Lymphatic System

Question 1

What is the lymphatic system?

Answer 1

Network of vessels that penetrate nearly every tissue of the body and a collection of tissues and organs that produce immune cells

Question 2

What are the three functions of the lymphatic system?

Answer 2

Fluid recovery, Immunity, Lipid absorption

Question 3

How does the lymphatic system recover fluid?

Answer 3

Absorbs plasma proteins and excess fluids that come from the blood capillaries and puts it back into the blood stream

Question 4

What happens when the lymphatic system does not recover fluid?

Answer 4

The circulatory system does not have enough blood and it can lead to edema

Question 5

What is elephantiasis?

Answer 5

mosquito-borne roundworms infect lymph nodes blocking the flow of lymph, causing edema

Question 6

How does the lymphatic system provide immunity?

Answer 6

fluids from all capillary beds are filtered through lymph nodes, which is where immune cells wait

Question 7

How does the lymphatic system absorb lipids?

Answer 7

The small intestine has lymphatic vessels called lacteals that absorb lipids

Question 8

What is the most common type of lipid absorbed by the lymphatic system?

Answer 8

long chain lipids that do not fit in the blood capillaries

Question 9

What is lymph?

Answer 9

clear, colorless fluid, similar to plasma but contains less proteins

Question 10

What are lymphatic capillaries?

Answer 10

closed at one end and tethered to surrounding tissue by protein filaments

Question 11

What do lymphatic capillaries do?

Answer 11

allow lymph fluid, small proteins, and bacteria entrance into lymphatic capillary

Question 12

Where are there not lymphatic capillaries?

Answer 12

bones, teeth, bone marrow, nervous system

Question 13

What happens when interstitial pressure is high?

Answer 13

Valve like flaps on lymphatic capillaries open (they close when pressure is low)

Question 14

What are the characteristics of lymphatic vessels?

Answer 14

low pressure, larger ones are composed of three layers

Question 15

What are the three layers of lymphatic vessels?

Answer 15

tunica interna (endothelium valves), tunica media (elastic fibers, smooth muscle), tunica externa (thin external layer)

Question 16

Route of Lymph Flow

Answer 16

lymphatic capillaries –> collecting vessels –> lymphatic trunks –> collecting ducts

Question 17

What do collecting vessels do?

Answer 17

course through many lymph nodes

Question 18

What do lymphatic trunks do?

Answer 18

drain to major portions of body

Question 19

What do collecting ducts do?

Answer 19

right lymphatic duct and thoracic duct

Question 20

Where does the route of lymph flow end?

Answer 20

The clavicles

Question 21

Where does the right lymphatic duct drain?

Answer 21

drains lymph from the right arm, right side of head and thorax; empties into the right subclavian vein

Question 22

Where does the thoracic duct drain?

Answer 22

left subclavian vein and receives lymph from the diaphragm, head, neck and thorax

Question 23

What is the difference between the right lymphatic duct and the thoracic duct?

Answer 23

The thoracic duct is larger and longer and begins as a sac in the abdomen called cisterna chyli

Question 24

Where does all lower extremity lymph get dumped?

Answer 24

The left subclavian

Question 25

What are the mechanisms of flow for lymph transport?

Answer 25

skeletal muscle pump, pressure changes in thorax during breathing, artery pulsations, and rhythmic vessel smooth muscle contraction

Question 26

What do artery pulsations do?

Answer 26

Helps increase lymphatic vessel pressure

Question 27

What are lymphocytes also called?

Answer 27

T and B cells

Question 28

What are lymphocytes?

Answer 28

Main WBC warriors of immune system, arise in red bone marrow, protect the body against antigens

Question 29

What are T-cells?

Answer 29

mature in thymus (t=thymus dependent) and once activated they manage the immune response, attack/destroy infected cells

Question 30

What are B cells?

Answer 30

cells that produce plasma cells that secrete antibodies in blood or other fluids which mark antigens for destruction

Question 31

What do macrophages do?

