Ch 2- Flashcards
Atherosclerosis
Build up of fatty plaque on coronary blood vessels in the heart, decreasing flow of blood through vessels resulting in downstream symptoms
Primary funciton of circulatory system
bringing O2 and
nutrients to organs and transporting CO2
and other waste products for removal
Leading cause of death in canada
Heart Disease
Angina
Chest pain
Sometimes associated with actual pathology, sometimes not
Coronary artery disease
CAD
When major blood vessels that supply the heart struggle to send enough blood O2 and nutrients to theheart muscle
Myocardij
Middle and thickett layer of heat wall
Responsible for pumping action
Age related changes to the myocardium
Decreasing cardiac contractility
* More time is required for diastolic
filling and systolic emptying
* Less responsive to sympathetic
nervous system (fight or flight)
Electrophysiology decline of myocardium
Less pacemaker cells
* Irregularity in the shape of
pacemaker cells
* Increased deposits of fat,
collagen and elastic fibers around
SA node
Vasculature
Network of blood vessels
Age related physical changes to vasculature
Diameter of lumen of aorta
increases to compensate for
arterial stiffening
Veins, like arteries, become
thicker, more dilated, and
less elastic
* Increased vascular resistance
causes a slight increase in
the systolic BP
Other changes as a result of vasculature changes
Increased peripheral resistance affecting flow to vital organs
Due to peripheral resistance, left ventricle hypertrophy
Valves of large leg veins become less efficient at returning blood to the heart
Baroreflex mechanism
Receptors in aortic arch and caroitc artery
Physiologic process regulating BP
Baroreflex Mechanism-Age related changes
- Decreased compensatory responses in both hyper- and
hypotensive stimuli (ie heart rate does not increase or
decrease as efficiently in older adults as in younger
adults) - Baroreceptors in the large arteries (carotid and aorta)
less effective in controlling BP, especially during
postural changes
Consequences of Age-related changes
Decreased adaptive response to exercise
* Slightly lower hear rate
* Increased susceptibility to hyper AND hypotension
* Increased susceptibility to arrhythmias (ie. atrial fibrillation)
* Decreased cerebral blood flow
Ventricular fibrillation
An arrhythmia when lower heart chambers controcat in very rapid uncoordinated manner mean heart doesn’t pump blood to rest of body