The Lymphatic and Immune Systems (Q3,P7) Flashcards
1
Q
Main structures of the lymphatic system
A
Lymphatic vessels
2
Q
Main components of the immune system
A
- Lymphocytes
- Lymphoid tissue
- Lymphoid organs
3
Q
Lymphatic vessels
A
- collect lymph from loose connective tissue
- Carry fluid to great veins in the neck
- Fluid flows only toward the heart
4
Q
Orders of Lymphatic Vessels (Smallest to Largest)
A
- Lymph Capillaries
- Lymphatic Collecting Vessels
- Lymph Nodes
- Lymph Trunks
- Lymph Ducts
5
Q
Lymph capillaries
A
- smallest lymphatic vessel
- first receive lymph
6
Q
Lymphatic collecting vessels
A
collect from lymph capillaries
7
Q
Lymph nodes
A
scattered along collecting vessels
8
Q
Lymph trunks
A
collect lymph from collecting vessels
9
Q
Lymph ducts
A
empty into veins of the neck
10
Q
Functions of Lymphatic Vessels
A
- Collect excess tissue fluid and blood proteins
- Return tissue fluid and blood proteins to bloodstream
11
Q
Lymph Capillaries
A
- Located near blood capillaries
- Receive tissue fluid from connective tissue
- Increased volume of tissue fluid
- Minivalve flaps open and allow fluid to enter
- Highly permeability allows:
Uptake of tissue fluid and the entrance of bacteria, viruses, and cancer cells
12
Q
Lacteals
A
- specialized lymphatic capillaries
- Only in the small intestines;
- that receive a fatty lymph called “chyle
13
Q
Lymphatic Collecting Vessels
A
- Accompany blood vessels
- Composed of the same three tunics as blood vessels
- Contain more valves:Helps direct the flow of blood
- Lymph is propelled by:Bulging of skeletal muscles, Pulsing of nearby arteries, and Tunica media of the lymph vessels
14
Q
Lymph Nodes
A
- Cleanse the lymph of pathogens
- Human body contains approximately 500
- Lymph nodes are organized in clusters
- Located along lymphatic vessels
15
Q
Lymph Trunks
A
- Lymphatic collecting vessels converge
- Five major lymph trunks: Lumbar trunks, Intestinal trunk, Bronchomediastinal trunks, Subclavian trunks, Jugular trunks
16
Q
Lumbar trunks
A
- Type of Lymph Trunk
- receives lymph from lower limbs
17
Q
Intestinal Trunk
A
- Type of Lymph Trunk
- receives chyle from digestive organs
18
Q
Bronchomediastinal Trunks
A
- Type of Lymph Trunk
- collects lymph from thoracic viscera
19
Q
Subclavian Trunks
A
- Type of Lymph Trunk
- receive lymph from upper limbs and thoracic wall
20
Q
Jugular Trunks
A
- Type of Lymph Trunk
- drain lymph from the head and neck
21
Q
Cisterna chyli
A
- Type of Lymph Duct
- located at the union of lumbar and intestinal trunks
22
Q
Thoracic Duct
A
- Type of Lymph Duct
- ascends along vertebral bodies
- Empties into venous circulation
- Junction of left internal jugular and left subclavian veins
- Drains three quarters of the body (all but upper right)
23
Q
Right Lymphatic Duct
A
- Type of Lymph Duct
- Empties into right internal jugular and subclavian veins
24
Q
The Immune System
A
- Recognizes specific foreign molecules
- Destroys pathogens effectively
- Key cells in the immune system: lymphocytes
- Also includes lymphoid tissue and lymphoid organs
25
Lymphocytes
A type of immune cell that is made in the bone marrow and is found in the blood and in lymph tissue
- Macrophages are released, then lymphocytes
- 2 Types: B Lymphocytes and Cytotoxic T Lymphocytes
26
B lymphocytes
- become plasma cells
- Secrete antibodies (apart of blood plasma and lymphatic system)
27
Cytotoxic T lymphocytes
Destroy antigen-bearing cells
28
Lymphocyte Activation
- **Lymphocytes originate in red bone marrow**
- Some travel to the thymus gland and mature in the thymus gland (endocrine gland), and become T lymphocytes
- Some stay in bone marrow and mature in the bone marrow
B lymphocytes
29
How are T and B Cells activated
Able to recognize a unique antigen – B and T cells are activated by an antigenic encounter
30
What do T and B Cells Produce
1. Effector Lymphocytes
2. Memory Lymphocytes
31
Effector lymphocytes
short-lived, attack immediately. (first responders)
32
Memory lymphocytes
- wait until body encounters their antigen again. (attack later if needed)
- Basis of acquired immunity
33
Memory lymphocytes
- wait until body encounters their antigen again. (attack later if needed)
- Basis of acquired immunity
34
Lymphoid Tissue
- Most important tissue of the immune system
- Two general locations:
1. Mucous membranes of Digestive, urinary, respiratory, and reproductive tracts (Mucosa-associated lymphoid tissue (MALT))
2. Lymphoid organs
35
Lymphoid Organs
- Designed to gather and destroy infectious microorganisms
- Thymus, Lymph Nodes, Spleen, Tonsils
36
Thymus
- Immature lymphocytes develop into T lymphocytes
- Secretes thymic hormones
37
Lymph Nodes
- Most antigenic challenges occur in lymph nodes (where b and t lymphocytes go)
Destroy Antigens – and activate B and T lymphocytes
38
Spleen
- **Largest lymphoid organ**
- Two main blood-cleansing functions: 1. Removal of blood-borne antigens 2. Removal and destruction of old/defective blood cells
- Site of hematopoiesis (blood cell formation) in the fetus (because babies don’t have enough bone marrow to make blood)
39
Tonsils
- Simplest lymphoid organs
- **Four groups of tonsils: Palatine, lingual, pharyngeal, and tubal tonsils**
- Arranged in a ring to gather and remove pathogens
- Underlying lamina propria consists of MALT
- Palatine tonsils are the largest and most often infected in childhood
40
Aggregated Lymphoid Nodules and the Appendix
- MALT – abundant in walls of intestines
- Fight invading bacteria
- Generate a wide variety of memory lymphocytes: Peyer's Patches, Appendix
41
Peyer’s patches
- Aggregated lymphoid nodules
- Located in the distal part of the small intestine
- Generate a wide variety of memory lymphocytes
42
Appendix
- tubular offshoot of the cecum
- Generate a wide variety of memory lymphocytes
