Unit 1 Day 4

Question 1

Heart Failure

Answer 1

-inability of heart to pump blood forward at sufficient rate to meet demands of body, or ability only to do so if cardiac filling pressures are abnormally high -dec. in cardiac output is hallmark -backward buildup of pressure is almost always present as well (congestion)

Question 2

Systolic Heart Failure

Answer 2

• problem with squeeze (dec. contraction, dec. inotropy)
• hallmark is dec. ejection fraction
• ventricular enlargement
• primary cause myocardial infarction

Question 3

Answer 3

Systolic Heart Failure

• loss of inotropy
• dec. SV
• lower generated systolic blood pressure
• dec. ejection fraction
• ventricular enlargement

Question 4

Dyastolic Heart Failure

Answer 4

• impaired filling
• dec. lusitropy/relaxation
• hallmark is normal ejection fraction and ventricular wall thickening

Question 5

Answer 5

Dyastolic Heart Failure

• inc. stiffness requires inc. pressure to achieve same LV filling volume
• dec. SV
• dec. lusitropy
• normal ejection fraction
• ventricular wall thickening
• causes: high afterload/pressure overload, myocardial thickening/fibrosis, external compression

Question 6

Compensatory Responses to Dec. Cardiac Output Seen in Heart Failure

Answer 6

• dec. cardiac output leads to neurohormonal activation of adrenergic and renin-angiotensin-asdosterone systems (RAAAS), which leads to inc. Na retention and vasoconstriction
• Frank-Starling inc. preload- SV preserved by inc. end-doastolic filling/pressure
• ventricular remodeling via hypertrophy and dilation- ventricular hypertrophy, myocardial damage, fibrosis
• tachycardia

Question 7

Sympathetic Branch ANS

Answer 7

• preganglionic neurons originate in throacic and lumbar spinal cord
• ganglia located near spinal cord
• 1:10 ratio of pre to post ganglionic neurons
• neurotransmitters
  
  • norepinephrine- inc. BP
• drugs:
  
  • atropine- muscarinic M2 antagonist in heart- inc. HR
• opposing effects with parasympathetic enable homeostasis

Question 8

Parasympathetic Branch ANS

Answer 8

• preganglionic neurons originate in brainstem and sacral spinal cord
• ganglia located near target organs
• 1:3 ratio of pre to post ganglionic neurons
• neurotransmitters:
  
  • Acetylcholine- dec. BP
• drugs:
  
  • proranolol- beta-adrenergic antagonist in heart- dec. HR
• opposing effects of sympathetic enable homeostasis

Question 9

Autonomic Nervous System Homeostasis

Answer 9

• maintains homeostasis via widespread and complementary actions on organ systems in response to sensroy stimuli
• sympathetic and parasympathetic control of HR and force of contraction
• baroreceptor reflex
  
  • low BP- inc. sympathetic output
  • high BP- inc. in parasympathetic output
• humoral response to low BP

Question 10

Hypothalamus

Answer 10

• humoral responses to low BP are controlled by hypothalamus
• controls release of hormones via pituitary
• coordinates ANS and humoral response