Physio Lecture 52

Front 1

Discuss the schematic representation of the respiratory control system.

Back 1

The respiratory control system is made of a controller (cerebrum, brain stem, spinal cord), effectors (lungs and muscles of respiration), and sensors (chemoreceptors).

Front 2

What is the minimal substrate for breathing?

Back 2

The medulla. This is because experiments lesioning the pons and above impacted breathing negatively, but it a lesion at the medulla results in the cessation of breathing.

Front 3

What would a lesion rostral to the pons do? What would a lesion at the rostral pons do? What would a lesion at the pontomedullary junction do? What would a lesion at the medulla/sc do?

Back 3

1) nothing
2) slow breathing and increase tidal volume
3) errating breathing
4) stop breathing

Front 4

What areas of the brain are involved in the control of breathing?

Back 4

The medulla and pons most importantly. (cerebellar hypothalmic and suprapontine can influence)

Front 5

When do respiratory neurons fire?

Back 5

Respiratory neurons fire during inspiration, late inspiration, or expiration.
A neuron may fire in an incremental or decremental activity manner. (ie a neuron firing in inspiration could start of firing slow but then pick up or the other way around).

Front 6

What is the VRG?

Back 6

The ventral respiratory group includes the nucleus ambiguous and retroambiguous which are sites of pump muscle and airway muscle pre motor neurons.

Front 7

What is the Pre Botz C

Back 7

This is a site critical for respiratory rhythm generation

Front 8

Which regions of the brain stem are for pattern generation?

Back 8

Parabracheal nucleus and Kollifer Fuse nucleus (PB and KF)

Front 9

What is the role of the NTS? What is the role of the RTN?

Back 9

First order chemoreceptor and proprioceptor sensory neurons is the NTS. The RTN is a chemoreceptor and integrator

Front 10

What is the difference between respiratory rhythm generation and respiratory pattern generation?

Back 10

Rhythm generation neurons provide the signal that initiates the respiratory cycle as intrinsic oscillating neurons. Rhythm generator neurons activate rhythm pattern neurons, which then activate respiratory pump and airway motorneurons.

Front 11

What is the difference between a pacemaker model and a network model of respiratory rhythmogenesis?

Back 11

The pacemaker model- neurons spontaneously depolarize to generate the cycle.

Network - Through RECIPROCAL inhibition, a network of neurons may underlie respiratory rhythmogensis. Expiratory neurons have an inhibitory effect on inspiratory neurons during expiration and vice versa.

*NETWORK MODEL more strongly supported

Front 12

Describe breathing patterns with
1) intact medulla and pons
2) intact medulla and pons but vagotomy
3) intact medula, removed pons
4) intact medulla, removed pons and vagotomy
5) removed medulla and pons
6) removed medulla and pons, vagotomy

Back 12

1. Normal
2) Normal but slowed down
3) Somewhat normal (prolonged inspiration)
4) Slowed down greatly
5) gasp like breath
6) slowed down gasp like breath

Front 13

How are behaviors like sneezing, vomitting, coughing initiated?

Back 13

There is a trigger for your sneeze, cough, etc that goes to the integrator/pattern generator which then controls respiratory muscles to generate the desired action.

Front 14

What is the important point to note in terms of neuron firing in breathing vs vomitting

Back 14

Some medullary neurons contribute to multiple physiological behaviors. The firing pattern is slightly different between them (abd and diaphragm contracting at different times vs same time in vomitting)