Neural control

Question 1

brainstem death

Answer 1

Heart may still beat, chest rises and falls but no brain life

Question 2

Ondine’s curse

Answer 2

• Stop thinking about breathing means you die
• Impairs automation of breathing
• Phrenic nerve-diaphragm pacer possible treatment

Question 3

Injury to S2-3-4

Answer 3

Dimisnhed cough reflex, no innervation to pelvic floor

Question 4

T1 injury

Answer 4

Weak intercostal muscles (diminished respiration) and removes innervation to cardiovascular system

Question 5

Damage to cervical spine

Answer 5

Loss of autonomic supply to blood vessels = decreased BP

Question 6

C3-4-5 damage

Answer 6

No phrenic nerve = respiratory arrest

Question 7

Pontine respiratory group

Answer 7

Located in pons
Pneumotaxic centre: ‘switch off’ button at the end of inspiration, takes input from lung stretch receptors
Apneustic centre: controls breathing depth

Question 8

Ventral respiratory group

Answer 8

• Nucleus ambiguus
• Efferent role
• Forced inspiration and expiration
• botzinger complex: expiration
• Intermediate VRG: motor neurons for larynx, pharynx and trachea
• Rhythmic respiration initiated by re-Bötzinger complex

Question 9

Dorsal respiratory group

Answer 9

• Nucleus solitarus
• Afferent - receives sensory info from CN9 and 10
• Quiet/passive inspiration

Question 10

Vasoconstrictor area

Answer 10

Travels down spinal cord to constrict vessels increase HR and force

Question 11

Vasodilator area

Answer 11

Inferior medulla

Inhibits vasoconstrictor centre

Question 12

Sensory area

Answer 12

Tractus solitaries nucleus
Posteriolateral medulla
Circulatory signals from vagus and glossopharyngeal

Question 13

Cardioacceleratory centre

Answer 13

Dorsal medulla
Sympathetic ns
Increases HR and force

Question 14

Cardioinhibitory area

Answer 14

Nucleus ambiguous and dorsal nucleus

Parasympathetic NS

Question 15

Reticular formation

Answer 15

• Area of brain that controls blood vessels

- PS impulses down vagus nerve and sympathetic via spinal cord (thoracolumbar spine)

Question 16

Neural regulation of heart

Answer 16

• SAN (adjavent to SVC, lateral to RA) → AVN (posterior to tricuspid valve, delays impulse so atria can contract)
• Heart can beat by itself
• Sympathetic nerves increase the rate and strength of contraction
• Parsympathetic NS: CNs 3,7,9,10 and nerve roots S2-4
• Sympathetic nerves supply arteries - small arteries and arterioles, no p/s control of vessels
• cn1-4 from midbrain or above, 5-8 come out pons and 9-12 from medulla

Question 17

CN10 testing

Answer 17

• Pt voice quality
• Elevation of soft palate and uvula when speaking
• Gag reflex motor

Question 18

Cn10 motor supply

Answer 18

• Palate
• Pharynx
• Larynx

Question 19

CN10 sensory supply

Answer 19

• Tympanic membrane
• External auditory canal
• Ear

Question 20

CN10 course

Answer 20

• Medulla
• Jugular foramen
• In the cranium, auricular branch arises
• Right vagus nerve passes anterior to subclavian artery and posterior to sternoclavicular joint
• Left vagus nerve passes inferiorly between left common carotid and left subclavian arteries posterior to sternoclavicular joint
• In thorax, right forms posterior vagal trunk and left forms anterior vagal trunk
• In abdomen, trunks terminate by dividing into branches that supply oesophagus, stomach and bowels

Question 21

CN9 testing

Answer 21

• Sensory part of gag reflex
• Ask to cough and swallow water
• Say aaaaahhhhh and look for uvula deviation

Question 22

CN9 autonomic supply

Answer 22

Salivary glands

Question 23

CN9 motor supply

Answer 23

Stylopharyngeus

Question 24

CN9 sensory supply

Answer 24

Posterior third of tongue, pharynx, middle ear