1
Q
Functions of the Lymphatic System
A
- fluid recovery (2-4 L/day, prevents edema)
- immunity (lymph and blood monitored for pathogens and cancer cells)
- lipid absorption (via lacteals in small intestine)
2
Q
6 Types of Lymphatic Cells
A
T Lymphocytes - develop in thymus
B Lymphocytes - develop in red bone marrow, produce antibodies
Macrophages - develop from monocytes, phagocytotic
Natural Killer Cells (NK cells) - large lymphocytes that attack and lyse bacteria, foreign tissue, infected host cells
Dendritic Cells - branched cells in skin, antigen presenters
Reticular Cells - branched cells in stroma of lymphatic organs
3
Q
Lymphatic Fluid
- what is it?
- how is it produced?
A
AKA Lymph
- produced by filtration of plasma through capillaries
4
Q
Pathway of Lymph Flow
A
- towards the heart
- begins in dead-ended lymphatic capillaries where blood capillaries are (except: brain, teeth, bones, marrow)
5
Q
What is this structure?
Where is it found and where does it lead?
A
lymphatic capillaries
- smallest lymph vessel (larger than blood capillaries)
- permeable to lymph fluid and proteins via its valve-like overlapping endothelial cells
- dead-end at blood capillary beds and drain into lymph collecting vessels
- absent in cornea, bone marrow, CNS
6
Q
What lymphatic structures do lymphatic capillaries drain into?
What is their structure like?
A
lymphatic collecting vessels
- contain valves to molve lymph towards heart
- have the same three tunics as blood vessels, but thinner walls and lower pressure
- have lymph nodes along length to filer lymph
- lie along with veins in superficial tissues and arteries in deeper tissues
7
Q
The convergence of several lymphatic collecting vessels
A
lymphatic trunk
8
Q
the five major lymphatic trunks
A
- Lumbar Trunk
- Intestinal Trunk
- Bronchomediastinal Trunk
- Subclavian Trunk
- Jugular Trunk
9
Q
Paired lymphatic trunks branching off of the inferior end of the thoracic duct
A
Lumbar Trunks (left and right)
- carry lymph from lower limb, pelvic region and anterior abdominal wall
10
Q
Single lymphatic trunk branching off of inferior thoracic duct
A
Intestinal Trunk
- drains lymph from stomach, intestines and other digestive organs
11
Q
part C
A
bronchomediastinal trunks (left and right)
- carries lymph from thoracic viscera
- usually open into junction of internal jugular and subclavian veins
- sometimes join right lymphatic duct and thoracic duct
12
Q
part B
A
subclavian trunks (left and right)
- lymph from upper limbs, inferior neck and superior thoracic wall
- open either into junction of internal jugular and subclavian veins or into jugular trunk and thoracic duct
13
Q
part A
A
Jugular Trunks
- drains lymph from head and neck
- right side joins the venous angle (right internal jugular and subclavian veins)
- left side joins thoracic duct
14
Q
Where do the lymphatic trunks drain?
A
- into the lymphatic ducts
- two major ducts: thoracic duct and right lymphatic duct
15
Q
A
cisterna chyli
- dilated sac at inferior end of thoracic duct
- receives lymph from intestinal and lumbar trunks
- contains lots of chyle, fat-rich intestinal lacteal lymph
16
Q
A
Thoracic Duct
- joins junction of left subclavian and internal jugular veins (the venous angle)
- drains left side of face, most of left thorax and lower body
17
Q
top left question-marked structure:
A
right lymphatic duct
- joins right venous angle
- drains right side of head and upper body
- only present in 20% of people
18
Q
what is this collection of blue structures?
A
cervical lymph nodes
19
Q
what is this grouping of green and blue structures?
A
axillary lymph nodes
20
Q
what is this grouping of green structures?
A
inguinal lymph nodes
21
Q
Lymphoid Tissue
- what kind of tissue is it?
- what cells are found in it?
- where is it found?
A
- reticular connective tissue dominated by lymphocytes (T, B cells and macrophages)
- it is found primarily in two places:
- MALT (mucosa-associated lymphoid tissue) - mucous membranes of digestive, respiratory, urinary and reproductive tracts
- all lymphoid organs except thymus
22
Q
lymphatic capillaries that absord dietary fats within the villi of the small intestine
A
lacteal
23
Q
Lymphoid Nodules
- where are they found?
- how are they different from lymphoid organs?
- describe their structure
- name examples
A
AKA lymphoid follicles
- scattered clusters within lymphoid tissue
- they lack a fibrous capsule
- they are made of densely packed lymphocytes with a (usually lighter-staining) central zone of dividing cells (the germinal center)
Ex: tonsils and peyer’s patches
24
Q
Tonsils
- what are they?
