Heart Test #2 Flashcards

1
Q

What does cardiac output measure?

A

a measure of how hard the heart is working?

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What is cardiac output?

A

the volume of blood ejected from the left ventricle, into the aorta each minute

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What is the formula for cardiac output (CO)?

A

CO = SV (stroke volume) x HR (heart rate)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Stroke volume unit of measure

A

SV : stroke volume (ml/beat)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Heart rate unit of measure

A

HR : heart rate (beats per minute)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

The Franklin-Sterling Law states….

A

The more the heart is stretched (i.e. filled with blood), the harder it will contract, forcing more blood out

Cardiac output
Venous return

Affects stroke volume

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What is venous return?

A

rate of blood flow back to the heart

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What regulates the heart rate?

A
  • autonomic control and chemical regulation
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Where is the autonomic control center located?

A

the medulla oblongata

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What does the autonomic control center/medulla oblongata receive messages from?

A

Proprioceptors (body position)

Chemoreceptors (O2 , CO2 , pH)

Baroreceptors (blood pressure)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Chemoreceptors detect what?

A

changes in the chemical composition of the blood

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What are the two branches of the autonomic nervous system?

A
  • parasympathetic nervous system
  • sympathetic nervous system
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Sympathetic nerves run from _______________ _______________ to the _____________

A

medulla oblongata, SA node

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What neurotransmitter is used by the sympathetic nervous system?

A

norepinephrine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What is norepinephrine’s effect on heart rate?

A
  • increases the amount depolarization occurs (more “+”)
  • decreases the amount of times repolarization occurs
  • thus increasing the heart rate
  • increases Ca+2 entry, increasing the force of contraction
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

The vagus nerve (X) acts as what for the parasympathetic nervous system?

A

the main component of the PSNS/contains the main nerves of the PSNS

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What neurotransmitter does the parasympathetic nervous system release?

A

acetylcholine (ACh)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What is acetylcholine’s effect on heart rate?

A

Hyperpolarization of SA node (more “-“)

-takes longer to depolarize

thus heart rate slows

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What two components are involved in chemical regulation?

A

hormones and ions

20
Q

What hormones increase heart rate?

A

epinephrine and thyroid hormone

21
Q

What ion increases heart rate?

A

Ca2+

22
Q

What ion decreases heart rate?

A

Na+ and K +

23
Q

In what ways is a fetus dependent on the mother?

A
  • Fetal lungs, kidneys and GI tract are nonfunctioning
  • O2 and nutrients come from mother’s blood
  • CO2 and wastes are passed to mother’s blood
24
Q

What is the placenta?

A

a disc of tissue that connects a mother’s uterus to the umbilical cord, and is ultimately responsible for delivering nutrients and oxygen to a fetus

25
Q

The placenta acts as what organs for the fetus?

A

lungs, kidneys and GI tract of fetus

26
Q

What is the relationship between the placenta and blood vessels?

A
  • the placenta contains both the mother and fetus’s blood vessels
  • blood vessels do not connect, but just lie close to one another
27
Q

What process does the placenta/fetus use to transport O2, nutrients, and waste products?

A

diffusion

28
Q

What’s different about fetal hemoglobin?

A

Fetal Hemoglobin has higher affinity for O2 than mother’s Hb (speeds up transfer of oxygen from mother to fetus

29
Q

What does the umbilical cord connect?

A

connects fetus to the placenta

30
Q

What does the umbilical cord contain?

A

2 umbilical arteries
- from fetus to placenta
- carry low O2 blood

1 umbilical vein
- carries high in O2 blood back to fetus

31
Q

What does the umbilical vein join?

A

the portal and inferior vena cava

32
Q

What are the fetal differences in blood flow?

A

Some blood (already oxygenated) from right atrium passes directly to left atrium through foramen ovale (whole between left and right atrium)

Remaining blood in rt atrium passes to rt ventricle and then enters the pulmonary artery

Much of the blood entering pulmonary artery passes through the ductus arteriosus (connects pulmonary trunk to aorta) to the aorta

Only a small portion of blood in pulmonary artery goes to lungs (nonfunctional) (are growing organs that still need oxygen from the blood)

33
Q

What parts of the fetus change at birth?

A
  • lungs
  • foramen ovale
  • ductus arteriosus
  • umbilical arteries
  • umbilical vein
34
Q

Fetal changes at birth: lungs

A

Lungs inflate and become functional

35
Q

Fetal changes at birth: foramen ovale

A

foramen ovale gradually closes to become fossa ovalis (indent)

36
Q

Fetal changes at birth: ductus arteriosus

A

Ductus arteriosus closes and becomes ligamentum arteriosum

37
Q

Fetal changes at birth: umbilical vein

A

Umbilical vein becomes round ligament (belly BUTTON)

38
Q

Fetal changes at birth: umbilical arteries

A

Umbilical arteries become lateral umbilical ligaments

39
Q

What is the cause of the phenomenon known as “blue babies”?

A

failure of foramen ovale/ductus arteriosus to close causing blood to not become fully oxygenated

40
Q

What are the common heart problems?

A
  • Heart murmur
  • Atherosclerosis
  • Ischemia
  • Myocardial infarction
41
Q

Heart murmur

A
  • Heart valve does not completely close
  • Allows some backflow of blood (regurgitation)
  • Common, but usually not serious
42
Q

Atherosclerosis

A
  • blockages of coronary circulation
  • fatty substances deposited in arteries (inadequate blood flow)
  • can cause inadequate blood supply to heart muscle
43
Q

Atherosclerosis can lead to what?

A

Ischemia

44
Q

Ischemia

A
  • Reduced O2 supply weakens heart cells
  • Angina pectoris (chest pain: “stop these activities”)
45
Q

Myocardial infarction

A
  • aka a HEART ATTACK
  • Depending on extent of damage, can cause heart cells not to beat in synchrony (fibrillation)
  • Dead tissue is replaced by noncontractile scar tissue (heart mad weak now)
46
Q

How do defibrillators work?

A

cause a unison depolarization of the heart to attempt to make it contract/beat again