Spleen Flashcards
What system is the spleen part of?
Reticuloendothelial system
What process do all cells and tissue exhibit?
Phagocytosis
Where does hematopoiesis occur within a fetus?
Spleen, liver and bone marrow
Where does hematopoiesis occur postnatally?
Bone marrow
What is included within the RE system?
Brain, blood, spleen, liver, thymus, bone marrow and lymph nodes
What is blood composed of?
RBCs, WBCs, platelets (thrombocytes) and plasma
How many leukocytes are there per cubic mm?
5,000 - 10,000
What is leukocytosis?
Rapid division of cells in the presence of infection
What is leukopenia?
Decrease amount of leukocytes
When is there a decrease of leukocytes?
Drug and chemical toxicity and viral infections
What are the 5 different types of leukocytes?
- Neurophil
- Eosinophils
- Monocytes
- Lymphocytes
What WBCs perform phagocytosis?
Neutrophils, eosinophils and monocytes
What WBCs are non-phagocytic cells?
Lymphocytes
Describe the 3 processes of immune response
- Body recognizes the chemical composition of substances and decides if its alien or not
- If the body is alien it reacts and produces antibodies and anti-toxins
- Body produces memory cells- antibodies and antigens are produce specific antigen
What is a humoral immune response?
Antibodies (gamma globulins) are liberated into the plasma by committed lymphocytes
What is a cell mediated immune response?
Lymphocyte produces antitoxins that are retained within lymphocyte cell
Lymphocyte attaches to antigen and secretes antitoxin
Both antigen and lymphocyte die and are absorbed
What is the largest unit of the RE system?
Spleen
When does the spleen develop?
5th week gestation
What type of cells does the spleen arise from?
Mesodermal cells
When does the spleen start performing hematopoietic functions?
Starting at 11 weeks gestation
This function ends shortly after birth
When does the spleen assume adult function?
5th or 6th month gestation
What cavity is the spleen located in?
Retroperitoneal
Is the hilum covered in peritoneum?
No
Is the spleen encapsulated?
Yes
What quadrant does the spleen lye in?
LUQ
What rib does the long axis of the spleen lye by?
10th rib
What ligaments anchor the spleen in place? (3)
- Gastrosplenic
- Splenorenal
- Phrenocolic
What structure is superior/lateral/posterior to the spleen?
Diaphragm
What structures are medial to the spleen? (4)
- Stomach
- Tail of pancreas
- Splenic flexure of colon
- Left kidney
What structure is anterior to the spleen?
Stomach
What is the average adult size of the spleen?
L: 11cm but not > 12cm
W: 7-8cm
H: 3-4cm
What is the normal size of the spleen?
Up to 12cm