NRSG 126 - Week 7

Question 1

The ageing Heart

Answer 1

• Thickening blood vessel walls
• Narrowing lumen
• Less elastic vessels
• All these changes together make the heart have to work harder to be more efficient, impact cardiopulmonary tolerance, increase risks associated with changes as will be discussed today.

Question 2

what happens to Pulmonary vascular tension, Risk of orthostatic hypotension, SBP (systolic BP)

Answer 2

increased

Question 3

what happens to Peripheral circulation, Cardiac output, Heart muscle fibers, Baroreceptor sensitivity, Venous valve efficiency, Heart valve efficiency

Answer 3

decreased

Question 4

what happens to CO

Answer 4

o Decreased CO- many resources talk about this being more of an issue not at rest but activity tolerance- affecting max CO

Question 5

what happens to valves and fibers

Answer 5

valves - calcification and less elastic
Decreased fibers- decreased capacity- esp left ventricle

Question 6

what do Baroreceptors do

Answer 6

control BP- increases risk of ortho hypotension.
 decreased baroreceptor sensitivity- may also lead to why more older adults have orthostatic hypotension. Drop with positional changes (20mm Hg SBP and 10mm Hg Diastolic)- defined in VS week and more in immobility readings.

Question 7

Cardiac Structure and Function

Answer 7

• approximately the size of your fist
• left side of your chest
• Base (top)
• Apex (bottom)- Apex 5th ICS (intercostal space) ~7-9cm from midsternal line
• Apex touches the chest wall- this is why it is the PMI or Point of Maximal impulse. In lab you may discuss auscultating at the Apex or Erbs point. Either is fine just to check for regular or irregular HR,
  The front of the heart is mostly the RV (right ventricle).

Question 8

veins

Answer 8

low pressure and use valves and some use muscles. Deoxygenated except for pulmonary.

Question 9

arteries

Answer 9

high pressure- oxygenated except for pulmonary. Aorta is the largest in the body!

Question 10

What is an aneurysm (also causes and repair)

Answer 10

• A complication with HTN discussed in the video is a term Aneurysm. This is a bulge that can burst (called dissection).
  o Causes? Unhealthy behaviours- HTN, smoking, atherosclerosis (fats, cholesterol and other) and high cholesterol.
  o Repair- Dacron graft (textile polyester synthetic graft)

Question 11

what and where is the coronary sinus

Answer 11

• Coronary sinus is in the right atrium and is where de-oxygenated blood enters the rt. Atrium from the myocardium.

Question 12

what and where are the coronary arteries

Answer 12

• Coronary arteries, in the lt. aorta, feed the myocardium during diastole.
  In the human heart, two coronary arteries arise from the aorta just beyond the semilunar valves; during diastole, the increased aortic pressure above the valves forces blood into the coronary arteries and thence into the musculature of the heart.
• Left Ventricle is the largest and strongest. Pumping into systemic circulation!

Question 13

cardiac conduction process

Answer 13

• ANS influence – pacemaker (electrical) – form an impulse – passes along conduction system

Question 14

what controls heart beats

Answer 14

• Heart beats are controlled by the pacer (SA node) but can be impacted by the medulla oblongata (ANS control).
  o SNS increase Norepinephrine and Adrenaline (adrenals)
  o PNS decrease via vagus nerve (ACH)
  o Senses changes to BP and CO2 to compensate.
• SA intrinsic rate of 60-100!