5. Control and Regulation of Breathing

Flashcards about control and regulation of breathing.

Respiratory rate

Breathing frequency

Tidal Volume

Depth of breathing

Central chemoreceptors

Responsive to hydrogen ions, provides the primary drive for an animal to breathe

Peripheral chemoreceptors

Responsive to oxygen, carbon dioxide, and hydrogen ions

Pulmonary receptors

Sense stretch and irritants in the lungs

Joint and muscle receptors

Provide input on muscle stretch and tension

Medulla oblongata

Dorsal respiratory group (inspiration) and Ventral respiratory group (both inspiration and expiration)

Pons

Pneumotaxic centre and Apneustic centre

Dorsal Respiratory Group

Sets the general rhythm and frequency of inspiration

Basic rhythm generator (DRG)

Integrates afferent input and emits efferent bursts of inspiratory action potentials

Ventral Respiratory Group

Contributes to both inspiration and expiration, active during increased pulmonary ventilation

Pneumotaxic centre

Controls the point at which the ramp signal stops, regulates tidal volume and breathing rate

Apneustic Centre

Promotes inhalation via constant stimulation of neurons in the medulla oblongata

Cerebral Cortex

Can override the basic rhythm of the respiratory cycle by controlling the respiratory muscles

Hypothalamus and Limbic System

Can override the central pattern generator, usually during sympathetic fight or flight response

Peripheral Chemoreceptors

Detects oxygen changes in the blood and also responds to carbon dioxide and hydrogen ions; sensory cells are type I glomus cells

Ventilation-Perfusion Matching

Local control mechanisms attempt to match alveolar ventilation and perfusion to maximise gas exchange.

Local control in V/Q mismatch

Vasoconstriction of pulmonary vascular smooth muscle, diverts blood flow to better-ventilated alveoli

Sympathetic stimulation in the lungs

Activation leads to bronchodilation via β2‐adrenergic receptors

Parasympathetic stimulation in the lungs

Activation leads to bronchoconstriction via M3 muscarinic receptors