Answer 31

phagocytize foreign substances and activates T-cells

Question 32

What do dendritic cells do?

Answer 32

capture antigens bringing them back to lymph nodes

Question 33

What do dendritic cells look like?

Answer 33

spiny

Question 34

What do reticular cells do?

Answer 34

produce spider web-like fibers called stroma; network that supports other cell types in lymphoid organs and tissues

Question 35

How many lymph nodes are in the body?

Answer 35

hundreds

Question 36

Which lymph nodes are close to the surface?

Answer 36

cervical, inguinal, axillary

Question 37

Which lymph nodes are deep in cavities?

Answer 37

thoracic, pelvic, abdominal region

Question 38

What is the structure of lymph nodes?

Answer 38

most are bean shaped and less than an inch

Question 39

What surrounds nodes?

Answer 39

Dense fibrous capsules from which CT strands called trabeculae extend inward dividing the node into compartments

Question 40

What is lymph node flow?

Answer 40

receives lymph through afferent lymphatic vessels that lead into the cortex and medulla sinuses, while lymph leaves node through 1 to 3 efferent lymphatic vessels

Question 41

Function of lymph nodes

Answer 41

only organ that filters lymph

Question 42

What happens with in the filtration of the lymph nodes?

Answer 42

macrophages remove/eat microbes

Question 43

How is the immune system activated?

Answer 43

lymphocytes attack foreign antigens and fight things

Question 44

What is lymphadenitis?

Answer 44

swollen, painful node that is responding to a foreign invader (antigen)

Question 45

What happens with cancer of the lymph nodes?

Answer 45

cancer cells can break loose, enter lymphatic capillaries, and lodge in the nodes

Question 46

What do tonsils do?

Answer 46

Guard entrance to pharynx against ingested pathogens

Question 47

What are tonsillar crypts?

Answer 47

the epithelium of the tonsils that has deep pits lined with lymphatic nodules

Question 48

What happens when pathogens enter the tonsillar crypts?

Answer 48

They encounter lymphocytes

Question 49

Where are the lingual tonsils located?

Answer 49

both sides of the tongue

Question 50

Where are the tubal tonsils located?

Answer 50

surround the openings of the auditory tubes into the pharynx

Question 51

Where is the pharyngeal tonsil located?

Answer 51

on the wall of pharynx just behind the nasal cavity

Question 52

Where are the palatine tonsils located?

Answer 52

largest and most often infected of the tonsils in the posterior margin of the oral cavity

Question 53

What is the function of the thymus?

Answer 53

houses developing T lymphocytes and secrete hormones that regulate their later activity

Question 54

What do T lymphocytes do?

Answer 54

during development, are protected from foreign antigens by the blood-thymus barrier until they are mature and enter the blood or lymphatic vessels

Question 55

What is the size of the thymus?

Answer 55

Large in fetuses and shrinks in adult

Question 56

What is the body's largest lymphatic organ?

Answer 56

Spleen (size of the fist)

Question 57

What is red pulp?

Answer 57

consists of sinuses gorged with RBC's

Question 58

What is white pulp?

Answer 58

consists of lymphocytes and macrophages suspended on reticular fibers along the small branches of the splenic artery

Question 59

What is MALT?

Answer 59

mucosa-associated lymphoid tissue

Question 60

What does MALT do?

Answer 60

set of distributed lymphoid tissues strategically located in mucous membranes throughout the body

Question 61

Where are the largest collections of MALT found?

Answer 61

Peyer's patch and appendix

Question 62

What is Peyer's patch?

Answer 62

large clusters of lymphoid follicles, similar to tonsils, found in the wall of distal portion of the small intestine

Question 63

What is the appendix?

Answer 63

Tubular offshoot of the first part of the large intestine that contains a high concentration of lymphoid follicles

Question 64

Where are smaller collections of MALT found?

Answer 64

In the mucosa of the respiratory and genitourinary organs and digestive tract