WEEK 2 (PART 3)

Question 1

What happens to plasma as blood flows through capillaries?

Answer 1

Filters into interstitial spaces.

Question 2

Where does most interstitial fluid eventually drain?

Answer 2

Lymphatic vessels

Question 3

What would happen without a lymphatic system?

Answer 3

Excess interstitial fluid buildup causing tissue edema and destruction.

Question 4

Describe the lymphatic system.

Answer 4

Unidirectional closed circulatory system that moves fluid from tissues to blood.

Question 5

What is the fluid called once it enters the lymphatic system?

Answer 5

Lymph

Question 6

What is the structure of a lymphatic capillary?

Answer 6

Single layer of flattened endothelial cells with special junctions for fluid uptake.

Question 7

How are lymphatic capillaries attached to surrounding tissues?

Answer 7

Connective tissue filaments.

Question 8

What happens to lymphatic capillaries?

Answer 8

Coalesce into larger lymphatic vessels (veins).

Question 9

Where does lymph travel after the vessels?

Answer 9

Lymph nodes for filtering and immune system inspection.

Question 10

How do lymphatic vessels generally travel in relation to veins?

Answer 10

Parallel to venous return.

Question 11

What facilitates unidirectional lymph flow?

Answer 11

One-way valves present in lymphatic veins (not capillaries).

Question 12

Why is maintaining plasma protein concentration difficult with lymph loss?

Answer 12

Dietary intake cannot compensate for significant ongoing lymph loss.

Question 13

How do lymphatic vessels form progressively larger structures?

Answer 13

Lymphatic capillaries merge into larger lymphatics, then into even larger vessels.

Question 14

What are the main lymphatic trunks?

Answer 14

Right lymphatic duct and thoracic duct.

Question 15

Where does most of the body’s lymph drain?

Answer 15

Thoracic duct (drains into left subclavian vein).

Question 16

Where does lymph from the upper right quadrant drain?

Answer 16

Right lymphatic duct (drains into right subclavian vein).

Question 17

Is the structure of the right lymphatic duct consistent?

Answer 17

No, variations exist (e.g., three separate ducts instead of one).

Question 18

How does the unique structure of lymphatic vessels allow for fluid and cells to enter?

Answer 18

Special junctions between endothelial cells in lymphatic capillaries.

Question 19

What else enters lymphatic capillaries besides fluid?

Answer 19

Antigen-presenting cells and small antigen molecules.

Question 20

What is the role of lymph flow through lymphatic capillaries?

Answer 20

Delivers lymph contents (including antigens) to lymph nodes.

Question 21

What is the general shape of a lymph node?

Answer 21

Small, bean-like structure.

Question 22

How does lymph enter and leave a lymph node?

Answer 22

• Enters via afferent lymphatic ducts. * Exits via efferent lymphatic ducts.

Question 23

What maintains the structure of a lymph node?

Answer 23

Outer fibrous capsule.

Question 24

Where do efferent lymphatic vessels leave the node?

Answer 24

Hilum (concave area).

Question 25

How does lymph move through a lymph node?

Answer 25

* Seeps through specialized spaces called sinuses. * Drains into the efferent vessel.

Question 26

What ensures one-way lymph flow through lymph nodes?

Answer 26

Tissue valves in afferent and efferent vessels.

Question 27

What is visible inside a lymph node (cut open)?

Answer 27

* Fibrous septa (trabeculae) extending from the capsule inwards. * Cortical nodules with a less dense germinal center.

Question 28

What cell types are found in cortical nodules?

Answer 28

Many subtypes of lymphocytes.

Question 29

What happens to lymph nodes during an infection?

Answer 29

* Germinal centers form. * Increased lymphocyte production and release.

Question 30

Where do B cells mature in a lymph node?

Answer 30

Germinal centers of cortical nodules.

Question 31

What do mature B cells become?

Answer 31

Antibody-producing plasma cells.

Question 32

What is the function of the medulla in a lymph node?

Answer 32

Contains sinuses and medullary cords for further filtration and immune cell activity.

Question 33

What do the sinuses and medullary cords contain?

Answer 33

Reticuloendothelial cells (macrophages) capable of phagocytosis.

Question 34

Do lymph nodes exist singly or in clusters?

Answer 34

Both singly and in clusters.

Question 35

Preauricular lymph nodes

Answer 35

In front of the ear.

Question 36

Submental and submandibular groups

Answer 36

Floor of the mouth.

Question 37

Superficial cervical lymph nodes

Answer 37

Along the sternocleidomastoid muscle in the neck.

Question 38

Axillary lymph nodes

Answer 38

Underarm and upper chest regions.

Question 39

Iliac and inguinal lymph nodes

Answer 39

Pelvis and groin.

Question 40

How does lymph node structure aid phagocytosis?

Answer 40

Sinus channels slow lymph flow, allowing more time for phagocytosis by reticuloendothelial cells.

Question 41

What are the consequences of excessive microorganisms entering lymph nodes?

Answer 41

Overwhelms phagocytes, leading to lymph node infection (adenitis).

Question 42

What are lacteals?

Answer 42

Specialized lymphatic capillaries in intestinal villi that absorb fats and nutrients.

Question 43

What is the milky fluid transported by lacteals called after digestion?

Answer 43

Chyle

Question 44

What does chyle contain?

Answer 44

Absorbed lipids (fats).

Question 45

Where are lipids transported from chyle sent?

Answer 45

To the liver for processing and redistribution.

Question 46

What is the final destination of the processed lipids?

Answer 46

Systemic circulation and storage sites like adipose tissue.

Question 47

How can cancer spread?

Answer 47

Through blood vessels or the lymphatic system.

Question 48

How can cancer cells enter the lymphatic system?

Answer 48

Break away from the tumor and enter lymphatic vessels.

Question 49

What can happen when cancer cells reach lymph nodes?

Answer 49

* Form new tumors. * Block lymph flow.

Question 50

What is a consequence of blocked lymph flow?

Answer 50

Fluid buildup and swelling in the affected area (e.g., arm swelling).

Question 51

How does the structure of lymphatic capillaries facilitate cancer cell migration?

Answer 51

Unique overlapping structure allows for easy entry.

Question 52

Examples of cancers that spread through lymphatics:

Answer 52

* Breast cancer * Gynecological cancers

Question 53

What is secondary lymphoedema?

Answer 53

Swelling caused by blocked lymph flow due to cancer treatment (e.g., mastectomy).