Session 1 - Lymphatic system Flashcards Preview

Semester 3 - Infection > Session 1 - Lymphatic system > Flashcards

Flashcards in Session 1 - Lymphatic system Deck (39)
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1
Q

What does the lymphatic system consist of?

A
  • Lymphatic capillaries and vessels

* Lymphoid tissues and organs

2
Q

What is the function of the lymphatic system?

A
  • Innate immunity
  • Adaptive immunity
  • The allergic response
3
Q

What is the purpose of lymphatic capillaries and vessels?

A

• Fluid moves out of the tissue fluid and blood and needs to be reabsorbed

4
Q

What are lymphatic capillaries and vessels?

A

• A network of vessels that assist in circulating fluids

5
Q

What are the functions of lymphatic capillaries and vessels?

A

• Transport excess fluid away from interstitial spaces

6
Q

How is the lymphatic system different from the CVS?

A

• Lymphatic system moves in a one way direction

7
Q

Describe the structure of the lymphatic capillaries

A
  • Tiny closed end vessels consisting of simple squamous epithelium
  • More permeable than blood vessels as the lack a basement membrane
8
Q

Describe the structure of lymphatic vessels

A
  • Resemble small veins

* One way valves

9
Q

How is lymph pumped around lymphatic vessels

A
  • Contraction of surrounding skeletal muscle
  • Periodic contraction of smooth muscle in lymphatic vessel wall
  • Pressure changes in the chest during breathing
10
Q

How are lymphatic vessels similar to veins?

A

• One way valves

11
Q

How are lymphatic vessels different from veins?

A

• No “pump”

12
Q

What do lymphatic vessels converge and empty into?

A
  • The right lymphatic duct

* The thoracic duct

13
Q

Where does the right lymphatic duct drain from and where does it empty?

A

• Drains lymph from upper right limb and right half of head, neck and chest, and empties into subclavian vein

14
Q

Where does the thoracic duct drain from and where does it empty?

A

• Drains from rest of body (other than right lymphatic duct) and empties into left subclavian vein

15
Q

What are the four lymphoid organs?

A
  • Lymph nodes
  • Tonsils
  • Spleen
  • Thymus gland
16
Q

What is a lymph node?

A

• Rounded structures, distributed along the lymphatic vessels

17
Q

What is the structure of a lymph node?

A

• Cortex and medulla

18
Q

Describe the cortex of a lymph node

A
  • Outer part

* Follicles with germinal centre, containing dividing lymphocytes

19
Q

Describe the medulla of a lymph node

A
  • Inner part

* Contains phagocytic macrophages

20
Q

What are the 4 lymph nodes which are important clinically?

A
  • Inguinal lymph nodes (groin)
  • Axillary lymph nodes
  • Cervical lymph nodes (neck)
  • Aortic chain lymph nodes
21
Q

What are the three main functions of the lymphatic system?

A
  • Fluid balance
  • Fat absorption
  • Defence
22
Q

How much fluid moves form blood capillaries to intersitial space a day?

A

30L

23
Q

How many litres of fluid enter lymphatic vessels from blood capillaries?

A

3L

24
Q

What does the lymphatic system do to fat?

A

• Absorbs it from the digestive tract

25
Q

What is fat absorbed into in the lymphatic system?

A

• Lacteals (special lymph vessels) located in lining of small intestine. Fat enters lymphatic and then venous circulation

26
Q

What is chyle?

A

• Lymph that appears milky in appearance due to fat

27
Q

How is the lymphatic system responsible for defence?

A
  • Removal of organisms and foreign substances from the lymph

* Activation of the immune system

28
Q

What lymphadenopathy?

A

• Collective term for a lymph node enlargement

29
Q

What is lympahdenitis?

A

• Swollen, painful node responding to foreign antigen

30
Q

How is a lymph node swollen due to cancer different from one swollen by infection?

A

• Lymph node firm and usually painless

31
Q

What are the tonsils?

A

• Small masses of lympoid tissue around pharynx

32
Q

What is the function of the tonsils?

A

• Trap and remove bacteria and other foreign materials

33
Q

What is tonsilitis caused by?

A

• The congestion of bacteria

34
Q

What is the spleen?

A
  • Largest lymphatic organ

* Contains large amount of circulating blood, due to sinuses

35
Q

What two tissues is the spleen made up of?

A

• Red pulp and white pulp

36
Q

What is red pulp in the spleen?

A
  • Receives arterial blood which passes into venous sinuses

* Lined by macrophages which removes old red cells and recycles haem

37
Q

What is white pulp in the spleen?

A
  • T and B cell compartments with macrophages and other immune cells
  • Recognise and remove pathogens
  • Activates T cells and B cells
38
Q

How does the thymus vary over lifetime?

A
  • Larger in infancy and puberty, before shrinking in adulthood
  • Replaced by fat and connective tissue in elderly
39
Q

What is the function of the Thymus?

A
  • Site of T lymphocyte production

* Secretes hormones called thymosins