Cardio Flashcards
Primary Cardiovascular Disturbances
Congenital = Valve defects, wall of heart defects, major blood vessel defects, clotting disorders Acquired = Haemorrhage, clotting, primary cardiac disease, parasitic infection
Secondary Cardiovascular Disturbances
Vomiting, diarrhoea = cause heart arrhythmias, heart failure
Septic shock = blood poisoning
Anaesthetic overdose = depress central nervous system and heart function
Describe the components of the cardiovascular system & their primary functions
Heart, Blood Vessels, Blood= pumps and supplies blood to body, supplies oxygen, nutrients, removes waste
Blood functions-
Transport of gases, nutrients, waste
Regulation of temperature and pH (homeostasis)
Protection – clotting and immune functions
Describe in detail the basic composition of blood
Plasma = matrix
Erythrocytes - RBC
leukocytes - WBC
thrombocytes - platelets
Erythrocytes properties
Properties – Biconcave, flexible, live for 2-6 months, lack nuclei and organelles ** reptiles contain nuclei
Plasma function
Plasma = contains proteins and electrolytes
Proteins – globulin (immune function), albumin (fluid balance of blood), fibrinogen (clotting, inflammation)
Electrolytes – Na+, Cl-
Name the erythrocyte in cattle and why it is different to other mammals
Anisocytosis (variation in RBC size) - cattle
Name the type of RBC that varies in shape, and in what animal
Poikilocytosis (variation in RBC shape) – goats, cattle
Describe Erythropoiesis
production of erythrocytes (no nucleus thus cannot undergo mitosis) Performed by stem cells
Rate is determined by erythropoietin in the kidneys = under endocrine control
Explain blood component formation
haematopoiesis is where Erythrocytes and leucocytes develop by mitosis and differentiation from stem cells within the bone marrow
Describe clinical haematological tests
Collect sample – use anticoagulant (EDTA) to stop clotting
Haematocrit (Hct) – Packed cell volume (PCV), erythrocyte composition
% affects viscosity and fluidity of blood
What is the type of haemoglobin measurement
Mean Corpuscular (cell) Haemoglobin (MCH) = Mean Corpuscular (cell) Haemoglobin Concentration (MCHC) = [Hb]/Hct
What does high protein in blood indicate
- Haemoconcentration eg. dehydration
– Increased globulin production eg. inflammation or infection
What can low protein in blood indicate
– Loss of protein via the kidneys (protein losing nephropathy)
– Loss of protein via the gastrointestinal system (protein losing enteropathy) – Loss of lymph
– Chronic or severe blood loss
– Lack of plasma protein production by liver
How is bloody typed
Blood cross match testing - detect presence of haemagglutinating & haemolysing antibodies in serum of donor & recipient animals
What is major and minor cross matching
Major cross-match = donor RBCs + recipient plasma
Minor cross-match = donor plasma + recipient RBCs
What role do white blood cells (leucocytes) play
Leukocytes are larger than red blood cells, have an immune function and contain a nucleus, organelles and cytoplasmic vesicles
Name the two types of WBC
arangulocytes
granulocytes
name and describe two types of aragulocytes
LYMPHOCYTE – Large, spherical, slightly indented nucleus– dark purple stain
- Specific immune response function (B and T lymphocytes)
MONOCYTE – Variable shape, blue/grey staining
- Phagocytic function, contain lysosomes
name and describe the three types of granulocytes
EOSINOPHIL – large, uniform, bilobed nucleus, red/orange staining
- Kills parasitic worms, modulate inflammation, allergic reactions
BASOPHIL – U/S shaped nucleus, blue/purple staining (rare in cats, dogs, horses, ruminants) - Immediate hypersensitivity reactions (contain histamine and heparin)
NEUTROPHIL – predominant granulocyte, irregular, knobbly nucleus, lilac staining
- Initiate immune system, 1st line of defence against bacteria and some fungi
Explain the role of platelets in primary haemostasis.
PLATELETS- also called thrombocytes, non-nucleated
ROLE – homeostasis and clotting
ACHIEVE HOMEOSTASIS BY – minimise or prevent blood loss
1) contraction of injured blood vessel
2) Formation of platelet plug
3) Coagulation of blood
Describe the mechanisms involved in primary haemostasis
PRIMARY –
VASCULAR PHASE- Reflex vasoconstriction temporarily restricts blood flow
Direct mechanical input on smooth muscle of vessel wall, release of vasoactive substances
30 min
PLATELET PHASE – damage to endothelium stimulates platelet adhesion and plug formation
Describe the mechanisms involved in secondary haemostasis.
SECONDARY – COAGULATION
Occurs at the same time as primary haemostasis
Causes consolidation of temporary platelet plug – blood clot formation
‘Coagulation cascade’ of enzymatic processes – intrinsic, extrinsic, common pathways Coagulation – conversion of soluble plasma protein fibrinogen into insoluble threads of fibrin, this traps RBCs and form gelatinous clot
describe the contents of the mediastinum
MEDIASTINUM – space in the medial thorax region, extending from thoracis inlet to the diaphragm
consists of
- cranial vana cava
- lymph nodes
- thymus (immune system)
- phrenic nerve (controls diaphragm)
- vagus nerve (internal organ functions)
- oseophagus
- aorta
- heart