innate defense details

Answer 19

1. Barrier defense: prevent pathogens from entering body, skin and mucous
2. Internal defense mechanisms: phagocytes, Natural killer cells, inflammation, antimicrobial proteins, fever