Chapter 20 Lymphatics Flashcards
(60 cards)
1
Q
A hematopoietic stem cell will give rise to ______
A
- ertthrocytes
- leukocytes
- platelets
- all of the above
2
Q
Predict the outcome of an overdose of the hormone erythropoietin
A
- The blood viscosity increases to levels that may induce heart attacks or strokes.
- The oxygen-carrying capacity remains unchanged despite elevated red blood cell counts.
- Red blood cell counts remain unchanged, but the number of reticulocytes increases.
- Blood viscosity levels decrease while oxygen-carrying capacity increases.
3
Q
If a patient has pernicious anemia, the inability of the body to absorb vitamin B12 the patient ______
A
- would have reduced blood iron levels
- would have a decreased number of red blood cells
- would have increased levels of hemoglobin
- would not experience any effects on red blood cells
4
Q
Lymphatic system
A
- a network of vessels that absorbs fluid that leaks from the blood into surrounding tissues
- about 3 liters of fluid leak out each day
- if leakage continued unchecked the body would swell with fluid
5
Q
3 parts of the lymphatic system
A
- network of lymphatic vessels (lymphatics)
- lymph- fluid
- lymph nodes, tissues, and organs
6
Q
functions of the lymphatic system
A
- returns interstitial fluid and leaked plasma proteins back to the blood
- once interstitial fluid enters lymphatics, it is called lymph (clear water)
- ONE WAY SYSTEM
- brings fluids back to the heart to reintroduce to the circulatory system
- together with lymphoid organs and tissues, provide the structural basis of the immune system
7
Q
right lymphatic duct and thoracic duct
A
-bring lymphatic fluids to the heart to be reintroduced to the circulatory system
8
Q
lymphatic vessels
A
- one way system
- lymph flows TOWARDS the heart
- lymphatic capillaries
- lymphatic collecting vessels
- lymphatic trunks and ducts
9
Q
lymphatic capillaries
A
- the smallest
- similar to blood capillaries except they are very permeable (take up cell debris, pathogens, and cancer cells)
- endothelial cells overlap to form one-way minivalves
- lacteals- specialized lymph capillaries present in small intestines -> absorb digested fat and deliver fatty lymph (chyle) to the blood
- anchored by filaments to connective tissues
- increased interstitial fluid pressure -> minivalves open -> take in lymph fluid -> bring back to heart
- blind ended tubes in which adjacent endothelial cells overlap each other, forming flaplike minivalves
10
Q
lymphatic collecting vessels
A
- similar to veins except have thinner walls
- more internal valves
- anastomose more frequently
- collecting vessels in the skin travel with superficial veins
- deep collecting vessels travel with arteries
11
Q
anastomose
A
- different structures connect together in the same space
- ex. venous and arterial blood flow collides
12
Q
lymph nodes
A
- collections of lymph structures that follow the lymphatic system
- organized in clusters
- cervical nodes- neck, infection, sickness
- axillary node- armpit, breast cancer
- inguinal nodes- filter blood from the legs
13
Q
lymphatic trunks
A
- formed by the union of the largest collecting ducts
- largest
- paired lumbar
- paired bronchomediastinal
- paired subclavian
- paired jugular trunks
- a single intestinal trunk
- lymphatic capillaries -> collecting vessels -> trunks -> ducts
14
Q
cisterna chyli
A
-bulbous piece
15
Q
lymphatic ducts
A
- lymph is delivered into one of two large ducts
- right lymphatic duct
- thoracic duct
- each empties lymph into venous circulation at the junction of the internal jugular and subclavian veins on its own side of the body
16
Q
right lymphatic duct
A
-drains the right upper arm and the right side of the head and thorax
17
Q
thoracic duct
A
-arises from the cisterna chyli (large sac) and drains the rest of the body
18
Q
what propels blood throughout the body
A
- the heart
- lymph does not have anything pumping it
- lymph system is low pressure
19
Q
lymph transport
A
- lymph is propelled by:
- pulsations of nearby arteries
- contractions of smooth muscle in the walls of the lymphatics
- milking action of active skeletal MM
- pressure changes in the thorax during breathing
- lacks and organ to act as pump, low pressure vessels
20
Q
lymphoid cells
A
- lymphocytes the main warriors of the immunes systems
- two main varieties-
- t cells (t lymphocytes)- thymus, attack interstitial invaders
- b cells (b lymphocytes)- bone marrow, attack outside invaders
21
Q
lymphocytes
A
- t cells and b cells protect against antigens- anything percieved as foreign
- ex. bacteria and their toxins, viruses & mismatched RBCs or cancer cells
- t cells attack and destroy foreign cells
- b cell produce plasma cells which secrete antibodies
22
Q
macrophages
A
- lymphoid cells
- phagocytize foreign substances and help activate t cells
23
Q
dendritic cells
A
- lymphoid cells
- capture antigens and deliver them to lymph nodes
- also activate T cells
24
Q
reticular cells
A
- lymphoid cells
- produce lymphoid tissues stroma (mattress) that supports other cells in lymphoid organs
25
_____ can enter lymphatic capillaries
- bacteria
- large proteins
- interstitial fluid
- all of the above******
- B and C only
26
1. Name the 4 types of lymph vessels and 2. What is the difference between the right lymphatic ducts and the thoracic duct
