Cardiovascular system Flashcards
Blood pressure equation
PB = CO x Systemic Vascular Resistance
What affects SVR and therefore BP
Blood viscosity (blood thickness) Vasodilation or Vasoconstriction Blood vessel length
Blood Viscosity
Increase in BV = increase SVR = BP decreases
Blood vessel length
Increase/longer the BVL= Increase SVR= Decrease BP
Blood vessel diameter
Vasoconstriction= increase SVR= Decrease BP
Vasodilation = Decrease SVR= Increase BP
Cardiac output equation
CO= HR x SV
What affects CO
Stroke volume
- preload (heart muscle stretch before contraction)
[increased preload= increased SV)
- Afterload (resistance that must be overcome before blood is ejected from ventricle)
[increase afterload= decrease SV]
-contractility
[increase contractility = increase SV]
Heart sound 1 [lub]
Closure of the two atrioventricular valves- bicuspid and tricuspid valves
[ bottom ]
Layers of the Heart wall
outer to inner
epicardium
myocardium
endocardium
heart sound 2 (Dub)
Closure of the two semilunar valves – Pulmonary semilunar and Aortic semilunar valve.
Pulmonary semilunar valve
Between the right ventricle and pulmonary trunk.
[Receives deoxygenated blood and pumps to the lungs]
Aortic semilunar valve
Between the left ventricle and Aorta.
[recieves oxygenated blood and pumps to the body]
Atrioventricular valves
Right AV valve = deoxygenated blood from Right atrium and to right ventricle.
Left AV valve = Oxygenated blood from the Left atrium to the left ventricle.
conduction system
Heart activity and contraction is initiated by the conduction system [initiated an action potential at the SA node]
ordered structures action potential travels
- SA node
- AV node
- AV bundle
- Bundle branches
- Purkinje fibers
Electrical events at the SA node
Cardiac action potential
- Depolarization
- Plateau
- Depolarisation
depolarization
- voltage-gated NA+ (sodium) channels open
- membrane potential goes -90mV to 30
- Sodium rushes into the Nodal cell
platea
- voltage-gated k+ ( potassium) opens and potassium moves out cardiac muscle cells.
- slow voltage-gated Ca+ (calcium) opens and calcium enters cell.
- this balances the electrical charge and depolarisation is maintained.
Repolarization
- Voltage-gated calcium channel close
- Voltage-gated K= (potassium) channels remain open and K moves out.
- polarity drops from 10 to -90mV
lymphatic system function and structure
lymph vessels, lymphatic tissue, and organs that support the cardiovascular and immune system by absorbing interstitial fluid that is not reabsorbed by venous end of capillaries and returning it to venous circulation.
Primary lymphatic structure
formation and maturation of lymphocytes
- Red Bone Marrow [produces lymphocytes]
- Thymus [site of t-lymphocyte maturation]
secondary Lymphatic structures
House lymphocytes and other immune cells as well as the site to initiate the immune response.
- lymph nodes [filter lymph (fluid) and house lymphocyte cells]
- spleen
- tonsils
lymphatic nodules
secondary Lymphatic structures
House lymphocytes and other immune cells as well as the site to initiate the immune response.
- lymph nodes [filter lymph (fluid) and house lymphocyte cells]
- spleen
- tonsils [protect against ingested substance]
lymphatic nodules and MALT
spleen
- filters blood by removing bacteria and foreign substances, removing old erythrocytes and platelets.
- storage site for erythrocytes and platelets.
Net filtration pressure
Difference between hydrostatic pressure and net colloid osmotic pressure.
[positive at the arterial end of the capillary
= filtration out of capillary]
[negative at venous end of the capillary
= reabsorbtion]
the lining of the heart
Pericardium
Outer = Fibrous pericardium
Middle= Parietal layer of serous pericardium
Inner = Visceral layer of SP (epicardium)
