Transcript File

Heartbeat regulation
Heartbeat - SA Node
Sinoatrial node (SA)
= Pacemaker
Small group of
cardiac muscle cells
Starts the wave of
heart muscle
contraction
“Sets the pace”
Heartbeat - AV Node
Atrioventricular
node (AV)
Bundle of fibers
Picks up impulses
from the SA node
and transmits to
network of fibers in
the ventricles
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Regulation of the
Heartbeat
Disorders of the
Circulatory System
Disorders of the Circulatory
System - Atherosclerosis
• Fatty deposits in
walls of arteries
• Obstruct blood flow
and raise blood
pressure
• Increase risk of
blood clots
Disorders of the Circulatory
System - Heart Attack
• Caused by blocked
arteries
• Blood cannot get to the
heart muscle
• Heart muscle begins to
die due to lack of O2
Disorders of the Circulatory
System - Stroke
• Blood clot breaks free
and blocks a vessel
leading to the brain
• Brain cells starved of
O2 and nutrients
• May cause paralysis,
loss of ability to speak or
death
Disorders of the Circulatory
System - High Blood Pressure
• Blood pressure is the
measure of force
exerted by the blood on
the wall of the arteries
• Too much pressure
can cause health
problems such as heart
disease
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Heartbeat
Heartbeat depends
on body’s need for
oxygen-rich blood
Increase heart beat:
Sympathetic
nervous system
Decrease heart
beat:
Parasympathetic
nervous system