1. capillaries, collecting vessels, trunks, ducts
2. right lymphatic duct drains right axillary, right upper extremities, right side of face, ... thoracic duct drains everything else
27
B cells
- b lymphocytes)-
- made in bone marrow
- attack outside invaders
- b cells produce plasma cells which secrete antibodies
28
T cells
- t lymphocytes
- made in thymus
- attack interstitial invaders
- attack and destroy foreign cells
29
lymphoid tissues
- houses and provides a proliferation site for lymphocytes
- furnishes a surveillance vantage point
- two types:
- diffuse lymphatic tissue
- lymphatic follicles
30
diffuse lymphatic tissue
- found in every organ in body
- made of loose reticular CT
- larger collections appear in mucous membranes (digestive tract) and lymphoid organs -> where illness can be caused
31
lymphatic follicles (nodules)
- solid, spherical bodies of tightly packed reticular elements and cells
- germinal center composed of dendritic and B cells (enlarge when b cells are dividing and producing plasma cells)
- may form part of larger lymphoid organs (lymph nodes
- no T cells (only B)
32
lymph organs
- primary lymph organs are where B and T cells mature
- B cells mature and red bone marrow
- T cells mature in thymus (in lungs and heart)
33
secondary lymph organs
- where lymphocytes encounter their antigens and are activated
- lymph nodes
- spleen
- MALT (mucosa-associated lymphoid tissue) -> tonsils, appendix, peyer's patch (small intestine)
34
lymph nodes
- principle lymphoid organs of the body
- embedded in connective tissue, in clusters along lymphatic vessel
- most numerous and doing most of the work
- near the body surface in inguinal axillary, and cervical regions of the body
- follow the lymph system
35
functions of lymph nodes
- filter lymph- macrophages destroy microorganisms and debris
- immune system- lymphocytes are activated and mount and attack against antigens
36
structure of a lymph node
- bean shaped
- external fibrous capsule
- nodes are divided into compartments
- two histologically distinct regions
- cortex- germinal centers, follicles
- cortex contains follicles with germinal centers (heavy with dividing B cells)
- medulla- macrophages
- medullary sinuses contain macrophages!
- t cells circulate continuously among the blood, lymph nodes, and lymphatic stream
- surrounded by a dense fibrous capsule with an internal framework, or stroma, of reticular fibers that supports the lymphocyte
37
afferent lymphatic vessels
5
- more afferent vessels
- bringing in lymph fluid into the lymph node
38
efferent lymphatic vessels
2
| -lymph fluid exits the lymph nodes
39
circulation in the lymph nodes
- lymph
- enters via afferent lymphatic vessels
- travels through large subcapsular sinus and smaller sinuses
- exits the node at the hilum via efferent vessels
- fewer efferent vessels, causing flow of lymph to stagnate, allowing lymphocytes and macrophages time to carry out functions
- there are more afferent than efferent meaning more is being brought in than is leaving -> increases the amount of time the lymph spends in the lymph node -> allows more time for macrophages and break down and neutralize pathogens -> more efficient
40
enlarged lymph nodes
can be a sign of:
- fever
- fatigue
- sore throat
- swollen lymph glands
- infected lymph nodes- buboes
- obvious symptoms of bubonic plague, black death that killed much of europe during the middles ages
41
lymph nodes and cancer
- primary site- hoddgkins lymphoma or non-hodgkins lymphoma- swollen lymph nodes (not painful), fatigue and fever
- secondary site- cancer spreads via lymph-to-lymph nodes
- cancer spreads through the lymph system
- sentinel node- the 1st node from cancer site, tested for metastatic disease -> how to tell if the cancer is spreading
42
breast cancer and lymphedema
- one of the most common causes of lymphedema is removal of the breast (mastectomy) and underarm lymph tissue
- issue with the lymph system will cause swelling
- if you remove lymph nodes with a mastectomy the lymph will be drained less causing swelling
43
lymph tends to stall inside lymph nodes. this is due to ____
- small diameter spaces within the medulla
- the large volume of lymph entering the node
- fewer efferent lymphatic vessels than afferent lymphatic vessels*
- fewer afferent lymphatic vessels than efferent lymphatic vessels
44
what cells populate the germinal centers of lymphoid follicles
- t lymphocytes
- b lymphocytes*
- reticular cells
- macrophages
- dendritic cells
45
spleen
- largest lymphoid organ, size of your first
- served by splenic artery and vein, which enter an exit at the hilus
- contains lymphocytes, macrophages, and huge numbers of erythrocytes
46
spleen functions
- stores breakdown products of RBCs (iron) for later reuse
- stores blood platelets
- site of fetal erythrocytes production (normally ceases after birth)
- cleanses the blood of aged cells and debris
- site of lymphocyte proliferation and immune surveillance and response
47
structure of the spleen
- white pulp near central arteries- house lymphocytes- immunity
- red pulp in sinuses which houses macrophages- blood filtering
- splenic artery and vein enter via hilum- indented part of spleen
- surrounded by a fibrous capsule and contains both lymphocytes found in white pulp and macrophages found in red pulp.
