Week 8- Breathing Flashcards

1
Q

Muscles of Respiration

A
  • Intercostal muscles
    • Internal
    • External
  • Diaphragm
  • Accessory muscles
    • sternocleidomastoid
    • scalenes
    • abdominal
    • pectoralis minor
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Inspiration

A

Based on pressure changes
- Happens when the atmospheric pressure is higher than the intrathoracic pressure. Pressures naturally will move from high to low
- Active

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

Expiration

A
  • Based on pressure changes
  • Happens when the atmospheric pressure is lower than the intrathoracic pressure
  • Passive
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Control of Breathing

A
  • Respiratory centre in the brain stem
  • Groups of neurons in the pons and medulla
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Inspiratory Center:

A
  • Thought to be the “pacemaker” of the respiratory control centre
  • Rhythmically depolarize and send impulses via: the phrenic nerve to the diaphragm and intercostal nerves to the external intercostal muscles
  • Muscles contract - inspiration
  • When they stope sending impulses - relaxation and expiration occurs
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Expiratory Center:

A
  • When deeper and more forceful expiration is required - frequency of impulses is increased
  • Impulses to the internal intercostal and abdominal muscles - forceful expiration
  • Not involved during normal breathing, only active when the expiratory muscles are needed during forced expiration
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Pons Respiratory Centre

A
  • Coordinates actions of the Medullary Centre to produce a smooth breathing process
  • 2 types of neurons: stimulating neurons, inhibitory
  • Either increase or decrease the depth and length of inspiration
  • Homeostatic balance of rate and depth respirations
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What are some factors that influence the Respiratory Center?

A
  • Direct stimulation
  • Stimulation through sensors
  • Cause adjustments to the rate and depth of respirations
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Factors that Influence Breathing

A
  • Feedback to the medulla comes from sensors throughout the nervous system (eg. changes in PO2, PCO2 & PH (hydrogen ions))
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

PCO2 acts on chemoreceptors located in the medulla

A
  • sensitive to the changes in CO2 and H+ (pH) in arterial blood
  • Normal range of PCO2 is 38-40 mmHg
  • Stimulation of these chemoreceptors by increased PCO2 results in faster breathing and greater volumes of air moving in and out of the lungs per minute
  • Decreased PCO2 results in inhibition of the medulla rhythmicity and slows the respiration
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Arterial Blood Pressure

A
  • Arterial BP helps control breathing by acting on carotid and aortic baroreceptors
  • Rise in arterial BP creates a slowing of the RR
  • Sudden drop increases the rate and depth of respirations
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Cerebral Cortex

A
  • Impulses from the motor area of the brain to the respiratory centre may increase or decrease respirations voluntarily (have the ability to control it)
  • While you may have the ability to control it to a certain extent- the automaticity of the system will eventually pick up
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Inflation/ Deflation Reflex

A
  • Stretch receptors in the visceral pleura are sensitive to the degree of stretching of the lungs
  • During inspiration impulses are sent directly to the respiRatory centre via the vagus - inhibits impulses - promotes expiration and deep inspiration
  • Hering-Breur reflex regulates the depth and rhythmicity of respiration and thus the Tidal Volume and prevents over inflation
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

How does Hering-Breur work?

A
  • When the tidal volume of air has been inspired, the lungs are expanded enough to stimulate the stretch receptors located within them
  • The stretcher receptors then send inhibitory impulses to the inspiratory centre and relaxation of the inspiratory muscles occur and expiration begins
  • One expiration is done, the reflex is stimulated again and inspiration occurs again
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Higher-brain centres

A
  • Involuntary during periods of anxiety, fear, pain, excitement, or temperature, via the hypothalamus
  • Voluntary alteration of respiratory patterns (provided by cerebral cortex and can be overridden by the chemoreceptors)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Body Temperature

A

Increases in temperature increases the rate of breathing
- Increase in temperature causes O2 to be released from hemoglobin
- Exercise or fever

Decrease in temperature decreases the rate
- Hypothermia
- Decrease in temperature causes metabolism to slow doen- decreased need for O2