Circulatory system Flashcards
MAP(mean arterial pressure)
cardiac output x total peripheral resistance
Veins serve as a _____ ______ and ____ ______ to the heart.
pressure resevioirs
return blood
Arterioles are major ______ vessels
resistance
What are the components of a a circulatory system?
- FLUID that carries that carries transported molecules and cells
- a PUMP to move the fluids
- VESSELS to carry fluid between the pump and the body fluid
Open circulatory system
hemolymph moves through vessels that open into extracellular space.
closed systems
-Blood is pumped from a heart through vessels that
return blood to the heart
-Capillaries are the primary structure distinguishing a closed from an open system
Blood + interstitial fluid=
Haemolymph
What are disadvantages of an open system?
Limited ability to alter the velocity or distribution of blood flow. Also low rate of oxygen transfer
What animal has parallel circulation?
amphibians
What animal has single circulation?
Fish
What animal has double circulation?
mammals, birds and crocodiles
What is an important characteristic of Double circulation?
Complete separation of pulmonary and systemic blood
What are the advantages of double circulation
Systemic circulation can operate at a high arterial pressure so that flow can be selective to organs and tissues
• Pulmonary circulation is a low pressure, low resistance circuit so that fluids wont go into your lungs
What are the advantages of parallel circulation?
Cardiac output (ml/min) can be different in
systemic and pulmocutaneous circulations
• Adapted to periodic ventilation - blood diverted to lung while breathing and away from lung during apnea.
What is the disadvantage of parallel circulation?
Single ventricle produces relatively low blood pressure
Arteries
carry blood away from the heart. serve as pressure reservoir
Arterioles
(small branches of arteries) deliver blood to
capillaries
Capillaries
exchange material with interstitial fluid
venules
collect blood from capillaries
Veins
return blood to the heart
lymphatic system
Remove viruses, bacteria, damaged cells and cellular debris from lymph and blood stream.
Defends the body against infection and cancer
What are the tissues and organs of the lymphatic system?
Lymph nodes, spleen, thymus, tonsils
what is the heart beat produced of?
by a cycle of contraction and relaxation of the atria and ventricles
Membrane potential of pacemaker cells slowly
depolarizes due to:
- Increased inward Na+ current
- Decreased outward K+ current
- Increased inward Ca2+ current
blood is pumped into what two separate circuits?
-Pulmonary circuit (right heart)
– Systemic circuit (left heart)
systolic pressure
Contraction of ventricles pushes blood into
arteries at peak pressure
diastolic pressure
Between contractions, blood pressure in arteries
falls to a minimum pressure
Thick, muscular myocardium is sandwiched between ______ and _______
endocardium and epicardium
P wave
Atrial depolarization
QRS Complex
ventricle depolarization
T wave
Ventricle repolarization
on a ECG where are periods of no current flow?
PR segment, ST segment, TR interval
Arteries’ elasticity enables them to _______ during
ventricular systole
expand
what is the driving force for continued flow of blood during diastole
Elastic recoil