Lecture 3

Question 1

animal models: what factor important for autonomic response?

how?

Answer 1

animal models: predator imminence

no imminent threat: cardiac deceleration

> orienting reflex + freezing

immiment threat: cardiac acceleration

> defense reflex + fight or flight

Question 2

what is the PEP

Answer 2

PEP: pre ejection period

> start contraction left ventricle until opening aortic valve

Question 3

what is LVET

Answer 3

LVET: left ventricular ejection time

> opening aortic valve until closing aortic valve

Question 4

how does the SNS influence PEP?

Answer 4

sympathetic nervous system activity increases cardiac contractility

> left ventricle contracts stronger/faster

> shorter PEP

Question 5

what is HPV?

what does it reflect?

how?

Answer 5

HRV: heart period variability

HPV reflects parasympathetic nervous system activity

> when PNS activity increases, vagal gating effects become larger > HPV increases

Question 6

how can you measure PNS activity?

Answer 6

PNS activity is reflected in respisatory sinus arrhytmia

RSA = longest heart period during exhalation - shortest heart period during inhalation