48
splenomegaly
- enlargement of spleen due to accumulation of infectious microorganisms
- typically, from mononucleosis, malaria, and leukemia
49
thymus
-changes size with age
-increases in size and is most active during childhood
-stops growing during adolescence and then gradually atrophies
-differs from other lymphoid organs
-functions strictly in T lymphocyte maturation (not B cells)
-it does not directly fight antigens
-these thymocytes provide the environment in which T lymphocytes become immunocompetent (ability to start immune response)
-made up of thymic lobules containing an outer cortex and an inner
medulla.
-no B cells and, therefore, no follicles, it is not directly involved in fighting antigens
-stroma of the thymus consists of epithelial cells, not reticular fibers.
50
an advantage to having reticular connective tissue present in lymph nodes is that _________
- the loose organization of reticular connective tissue provides niches for macrophages and lymphocytes***
- lymph filters through the nodes and is exposed to lymphocytes and macrophages
- lymphocytes cycle to various areas of the body and back to lymph nodes
- all of the above take place
51
red pulp of the spleen is most concerned with ______, while white pulp is most concerned with ________
- immunity; new red blood cell formation
- filtering lymph; lymphocyte proliferation
- blood filtering; immunity***
- urine formation; blood filtering
52
MALT
- mucosa-associated lymphatic tissue, including (lymphoid tissue located in mucous membranes)
- peyer's patches (small intestine), tonsils, and the appendix (offshoot of large intestine)
- lymphoid nodules in the walls of the bronchi (respiratory tract)
- protects the digestive and respiratory system from foreign matter
53
aggregates of lymphoid follicles: peyers patches
- clusters of lymphoid follicles
| - in the wall of the distal portion of the small intestine
54
aggregates of lymphoid follicles: appendix
- tubular offshoot of LARGE intestine
- high concentration of lymphoid follicles
- vermiform appendix- worm shaped
- houses helpful bacteria for intestine
- lymph tissue accumulates after birth until 2nd/3rd decade
55
peyers patches and appendix
- both destroy bacteria, preventing them from breaching the intestinal wall
- generate memory lymphocytes
- cleanse digestive tract of bacteria
- if digestive material leaks it would cause bad sepsis
56
tonsils
- simplest lymphoid organ
- form a ring of lymphatic tissue around the pharynx
- contain follicles with germinal centers
- are not fully encapsulated
- epithelial tissue overlying tonsil masses invaginates, forming tonsillar crypts
- crypts trap and destroy bacteria and particulate matter that enter the pharynx in food and inhaled air
- palatine tonsils- at posterior end of the oral cavity
- lingual tonsils- grouped at the base of the tongue
- pharyngeal tonsil (adenoids)- in posterior wall of the nasopharynx
- tubal tonsils- surrounding the openings of the auditory tubes into the pharynx
57
tonsillitis
- bacterial vs viral
| - strep throat- contagious bacterial infection with sore throat, pus on tonsils, fever and enlarged lymph nodes
58
why is the lymphatic system one way
- takes all the lymph and takes it back to the heart to deposit back to circulatory system
- never takes fluid away from the heart
59
how do lymphatic capillaries differ from blood capillaries
- more permeable
- thinner
- one way valves
- when interstitial pressure increases lymph enters
60
areas of the body that are more densely clustered
- cervical
- axillary
- inguinal
