Cardiovascular Flashcards
Primary function of the cardiovascular system (5)b
- Respiratory gas exchange
- Nutrient supply/waste removal
- Hormone signalling
- Fluid maintenance
- Body temperature regulation
Types of capillary
3
- Sinusoid (discontinuous) capillary
- Continuous capillary
- Fenestrated capillary
Locations of sinusoid capillary
3
- Spleen
- Liver
- Marrow
Locations of continuous capillary
Capillaries of most tissues
Location of fenestrated capillary
Glomerular capillaries
- Structure of large elastic arteries
- Function
- Example
- thick tunica media with lots of elastin
- Windkessel stretch to accommodate high blood pressure in systole
- Aorta, pulmonary artery, carotid
- Structure of muscular arteries
- Function
- Example
- Media composed of smooth muscle
- Distributing vessels
- Radial, femoral, coronary
- Structure of arterioles
2. function
- contain 1 - several layers of smooth muscle
2. Resistance vessels that act as the gateway for microcirculation
- structure of capillaries
2. function
- Endothelial cell layer resting on basement membrane. no smooth muscle
- Exchange vessels, diffusion occurs here
- structure of venules
2. function
- some smooth muscle present
2. collecting vessels. as blood leaves the capillaries
- structure of veins
- purpose
- examples
- thinner walls than arteries, less elastic tissue. valves present in limbs
- transporting deoxygenated blood back to the heart
- Vena cava, jugular vein
Valve between right atrium and right ventricle
Tricuspid valve
Valve between the left atrium and left ventricle
Mitral valve
Valve between left ventricle and aorta
Aortic semilunar valve
Valve between Right ventricle and pulmonary arteries
Pulmonary semilunar valve
Difference between cardiac and skeletal muscle
Presence of intercalated disks and gap junctions between the filaments in cardiac muscle
Calcium induced calcium release
- definition
- role of T tubule
- AP
- SR
- Cardiac muscle requires an influx of Ca2+ ions through voltage-gated Ca2+ channels for contraction
- T-tubule membranes act as voltage gated Ca2+ channels.
- During AP these open, allowing Ca2+ to enter heart cell
- triggering release of Ca2+ from SR for muscle contraction
Cardiac muscle -Excitation? - Organisation? - Action potential duration? - tetanus? Dependance on Ca2+ influx?
- Electronic spread from pacemaker region
- striated, branching
- long (350ms)
- No
- great
Skeletal muscle -Excitation? - Organisation? - Action potential duration? - tetanus? Dependance on Ca2+ influx?
- neuromuscular junction
- striated, isolated motor unit cells
- brief (5ms)
- yes
- little
Smooth muscle -Excitation? - Organisation? - Action potential duration? - tetanus? Dependance on Ca2+ influx?
- Neurohumoral/electrical
- non-striated, electrically coupled
- only exceptionally
- slow tension development
- great
From where does autonomic regulation of heart rate originate in the brain?
The medulla oblongata
- How many days for the primordial heart to develop in a foetus?
- What shape does it form?
- What happens at 4-5 weeks
- Primordial heart is developed by 23 days
- Forms a tube which forms different bulbs, blood vessels begin to form and join
- At 4-5 weeks the heart tube begins to fold in on itself, forming primitive L/R atria and ventricles
Comparison of foetal and adult circulation (3)
- Reliance?
- Supportive organs?
- UV?
- The foetus is completely reliant on maternal circulation for oxygen and nutrients
- These come from the placenta and are delivered by the umbilical cord and umbilical vein
- Umbilical vein carries oxygenated blood into the liver and the inf. Vena Cava, via the ductus venosus, of the foetus
Foramen ovale?
- A junction between atria in the foetal heart