How breathing is started and adjusted: the brainstem centers that make the rhythm, the chemoreceptors that match it to blood CO₂, H⁺ and O₂, and the reflexes from the lungs and airways that fine-tune it. Neural regulation is the favourite long essay, with chemical regulation close behind, and short notes come from the brainstem centers and cuts, hypoxia, hypercapnia and the Hering–Breuer reflex.
Topics, in the book’s order
- Respiratory centers (neural control) · pp. 931–936 · asked 9 times
- Chemical control of breathing · pp. 937–942 · asked 5 times
- Non-chemical control: reflexes and sleep · pp. 942–945 · asked once
When you’ve read them: Quiz 108 · Regulation of Respiration, 15 questions.
After this chapter you should be able to
- name the respiratory centers of the medulla and pons, and say what each does
- describe what brainstem cuts or lesions at different levels do to breathing
- explain the part the vagus plays in controlling breathing
- describe the structure and work of the peripheral and central chemoreceptors
- describe the structure and functions of the carotid body
- explain how hypoxia, hypercapnia and acidosis change ventilation
- describe the breathing changes in metabolic and in respiratory acidosis
- name the respiratory reflexes and explain what each contributes
- set out the principles of neural, chemical and non-chemical regulation
Going further: the neural, chemical and non-chemical mechanisms in full detail, and the connections of the carotid body.
Viva checklist
- The medullary centers: where the DRG and VRG lie, and what each does
- Where the central pattern generator lies, and what it does
- The pneumotaxic and apneustic centers: sites, jobs, and how they work with the medulla
- What the vagus does to breathing, and what vagotomy does
- The result of brainstem cuts at each level, with and without vagotomy
- Hypoxia: its effect on ventilation, the mechanism, and why breathing rises little from 100 to 60 mmHg
- Hypercapnia: its effect on ventilation and the mechanism
- The central chemoreceptors, and why they sense H⁺ rather than CO₂ itself
- Breathing in metabolic acidosis and in respiratory acidosis
- Hormones that change breathing, and how
- Slowly adapting receptors; the Hering–Breuer inflation and deflation reflexes and their significance
- Rapidly adapting receptors and J receptors, and what they do
- Sleep apnea syndrome
- Why cough survives a lung transplant