Lab: Lymphatic and Immune System Flashcards
Organ system where immune cells are especially concentrated
Lymphatic system
NOT an organ system
but a collection of cells that defend against agents of disease
Immune system
What is the lymphatic system?
Consists of a network of veinlike vessels that penetrate nearly every tissue of the body and a collection of tissues and organs that produce immune cells
Functions of the lymphatic system
- Fluid recovery
- Immunity
- Lipid absorption
What does fluid recovery mean?
Collect/filter/return interstitial fluid
Capillaries absorb what percent of interstitial fluid?
85%
What percent of interstitial fluid is recovered by the lymphatic system?
15%
2-4L
In the lymphatic system, where does ISF pass through before re-entering the blood stream?
Lymph nodes and lymphatic tissue
Lacteals
Specialized lymphatic vessels in the small intestine
What vitamins do lacteals absorb?
A, D, E, K
- lipid soluble vitamins
Lymph
Clear, colorless fluid, that flows through lymphatic vessels
Lymphatic vessels
Transport lymph
Lymphatic organs
- Red bone marrow
- Thymus
- Lymph nodes
- Tonsils
- Spleen
What is different between lymph and blood plasma?
They’re very similar but lymph is low in protein
Does lymph flow use a pump?
No
Terminal capillaries
Microscopic lymphatic vessels formed by thin endothelial cells that loosely overlap each other
Collecting vessels
Lymphatic vessels that travel along veins and arteries that carry lymph to and from lymph nodes
What is the site of T and B cell activation?
Lymph nodes
Partially divide interior of node into compartments
Trabeculae with trabecular sinus
Outer region of the lymph node
Cortex with subscapsular sinus
Inner region of the lymph node
Medulla with medullary sinus
Where lymph enters the lymph node
Afferent lymphatic vessels
Where lymph exits the vessels
Efferent lymphatic vessels
Cisterna chyli
A sac where two lumbar trunks and intestinal trunk join
What are the two collecting ducts?
Right lymphatic duct
Thoracic duct
Has a capsule that separates the lymphatic tissue from neighboring tissue
Lymphatic organs
Primary lymphatic tissue definition
Sites where lymphocytes are produced and become mature or immunocompetent
Secondary lymphatic tissue definition
Site where immunocompetent lymphocytes migrate after they mature
Immunocompetent definition
The ability of T cells and B cells to distinguish foreign molecules from self
When do B lymphocytes and T lymphocytes become immunocompetent?
When they become capable of recognizing and responding to antigens
Where can red bone marrow be found?
proximal heads of the humerus and femur
Which type of cell reaches immunocompetence in red bone marrow?
B lymphocytes (B Cells)
Which type of cell reaches immunocompetence in the thymus?
T lymphocytes (T) cells
Aggregations of lymphatic nodules that guard against ingested and inhaled pathogens
tonsils
Tonsilitis
Acute inflammation of palatine tonsils usually treated with antibiotics
Tonsillectomy
Surgical removal of tonsils
In a fetus, where are blood cells produced?
Spleen
Largest lymphatic organ
Spleen
Functions of the spleen
- Monitors passing blood for antigens
- Reserve of monocytes
- Eliminates erythrocytes
- Reservoir of thrombocytes
Aggregations of lymphocytes in organs and connective tissues
Lymphatic tissues
Prevents invading pathogens from infiltrating the mucous membranes of the body
Mucose-associated lymphatic tissue
Where is mucosa-associated lymphatic tissue located?
Body passages open to exterior
- Respiratory tract
- Digestive tract
- Urinary tract
- Reproductive tract
Dense masses of lymphocytes and macrophages
Lymphatic nodules
Peyer’s patches
Aggregations of nodules in small intestine
What are thrombocytes fragments of?
Megakaryocytes
Do thrombocytes have a nucleus?
No
Where are erythrocytes produced?
Red bone marrow
Where do T cells mature?
Thymus
Types of T cells
- Memory T cells
- Helper T cells
- Cytotoxic T cells
Where do B cells mature?
Bone marrow
Types of B cells
- Memory B cells
- Plasma cells
Molecules capable of causing an immune response
Antigens
Proteins secreted by plasma cells to bind a specific antigen and mark it for elimination or destruction
Antibodies (immunoglobulins)
What types of lymphocytes respond more quickly to future infections by the same pathogen?
Memory T and memory B cells
Mobile antigen-presenting cells that function similarly to macrophages
Dendritic cells
Stationary antigen-presenting cells that are located in sinuses and bone marrow
Reticular cells
Cells that kill cancer cells and other infected host cells
Natural Killer cells
“Big eaters” that clear debris and present antigens to other cells
Monocytes –> Macrophages
What are the antigen-presenting cells?
- B cells
- Macrophages
- Dendritic cells
- Reticular cells
What do antigen-presenting cells do when they encounter an antigen?
- Internalize it
- Digest it into fragments
- Display relevant antigen fragments on membrane for T cells to inspect
What is the blood type if A antigens are present on an Erythrocyte?
Type A
What is the blood type if B antigens are present on an Erythrocyte?
Type B
What is the blood type if both A and B antigens are present on an Erythrocyte?
Type AB
What is the blood type if there are no antigens are present on an Erythrocyte?
Type O
Describe the antibodies erythrocytes have
The body makes antibodies against antigens not found on one’s own erythrocytes
Why would someone with type A blood, not produce antibodies for the A antigen?
Anti-A antibodies would react with antigen A, and tag the cell for destruction
When antibodies bind to antigens on the surface of erythrocytes causing clumping of erythrocytes
Agglutination
What is the purpose of agglutination?
Prompt an immune reaction
Why are agglutination and coagulation (clotting) different?
Agglutination is an immune response, coagulation is to prevent blood loss
Transfusion reaction
Occurs when incompatible blood is given during a transfusion
What would happen if someone with anti-A antibodies received type A blood?
- Agglutination follow by destruction of erythrocytes by hemolysis
- Free hemoglobin can block kidney tubules and causes renal failure
Hemolysis
bursting of blood cells
