Week 4 Flashcards
(25 cards)
What is the cardiac cycle
All the mechanical and electrical events that occur during a single heartbeat
Diastolic phase
Relaxation phase
The chambers of the heart fill with blood
Systolic phase
Contraction phase
The ventricles contract and pump blood out of the aorta and pulmonary artery
Stroke volume
The volume of blood pumped from the ventricles per beat
Cardiac output
The amount of blood the heart pumps per minute
Blood vessels have 3 layers
Tunica intima
Tunica media
Tunica externa
Capillaries do not change size
Intrinsic (local) control of blood vessel size
Stretch, temperature and chemicals
Vasoconstriction
Vasodilation
Extrinsic control of blood vessel size
Autonomic nervous system and endocrine system
Vasoconstriction occurs in response to
Cold
Increased 02
Decreased C02
Decreased hydrogen
Vasodilation occurs in response to
Heat
Decreased 02
Increased C02
Increased hydrogen
What is muscular pump
Skeletal muscles squeeing blood in the veins to increase venous return
(Benefit of a warm down)
How much of the body’s mass is blood
8%
Blood content
55% plasma
45% cellular content
What are erythrocytes
(red blood cells) Contains a protein called haemoglobin, which carries oxygen from the lungs to all parts of the body
Where are erythrocytes made
Bone marrow
What is the life of an erythrocyte cell
4 months
What is erythropoietin
Transported through plasma where it is transported to the bone marrow to increase production of red blood cells
Where is erythropoietin produced/released
Kidneys
How many 02 molecules can 1 haemoglobin carry
4
How much oxygen in 1 litre of blood
200ml
197ml in haemoglobin
3ml in plasma
What is the oxygen dissociation curve
The relationship between haemoglobin saturation with oxygen and partial pressure of oxygen
What does an S-shaped curve represent
Changing affinity to oxygen
What are the 3 ways that carbon dioxide is transported throughout the body
Dissolved in solution
Bicarbonate ions
Bound to haemoglobin
