Please enable JavaScript.
Coggle requires JavaScript to display documents.
Chapter 12 (12-4) (Regulation of Cardiac Cycle / Heart Rate (Autonomic…
Chapter 12 (12-4)
Regulation of Cardiac Cycle / Heart Rate
Autonomic Nervous system: Recall the cardiovascular center is located in mendulla of brainstorm
parasympathetic (normal) decreases; cardioinhibitor relfex center
Vagus nerve (cranial nerve # 10)
Release acetylcholine ACh (Lowers heart rate)
Sympathetic (stress) increases; cardioacceleratory reflex center
(Spinal Cord) Ne and E (Norepinephrine and epinephrine)
Increases heart rate
Atrial reflex (Bainbridge Refelx)
Chemicals
hormones
thyroxine increases force (thyroid)
glucagon increases force (pancreas)
calcium ions
hypercalcemia (extremely excitable)
hypocalcemia (very weak contractions)
potassium ions
hyperkalemia (weak and irregular contractions)
hypokalemia (heart rate is reduced)
Age (decreases)
Sex
females increased
males decreased
Temperature
lower, slow depolarization of SA node, lower heart rate, decreased contraction
Higher, increases heart rate, increases strength of contraction
Emotion
Disease
Cardiac output
Definition CO = the volume of blood pumped by each ventricle in one minuite
CO = heart rate (HR) x stroke volume (SV)
SV = volume of blood pumped out by a ventricle with each beat
Normal CO = 5 liters