Lymphatics

Question 1

Primary lymphoid organs? functions?

Answer 1

Red bone marrow & Thymus: sites of B & T cell maturation

Question 2

Secondary lymphoid organs?

Answer 2

lymph nodes, spleen, tonsils, appendix, intestinal follicles:
where mature lymphocytes first encounter their antigens (toxins/foreign bodies) and become activated

Question 3

What structures filter lymph?

Answer 3

lymph nodes

Question 4

gross structure of a lymph node?

Answer 4

• dense fibrous capsule
• trabeculae (for compartmentalising)
• stroma of reticular CT

Question 5

Lymph node functions?

Answer 5

• House lymphocytes and macrophages
• site of immune system activation
• Filtering of lymph (micro organisms and debris)

Question 6

Nodal circulation?

Answer 6

Lymph flows into the node through numerous afferent lymph vessels (convex side)

Lymph moves through the subcapsular sinus towards the medulla

Flow occurs through medullary sinuses

Exits via efferent lymph vessels
Located at hilum (indented region on concave side)

Question 7

Spleen intraperitoneal or retroperitoneal?

Answer 7

intraperitoneal - surrounded by visceral peritoneum except for the hilum (entro of splenic aa & vv)

Question 8

4 x splenic compressions?

Answer 8

stomach, kidney, colon, pancreas

Question 9

2 peritoneal ligaments attaching to the hilum of the spleen?

Answer 9

gastrosplenic & splenorenal ligaments

Question 10

What sits anterior to the spleen?

Answer 10

stomach (connected via gastrosplenic ligament

Question 11

What sits posterior to the spleen?

Answer 11

diaphragm

Question 12

What sits inferior to the spleen?

Answer 12

left colic flexure

Question 13

What sits medial to the spleen?

Answer 13

left kidney (connected via the splenorenal ligament)

Question 14

Red pulp?

Answer 14

Where old RBC’s and bloodborne pathogens are destroyed

- lots of RBC’s and macrophages that engulf them

Question 15

White pulp?

Answer 15

site of immune functions:

mainly lymphocytes suspended in reticular fibres

Question 16

Spleen arterial supply?

Answer 16

splenic artery (celiac trunk)

Question 17

Spleen venous drainage?

Answer 17

splenic vein (formed by several branches emerging from the hilum and joined by the IMV before uniting with the SMV to form the portal vein

Question 18

Spleen nerve supply?

Answer 18

SYMP: abdominopelvic splanchnic

PARA:

Question 19

Pathway of lymphatic flow?

Answer 19

• lymphatic capillaries drain interstitial spaces (once fluid enters these it is termed lymph
• lymphatic collecting vessels (sup vessels drain into deep vessels, which follow arteries)
• lymphatic trunks (formed by large collecting vessels)
• lymphatic ducts: (thoracic & Rt lymphatic ducts)

Question 20

Where does the thoracic duct enter the venous system?

Answer 20

Junction of the Lt IJV & Lt subclavian vein

Question 21

Where does the Rt lymphatic duct enter the venous system?

Answer 21

At the junction of Rt IJV and Lt subclavian veins

Question 22

location of cisterna chyli?

Answer 22

inferior end of the thoracic duct, in the retrocrural space to the Rt of the abdominal aorta

Question 23

3 factors influencing the flow of lymph?

Answer 23

• smooth muscle contractions
• pressure on vessels by skeletal muscle and movement of viscera
• pressure changes in thorax during respiration

Question 24

different types and functions of lymphocytes?

Answer 24

T cells: ~75% - cellular adaptive immunity

B cells: humoral adaptive immunity

Natural killer cells: innate immunity

Question 25

Types and functions of auxillary immune cells?

Answer 25

Macrophages: widely distributed in lymphoid organs. Dendritic cells (mobile antigen-presenting cells)

Question 26

Macrophage functions?

Answer 26

- phagocytosis, - enhancement of inflammatory response - presentation of of antigens to T cells

Question 27

Dendritic cell functions?

Answer 27

mobile antigen-presenting cells, possess cellular extensons (hence dendritic name) that capture antigens and engulf them (phagocytosis). They also migrate to lymph nodes and present antigens to naïve lymphocytes which initiates an adaptive immune response

Question 28

Reticular cells?

Answer 28

supporting cells tha are fibroblast-like that produce CT stroma for lymphoid tissue

Question 29

function of lymphoid tissue?

Answer 29

- proliferation site for lymphocytes | - surveillance point for lymphocytes and macrophages

Question 30

Differentiate diffuse lymphoid tissue from lymphoid follicles?

Answer 30

Diffuse lymphoid tissue • Loose arrangement of lymphoid cells & reticular fibres • Occur in most organs of the body • e.g. lamina propria of the GIT Lymphoid follicles • Solid, spherical bodies consisting of tightly packed lymphoid cells & reticular fibres • Have germinal centres of proliferating B lymphocytes • Form part of lymphoid organs

Question 31

differentiate the roles of primary and secondary lymphoid organs

Answer 31

Primary: provide sites for T and B cell maturation Secondary: are where lymphocytes encounter their first antigens and become activated

Question 32

Differentiate the terms lymphadenopathy and lymphadenitis

Answer 32

Lymphadenopathy: the palpable enlargement of a lymph node, generally due to infections (75%) the other 25% due to significant underlying diseases such as glandular fever, lymphoma, leukameia, HIV Lymphadenitis: lymphadenopathy with pain and other signs of inflammation

Question 33

classification of lymphadenopathy:

Answer 33

Localised: present in 1 body area - Usually reflect pathology in region of drainage Generalised: present in 2 or more non-contiguous nodal groups - Generally due to significant underlying disease

Question 34

5 causes of splenomegaly

Answer 34

- Infection: glandular fever, TB, syphilis - Portal HTN: cirrhosis, cardiac failure - Lymphoid disorders: leukameia, lymphoma, multiple myeloma - RBC disorders: thalassaemia - Inflammatory conditions: rheumatoid arthritis

Question 35

Clinical features associated with splenomegaly

Answer 35

swelling/asymmetry of the abdominal contour dragging sensation in the LUQ increased feelings of fullness after eating

Question 36

What is glandular fever?

Answer 36

an acute infection of B lymphocytes with the EBV (epstein Barr virus)

Question 37

How is Glandular fever transmitted?

Answer 37

saliva and human contact

Question 38

Clinical features of glandular fever

Answer 38

30-50 day incubation period, - fever, sore throat, cervical lymphadenopathy, fatigue - long term/progression: generalised lymphadenopathy, splenomegaly, hepatomegaly

Question 39

What is leukaemia?

Answer 39

proliferation of malignant leucocytes in the bone marrow, in which overcrowding causes malignant cells to spill into the blood

Question 40

signs of leukamia

Answer 40

rapid onset: <3 months: | anaemia, decreased WBC, bleeding tendencies, bone pain

Question 41

what is lymphoma?

Answer 41

proliferation of malignant lymphocytes in the lymphatic system and the formation of discrete tumours

Question 42

what is multiple myeloma?

Answer 42

proliferation of malignant plasma cells in the bone marrow

Question 43

What name is given to the tumour formed in multiple myeloma?

Answer 43

Plasmacytomas: discrete tumours within the bone, which release osteolytic cytokines which destroy the overlying cortical bone

Question 44

What type of cells are targeted by HIV? What implications does this have for the normal functioning of the body?

Answer 44

T cells: these are immune cells which are responsible for making 75% of the circulating lymphocytes, which reduces our cellular adaptive immunity. HIV predisposes life-threatening infections and malignancies as the bodies ability to fight infections ids depleted