Human Anatomy CH 21 Flashcards
(106 cards)
1
Q
What is the main function of the lymphatic system?
A
Return excess tissue fluid to blood vascular system
2
Q
What collects tissue fluid?
A
Lymphatic vessels
3
Q
What is the function of the immune system?
A
Protects our bodies from foreign organisms and confers immunity to disease
4
Q
What are the main components of the immune system?
A
Lymphocytes, lymphoid tissue, and lymphoid organs
5
Q
Where do lymphatic vessels collect tissue fluid from?
A
Loose connective tissue
6
Q
From the loose connective tissue, where is the fluid carried to?
A
Great veins in the neck
7
Q
Once tissue fluid is within lymphatic vessels, what is it called?
A
Lymph
8
Q
Where does lymph flow?
A
Only toward the heart
9
Q
Where do lymphatic vessels collect tissue fluid from? Where does it return it to?
A
From: Tissue fluid and blood proteins
Returns to: Bloodstream
10
Q
What are the smallest lymph vessels?
A
Lymph capillaries
11
Q
Describe 2 characteristics of lymph capillaries
A
- First to receive lymph
- Highly permeable vessel
12
Q
What collects from lymph capillaries?
A
Collecting lymphatic vessels
13
Q
What are scattered along collection vessels?
A
Lymph nodes
14
Q
What collects lymph from collecting vessels?
A
Lymph trunks
15
Q
What empties in the veins of the neck?
A
Lymph ducts
16
Q
List the order of lymphatic vessels (4)
A
- Lymph capillaries
- Collecting lymphatic vessels
- Lymph trunks
- Lymph ducts
17
Q
Lymphatic capillaries are located near?
A
Blood capillaries
18
Q
Where do the lymphatic capillaries receive tissue fluid from (non-specific)? What opens to allow fluid to enter?
A
Connective tissue; minivalves open
19
Q
High permeability of lymphatic capillaries allows entrance of what?
A
Tissue fluid, protein molecules, bacteria, viruses, and cancer cells
20
Q
What are lacteals?
A
Specialized lymphatic capillaries
21
Q
Where are lacteals located?
A
Villi of small intestines
22
Q
What do lacteals receive?
A
Digested fats
23
Q
What is chyle?
A
Fatty lymph
24
Q
What is fatty lymph?
A
Chyle
25
What do collecting lymphatic vessels accompany? What tunics are they composed of?
Blood vessels; same 3 tunics as blood vessels
26
Do lymphatic vessels contain more valves than veins do?
Yes
27
Does the heartbeat help aid the flow of lymph?
No
28
What 3 weaker mechanisms propels lymph?
1. Bulging of skeletal muscles
2. Pulsing of nearby arteries
3. Tunica media of the lymph vessels
29
What is the function of lymph nodes?
Cleanse the lymph of pathogens
30
How many lymph nodes are in the human body?
500
31
Where are the superficial lymph nodes located?
Cervical, axillary, and inguinal regions
32
Where are the deep lymph nodes located?
Tracheobronchial lymph nodes, aortic lymph nodes, iliac lymph nodes
33
What is a Fibrous Capsule?
Capsule surrounding a lymph node
34
What are Trabculae?
Connective tissue strands extending inwards to divide lymph nodes into segments
35
Where does lymph enter and exist lymph nodes?
Enters: Convex aspect of a lymph node through afferent lymphatic vessels
Exits: At the hilum through efferent lymphatic vessels
36
What do collecting lymph vessels converge to form?
Lymph trunks
37
What receives lymph from lower limbs?
Lumbar trunks
38
What receives chyle from digestive organs?
Intestinal Trunk
39
What collects lymph from thoracic viscera?
Bronchomediastinal trunks
40
What receives lymph from upper limbs and thoracic wall?
Subclavian trunks
41
What drains lymph from the head and neck?
Jugular Trunks
42
Where are cisterna chyli located?
Union of lumbar and intestinal trunks
43
Where does the thoracic duct ascend along? What kind of circulation does it empty into?
1. Vertebral bodies
2. Venous circulation
44
What drains three-quarters of the body?
Thoracic duct
45
What duct is at the junction of the left internal jugular and left subclavian veins?
Thoracic duct
46
What duct empties into the right internal jugular and subclavian veins?
Right Lymphatic Duct
47
What are the 2 main functions of the immune system?
1. Recognize specific foreign molecules
2. Destroy pathogens effectively
48
What are the key cells of the immune system? What can it include?
1. Lymphocytes
2. Lymphoid tissue and lymphoid organs
49
Name all 6 lymphoid organs
1. Lymph Nodes
2. Spleen
3. Thymus
4. Tonsils
5. Aggregated lymphoid nodules
6. Appendix
50
What do infectious organisms trigger?
Inflammatory response
51
After an inflammatory response is triggered, what happens to invading organisms?
Attacked by macrophages, then lymphocytes
52
What is the function of a lymphocyte?
Must be able to effectively recognize a specific foreign molecule
53
What are antigens?
Any molecule that induces a response from a lymphocyte
54
What are the 2 main classes of lymphocytes?
1. B Lymphocytes
2. T Lymphocytes
55
What do Cytotoxic T Lymphocytes do? What are the 4 steps to this process?
