Lymphatic system

Question 1

What four things does the lymphatic system consist of?

Answer 1

-Lymph
-Lymphatic vessels
-Lymphatic tissue
-red bone marrow

Question 2

What are the functions of the lymphatic system?

Answer 2

-drainage of interstitial fluid
-transporting dietary lipids and lipid soluble vitamins (A,D,E,K)
-facilitation of the immune response

Question 3

How does lymph form?

Answer 3

structural relationship between cappilary bed of the blood vascular system and lymphatic cappilaries.

Question 4

Describe hydrostatic pressure

Answer 4

the pushing force exerted by a fluid
~30-10 mmHg between arterial and venous end

Question 5

Describe interstital fluid pressure

Answer 5

slightly negative -3mmHg which contributes to the outward pull of fluid from the cappilaries

Question 6

Describe collodial osmotic pressure

Answer 6

the pulling force created by blood proteins that are too large to pass through the pores of the membrane

~28mmHg in the cappilaries

Question 7

Describe interstital osmotic pressure

Answer 7

is ~8mmHg
-created by a small number of plasma proteins that have leaked into the extracellular tissue space

Question 8

How is blood plasma converted into interstital fluid?

Answer 8

blood hydrostatic pressure pushes blood plasma out of the blood cappilaries to bathe surrrounding tissue.

Question 9

Decribe the role of the protein albumin in the formation of lymph

Answer 9

-albumin is too large to leave the cappilaries and creates an osmotic pressure inside the cappilaries

-the blood osmotic pressure pulls interstital fluid back into blood cappillaries

Question 10

How does drainage of unreturned interstital fluid occur?

Answer 10

-lymphatic cappilaries and lymph vessels

Question 11

how does fluid enter the lymph cappilary?

Answer 11

-one way minivalves
-once inside it is known as lymph

Question 12

Dsecribe the process involved in the drainage of lymph

Answer 12

-lymph cappilaries join to form lymph vessels

-lymph vessels are similar to veins-they have certain internal structures to ensure lymph flows one way

-lymph vessels drain into one of two ducts which return lymph to blood

Question 13

name the two lymph ducts

Answer 13

-right lymphatic duct
-left thoracic duct

Question 14

Describe the fuction of the right lymphatic duct

Answer 14

-drains upper right side of the body and right arm

-returns lymph to the right subclavian vein

Question 15

Describe the function of the left thoracic duct

Answer 15

-drains the rest of the body
-the left thoracic duct begins with the cisterna chyli amd returns lymph to the left subclavian vein

Question 16

describe how lymph drains into the cisterna chyli

Answer 16

-lymph cappilaries in small intestine-lacteals
-lacteals carry fat laden lymph-chyle
-lacteals join together to form vessels
-vessels containing fat laden lymph drain into cisterna chyli

Question 17

Describe the links between the CV and lymphatic system

Answer 17

-plasma forms interstital fluid
-interstital fluid returned to the plasma
-fluid that is not returned to the plasma enters the lymph cappilaries to form lymph
-lymph is returned to the CV

Question 18

What is oedema?

Answer 18

palpable swelling produced by an increase in interstital fluid volume

Question 19

What factors influence oedema?

Answer 19

-increased cappilary filtration pressure
-decreased cappilary colloidal osmotic pressure
-increased cappilary permeability
-obstruction to lymph flow-lympoedema

Question 20

Where can you find lymph nodes?

Answer 20

-pharyngeal region/tonsils
-thymus
-spleen
-Peyers patch in intestine
-appendix

Question 21

What pathway is lymph recieved?

Answer 21

afferent (going towards vessels)

Question 22

What pathway is lymph drained?

Answer 22

efferent (going away from vessels)

Question 23

Describe the structure of lymph nodes

Answer 23

-surrounded by connective tissue capsules

-trabeculae project inwards from capsules forming compartments

-each compartment is made up of reticular cells
between recticular cells are lymphocytes

Question 24

What is the function of recticular cells?

Answer 24

phagocytise unwanted substances

Question 25

What do lymphocytes produce?

Answer 25

antibodies

Question 26

Name some structures in the recticular cells of lobule

Answer 26

-macrophage
-reticular cells on reticular fibres
-lymphocytes
-medullary sinus
-reticular fibers

Question 27

Describe the peyer’s patches

Answer 27

-direction of absorption and possible entry of microorganisms

-nodules also found in mucosa of other tubular structures in respiratory, urinary and reproductive systems

Question 28

What does MALT stand for?

Answer 28

Mucosa
Associated
Lymphoid
Tissue

Question 29

Name the five types of tonsils

Answer 29

2x palatine (either side of the oral cavity)

2x lingual (at the base of the tongue

1x Pharyngeal or adenoid
(on the posterior wall of the nasopharynx)

Question 30

What is the structure if the thymus gland?

Answer 30

-found in the mediastinum above the heart
-surrounded by a connective tissue capsule with inward projecting trabeculae

Question 31

What is the function of the thymus gland?

Answer 31

-produce thymic factor
-thymic factor is important in setting up the immune system and the formation of T lymphocytes

Question 32

Describe age involution of the thymus gland

Answer 32

thymus is largest in childhood
-after childhood the thymus decreases in size

Question 33

where is the spleen located?

Answer 33

left side of abdominal cavity below the diaphragm

Question 34

What is the spleen comprised of?

Answer 34

recticular cells-lymphatic tissue
red pulp
white pulp

Question 35

What is the function of red pulp?

Answer 35

removes worn out platelets and RBCs, stores platelets and produces RBCs in the foetus

Question 36

What is the function of white pulp?

Answer 36

Carries immune funtion and removes blood borne pathogens