Wk7 Flashcards
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
Cancer screening
o Breast cancer screening: self-examination, mammograms
o Colorectal cancer: faecal occult blood testing, colonoscopy
o Cervical cytology: testing
what is leukemia
-A group of malignant disorders affecting the blood and blood forming tissues of the bone marrow, lymph system and spleen
what is lymphoma
Malignant tumour involving lymphocytes and the lymphatic system
hodgkin: single nodes,
non-hodgkin: multiple nodes
what is multiple myeloma
Malignant plasma calls (activated B cells) infiltrate bone marrow and destroy bone
what is neutropenia
- Decrease in neutrophils (innate immunity)
- Severe neutropenia= agranulocytosis
- Usual signs of infection may be absent as neutrophils are absent
nursing interventions for neutropenia
determine cause antibiotics hand washing positive pressure rooms visitor restrictions and screening IV line monitor closely for sepsis and infection
what is HIV/AIDS
- Human immunodeficiency virus
- Profound immunosuppression with opportunistic infections, malignancies, wasting and central nervous system degeneration
• CD4 helper T cells- regulate the immune system
• CD8 cytotoxic T cells- destroy body cells infected with virus, cancer
o HIV enters and uses the CD4 T helper cells to replicate
o Replication kills the CD4 T cell and releases further viruses
HIV 3 phases
primary infection phase
latency phase: Few signs or symptoms, lasts a long time
Overt AIDS phase
Tx for HIV
o Medication- anti-retroviral drugs- aims to reduce the amount of HIV in the body
o Vaccines and drugs to treat opportunistic infections
o Chemotherapy to treat non-Hodgkin’s lymphoma
what is anaemia and some nursing interventions
different types and causes, RBC level too low
o Easily fatigues- encourage patient to alternate activity periods with rest
o Limit visitors
o Plan ADLs, provide assistance when required
o Nutritional requirements
o education
what is polycythaemia
- Too many red blood cells
- Proliferative disease, or increased level or erythropoietin
- Hypertension, headache, inability to concentrate
- Increased risk of thromboembolism- increased blood viscosity
- Haemorrhage also occurs
normal WBC count
4-12
