Wk7 Flashcards
(36 cards)
components/make up of blood
o Plasma: 55% of the blood volume, watery liquid that contains dissolved substances
o Formed elements: 45% of blood volume, cells and cell fragments
bloods main function
o The transportation of oxygen, essential nutrients, hormones, enzymes and chemical to all cells
o Removal of carbon dioxide and other waste products from the cells
o The maintenance of homeostasis
o Protecting the body from invading micro=organisms and antigens i.e. immunity
o Regulation of electrolyte, water and acid-base balance
o Regulating body temperature
cellular components in blood
There are three main types of cell in blood
o Leukocytes: monocytes, neutrophils, eosinophils, lymphocytes
o Erythrocytes: red blood cells
o Thrombocytes: platelets
The percentage of RBCs in the blood is referred to as the haematocrit
manufacture of blood cells
blood cells are manufactured in the red bone marrow of mature bones
- All blood cells are derived from the same pluripotent stem cell
- Develop into different types of stem cell
o Myeloid stem cells: RBC, platelets, monocytes, neutrophils, eosinophils
o Lymphoid stem cells: T and B lymphocytes
hormones that regulate production include
o Erythropoietin (kidneys)
o Thrombopoietin (liver)
o Cytokines
what are RBC
erythrocytes live 120 days replace 2 million cells every second bind to O2 do not have the ability to repair, grow or reproduce
what are WBC
provide protection against micro-organisms and parasites
phagocytosis, cell-mediated and antibody-mediated immune response
cell mediated immunity
- Linked to the role of T-cell
- When in contact with an antigen the T-cell forms many other clones of itself
o Helper T-cells: mediate response, release chemical messengers, attracted phagocytes
o Killer T-cells: do the damage, cytolysis
o Memory T-cells: remain for swifter attack next time antigen present - Phagocytes: neutrophils and macrophages that ingest foreign cells and antigens
antibody mediated immunity
exposure of B-lymphocytes to an antigen
- When in contact with an antigen, the B cells are stimulated to grow and divide
- Form plasma cells and memory B cells
- Plasma cells produce the antibodies at an astounding rate
what are thrombocytes function
- Platelets are essential for haemostasis
- form blood clots
- Clump together to form a platelet plug and stimulate clotting cascade
- Come from megakaryocytes that develop from myeloid stem cells
- 5-9 days
what is thrombophilia
- abnormality of blood coagulation
- Increases the risk of thrombosis
what is thrombosis
- Formation of a blood clot inside a blood vessel
- Obstructing the flow of blood through the circulatory system
- Venous thrombosis leads to congestion of the affected part of the body
- Arterial thrombosis affects the blood supply and leads to damage of the tissue supplied by that artery
what is a thromboembolism
- piece of either an arterial or venous thrombus can break off as an embolus
- travel through the circulation and lodge somewhere else as an embolism
- DVT
- VTE can lodge in lung as PE
- arterial thromboembolism can lodge in heart as MI, brain as stroke
Risk factors of thrombosis
Virchows triad: factors contribute to thrombosis
Hypercoagulability: surgery, trauma, pregnancy, inflammation
hemodynamic changes: immobility, low heart rate, AF
endothelial injury/dysfunction: atherosclerosis, cellulitis
provoked and unprovoked DVT or PE
provoked: major risk factor, trauma
unprovoked: no identifiable risk factors, cancer
what is factor 5 leiden
variant (mutated form) of human factor 5
o Causes and increase in blood clotting
- Anticoagulant protein secreted normally inhibits the pro-clotting activity of factor 5
- Not able to bind normally to factor 5 leading to a hypercoagulable state
what is thrombocytopenia
- Decrease in the number of circulating platelets
usual cause is disease of bone marrow
Tx: Corticosteroids slow the spleen’s destruction of old platelets, increasing their life span; platelet transfusions, Prevent/control bleeding
what are some clotting factor deficiencies
- Vitamin K deficiency- needed for liver to produce active clotting facots
- Haemophilia- primarily hereditary; reduction in clotting: factor 8 or 9
what is neoplasm
- Neoplasm is an abnormal mass of tissue as a result of neoplasia, the abnormal proliferation of cells
- usually causes a lump or tumour
- They can be benign, malignant or premalignant
what is a benign neoplasm
- Lacks all three of the malignant properties of cancer
i.e. They do not
o Grow in an unlimited, aggressive manner
o Invade surrounding tissue
o Spread to non-adjacent tissues
What is malignant
o Uncontrolled growth
o Invasion- intrusion and destruction of adjacent tissues
o Metastasis- spread to other locations in the body via lymph or blood
what is an oncogene
Mutant genes that in their non-mutant state direct protein synthesis and cellular growth
what is a tumour suppressor gene
Encoded proteins that in their normal state negatively regulate proliferation
describe cancer staging
Assigned a number from 1-4 to a cancer
• 1: isolated cancer
• 4: cancer which has spread to multiple sites
Abbreviations of cancer staging
o T: Primary tumour, the number equals size of tumour and its local extent. The number can vary according to site o T0: Breast free of tumour o T1: Lesion less than 2cm in size o T2: Lesion 2-5cm in size o T3: Skin and/or chest wall involved by invasion o N: Lymph node involvement, a higher numer means more nodes are involved o N0: No axillary nodes are involved o N1: Mobile nodes are involved o N2: Fixed nodes involved o M: Extend of distant metastases o M0: No metastases o M1: Demonstrable metastases o M2: Suspected metastases
