The Cardiovascular System Flashcards
Function of Blood
Transport- O2, C02, nutrients, hormones
Regulation- pH, temperature
Protection- clotting to prevent blood loss, WBC production to prevent infections
Components of Blood
- Blood Plasma (55%)
- Formed Elements (45%)
(1%- buffy coat)
Whole Blood Components
RBC, WBC, Lymphocytes, Platelets
RBC function
Biconcave disc that has haemoglobin. Function is to transport oxygen
WBC function
Combat inflammation and infections
Basophil: inflammation in allergic reaction and liberate histamine, heparin, serotonin
Eosinophil-> inflammation in allergic reaction and effective against parasitic worms
Neutrophil-> first response to bacterial invasion
Lymphocytes function
B-cells: develop into plasma cells and produce antibodies
T-cells: Attack viruses, fungi and cancerous cells
Neutral Killer cells: Attack a variety of infecious microbes and tumour cells
Platlets function
Disc-shaped cell fragments without nuclei that take part in haemostasis
Haemostasis
Sequence of responses that stop bleeding when blood vessels are injured
Mechanisms can reduce loss of blood from blood vessels
- Vascular Spasm
- Platelet Plug Formation
- Blood clotting (coagulation)
- Formation of prothrombinase
- Conversion of prothrombin to throbin
- Throbin coverts soluable fibrogen into unsoluble fibrin
Hormonal Control
Renin–angiotensin–aldosterone (RAA) system: kidneys secrete the enzyme renin to increase BP.
Epinephrine and norepinephrine: sympathetic stimulation increases cardiac output.
Antidiuretic hormone (ADH): hypothalamus and post. pituitary causes vasoconstriction and increased BP.
Atrial natriuretic peptide (ANP): atria of heart causes vasodilation and lowers BP.
The Heart Wall
Epicardium (outer layer)
Myocardium (middle layer)
endocardium (inner layer)
Cardiac Conduction- ECG
P-wave= Contraction of atria
QRS= Contraction of ventricle
T-wave= Relaxation of ventricle