- where are they?
- what do they do?
A
- large lymphatic nodules
- located in the pharynx and on the palate and tongue
- they trap bacteria and foreign pathogens entering the mouth and nose
25
B
**palatine tonsil**
- paired tonsils at the posterior inferior margin of oral cavity
26
A
**pharyngeal tonsils** (AKA **adenoids**)
- located in posterior wall of nasopharynx
27
C
**lingual tonsils**
- located along posterior third of tongue
- unpaired
28
boxed structure:
- what is it?
- where is it?
- what does it do?
**Peyer's patch**
- large isolated clusters of lymphatic nodules
- the ileal wall of the small intestine
- functions to destroy bacteria and generate memory lymphocytes for long term immunity
29
Lymphoid Organs
- what are they?
- how are they different from lymphoid nodules?
- how are they classified?
- give examples
- similar to lymphoid nodules in structure but are separated from tissues around them by a **fibrous capsule**
**Primary Lymphoid Organs** - produce lymphocytes
**Secondary Lymphoid Organs** - collect and destroy infectious organisms using lymphocytes
ex: **Lymph Nodes, Spleen, Thymus**
30
**Lymph Nodes**
- what are they?
- where are they?
- what do they do?
- what are large ones called?
- about 500 1-25 mm bean-shaped structures
- found along lymphatic collecting vessels
- macrophages within the node filter lymph of pathogens before it reaches the venous system
- large ones are called **lymph glands**
31
Lymph Node Structure Overview
- surrounded by **fibrous capsule**
- fibrous **trabeculae** extend inward and split the node into compartments
- divided into two regions: **cortex** and **medulla**
32
How does lymph flow through lymph nodes?
1. it flows in through **afferent lymphatic vessels,** then...
2. through **lymph sinuses** (subscapular, cortical and medullary), where macrophages cleanse it of pathogens, then...
3. it exits through **efferent lymphatic vessels** at the **hilum** of the node back into **collecting vessels**
33
round structure marked 4
**lymphatic nodule of lymph node**
- clusters of lymphocytes in cortex of lymph node
34
#3
**cortex** of lymph node
- outer region of lymph node
- consists of _cortical sinuses_ and _lymphatic nodules_
35
#4
**medulla** of cortex
- inner region of lymph node
- consists of _medullary sinuses_ and _medullary cords_
36
#3
**germinal center**
- areas in lymphatic nodules where b lymphocytes undergo mitotic division
37
#1
**medullary cords**
- CT fibers that support strands of lymphatic cells
38
#2
**medullary sinus**
- lymph percolates through these sinuses
39
the tiny dots that make up this image
**lymphocytes**
- white blood cells that attack specific types of antigens
40
what is the visible organ?
- describe its location
- what is its function?
- what are the two main types of tissue within it?
**Spleen** (largest lymphatic organ)
- located in upper left quadrant (left hypochondriac region)
- it stores blood and filters it to remove antigens and old blood cells
- also is site of hematopoiesis in fetus
- **red pulp -** engorged with RBCs
- **white pulp -** lymphocytes and macrophages collected like sleeves long central arteries
41
What is the organ at the superior end of the lungs, lying medial to them?
- what is its function?
- and why is it shown here on a child?
**Thymus**
- site of maturation of lymphocytes into "T" cells
- secretes **thymosin** and **thymopoietin** which stimulate immunocompetency of T cells
- it is most prominent in childhood when the immune system is developing, and is only 5% active by age 40
42
What is this structure?
What is it composed of and what is its function?
**Thymic** or **Hassall's Corpuscle**
- found in medulla of thymus lobules
- clusters of epithelial cells
- functions to develop **regulatory T cells** which prevent auto-immune responses
43
What is this structure and what kind of tissue does it contain?
**vermiform appendix**
- blind-ended puch extending from cecum
- contains **mucosa-associated lymphoid tissue (MALT)** which protect against pathogens entering through cecal mucosa
44
Z Old Anatomy
flashcards
Decks in class (21)
# Cards
-
Tissues63
-
Integumentary System47
-
Bones & Skeletal Tissues67
-
Joints62
-
Muscular System61
-
Selected Skeletal Muscles52
-
Nervous System56
-
The Brain100
-
spinal cord37
-
Peripheral Nervous System44
-
Autonomic Nervous System23
-
Special Senses111
-
Endocrine System76
-
Cardiovascular Part I: Blood34
-
Cardiovascular Part II: Heart66
-
Cardiovascular Part III: Blood Vessels97
-
Lymphatic System44
-
Respiratory System89
-
Digestive System137
-
Urinary System72
-
Reproductive System77
