Control of breathing Central rhythm Lecture 13 Flashcards

1
Q

Describe the muscles used in breathing

A

Inspiration- diaphragm is the only major inspiratory muscle External muscles- scalene and sternocleomastoid muscle used in exercise, coughing and vomiting Expiration- passive diaphragm relaxation Internal muscles- abdominal and oblique muscle involved only in forced breathing

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2
Q

Briefly describe central control of timing breathing and rhythm

A

PRG in the pons important for timing DRG and VRG in the medulla important for rhythm generation DRG- inspiratory neurones, in the nucleus tractus solitarius (NTS)- spontaneous activity synchronised with breathing VRG- inspiratory/expiratory motor neurones, activity in the DRG excites inspiratory neurones and inhibits expiratory neurones

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3
Q

What causes inspiration during quiet breathing?

A

DRG- self-excitable neurones, repetitively generating action potentials to cause inspiration ➡️C spinal cord ➡️phrenic nerves ➡️diaphragm contracts ➡️inspiration

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4
Q

What causes expiration?

A

Entirely passive DRG inactive➡️ diaphragm relaxes➡️ expiration

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5
Q

What neural control causes forced breathing?

A

Inspiratory neurones in the VRG via the T spinal cord causes other inspiratory muscles to contract Expiratory neurones causes expiratory muscles to contract

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6
Q

Describe the involvement of higher brain centres in respiration

A

Hypothalamus- temperature, fight/flight response Limbic system and cerebral cortex- emotion/pain Motor cortex- limb receptors, excercise

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7
Q

Give a brief overview of CNS in respiratory control

A

Brainstem- automatic- metabolic Cortical- voluntary- behavioural

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