Attack foreign cells directly
1. Bind to antigen-bearing cells
2. Perforate cell membrane
3. Signal cell to undergo poptosis
4. Destroy virus-infected cells and some cancer cells
56
What lymphocytes become plasma cells?
B lymphocytes
57
What is another “name” for Helper T and Cytotoxic T Cells?
Helper T: CD4+
Cytotoxic T: CD8+
58
What do B lymphocytes primarily respond to?
Bacteria and bacterial toxins
59
What does plasma cells do? What do they secrete?
1. Mark cells for destruction by macrophages
2. Secretes antibodies
60
Where do lymphocytes originate from?
Bone marrow
61
Which lymphocytes travel to the thymus gland? Which lymphocytes stay in the bone marrow?
1. T lymphocytes
2. B lymphocytes
62
What are 4 characteristics/qualities of activated lymphocytes?
1. Are able to recognize a unique antigen
2. Gain immunocompetence
3. Travel through the bloodstream to meet and bind to a specific antigen
4. Can proliferate rapidly
63
When a lymphocyte is activated, what presents the lymphocyte its antigen?
Macrophage or dendritic cell
64
T and B lymphocytes both produce clones of what?
1. Effector lymphocytes
2. Memory cells
65
What do effector lymphocytes do?
Respond immediately to infectious microorganisms, then die
66
What do memory cells do?
1. Waits until the body encounters the antigen again
2. Prevents subsequent infections of the same illness
67
What kind of cells are the basis for acquired immunity?
Memory cells
68
What tissue is the most important tissue of the immune system?
Lymphoid Tissue
69
What are the two “general” locations that lymphoid tissue can be found?
1. Mucous membrane of digestive, urinary, respiratory, and reproductive tracts
2. Lymphoid organs (except thymus)
70
What does MALT stand for?
Mucosa associated lymphoid tissue
71
What are the 2 primary lymphoid organs?
1. Bone marrow
2. Thymus
72
What are the 3 secondary lymphoid organs?
1. Lymph nodes, spleen, tonsils
2. Aggregated lymphoid nodules
3. Appendix
73
What are the 2 functions of the lymphoid organs?
1. Gather and destroy infectious microorganisms
2. Store lymphocytes
74
What is the site in which immature lymphocytes develop into T lymphocytes?
Thymus
75
When in a human lifespan is the thymus most active?
Childhood
76
What does the thymus secrete?
Thymic hormones
77
With age, functional thymus tissue __________. What is the percentage of tissue that’s left?
1. Atrophies
2. 5%
78
What is the thymus composed of?
Cortex and medulla
79
What does the medulla of thymus contain?
Thymic corpuscles
80
How does the thymus differ from other lymphoid organs?
1. Functions strictly in lymphocyte maturation
2. Arises from epithelial tissue
81
What are the 3 functions of lymph nodes?
1. Lymph percolates through lymph sinuses
2. Most antigenic challenges occur in lymph nodes
3. Antigens destroyed and activate B and T lymphocytes
82
What is the largest lymphoid organ?
Spleen
83
What are the 2 main blood-cleansing functions of the spleen?
1. Removal of bloodborne antigens
2. Removal and destruction of old or defective blood cells
84
Where is the site of hematopoiesis in the fetus?
Spleen
85
Where is the site of B cell maturation into plasma cells?
Spleen
86
What are 2 NON-blood-cleansing functions of the spleen?
1. Storage of platelets
2. Phagocytosis of bacteria and worn-out RBCs, WBCs, and platelets
87
What are the two “pulps”? Where are they found?
1. White pulp
2. Red pulp
3. Spleen
88
What surrounds the white pulp?
Red pulp
89
What is the red pulp composed of? What is it responsible for (function)?
1. Venous sinuses
2. Splenic cord
3. Responsible for disposing of worn-out RBCs
90
What is the white pulp made of? What are its 2 functions?
1. Thick sleeves of lymphoid tissue
2. Bloodborne antigens are destroyed as they activate the immune response
3. Provides immune function of the spleen
91
What are the simplest lymphoid organs?
Tonsils
92
What are the 4 groups of tonsils?
1. Palantine tonsil
2. Lingual tonsil
3. Pharyngeal tonsil
4. Tubal tonsils
93
How are the tonsils arranged and what is their function?
Arranged in a ring to gather and remove pathogen
94
What are the tonsils made out of? What is this consisted of?
Lamina propria, consists of MALT
95
What is abundant in the walls of intestines?
MALT
96
What do aggregated lymphoid nodules and appendix do?
Fight against invading bacteria
97
What is the appendix?
Tubular offshoot of the cecum
98
What is located in the distal part of the small intestine?
Aggregated lymphoid nodules (Peyer’s patches)
99
What is leakage of fatty lymph into the thorax?
Chylothorax
100
What is the inflammation of a lymph vessel?
Lymphangitis
101
What is a viral disease caused by the Epstein-Barr virus that attacks B lymphocytes?
Mononucleosis
102
What is cancer of the lymph nodes?
Hodgkin’s Lymphoma
103
What is uncontrolled multiplication and metastasis of undifferentiated lymphocytes?
Non-Hodgkin’s Lymphoma
104
Where do lymphatic vessels and lymphatic nodes develop from?
Lymphatic sacs
105
What arises from mesodermal mesenchyme?
Spleen, lymph nodes, and MALT
106
Where does the thymus originate from?
Outgrowth of the endoderm
