Neural Control of Blood Pressure Flashcards
Which of these is NOT a key central station of baroreceptor control?
a. Rostral ventrolateral medulla
b. Sympathetic preganglionic neurons within intermediolateral nucleus or spinal cord
c. Nucleus of the solitary tract
d. Nucleus ambiguus
e. caudal ventrolateral medualla
d. Nucleus ambiguus
Nucleus ambiguus innervates the muscles of the soft palate, pharynx, and larynx. All others are considered key central stations of baroreceptor control.
What would be the result of a lesion in the nucleus of the solitary tract?
a. hypertension
b. hypotension
c. no change
a. hypertension
Lesions of the NTS result in hypertension and a loss of the baroreceptor reflex.
Which region of the Nucleus of the Solitary Tract is targeted by nodose ganglia afferents?
a. caudal
b. intermediate
c. rostral
b. intermediate
Caudal input is related to chemoreceptors/respiration, rostral input to gustatory innervation.
What would be the effect of NBQX (AMPA antagonist) on input from solitary tract (ST) neurons to the nucleus of the solitary tract?
a. increased transmission
b. inhibited transmission
c. neither
b. inhibited transmission
ST neurons communicate via glutamatergic transmission with upstream neurons in the NTS. NBQX blocks glutamatergic transmission by antagonising AMPA receptors.
Match baroreceptor fibre types for reflex and tonic BP control with their characteristics.
a. lower sensitivity
b. sudden onset discharge
c. wide operating range
d. rapid conduction velocity (a fibres)
e. delayed onset discharge
f. slow conduction velocities (c fibres)
g. narrow operating range
h. higher sensitivity
Reflexive control:
h. Higher sensitivity
b. Sudden onset discharge
g. Narrow operating range
d. Rapid conduction velocities (A fibers)
tonic control:
a. Lower sensitivity
e. Delayed onset discharge
c. Wide operating range
f. Slow conduction velocities (C fibers
What is the effect of vasopressin on ST transmission?
a. decreases
b. enhances
c. no effect
a. decreases
What is the effect of oxytocin on ST transmission?
a. decreases
b. enhances
c. no effect
b. enhances
How are NTS-CVLM projecting neurons connected?
a. polysynaptically
b. monosynaptically
c. they’re not connected
b. monosynaptically
What cell type is the caudal ventrolateral medulla primarily composed of?
a. glutamatergic
b. GABAergic
c. both
b. GABAergic
The caudal ventrolateral medulla (CVLM) contains GABAergic neurones that tonically inhibit presympathetic RVLM neurons.
What is the consequence of a lesion in the CVLM? (you can choose more than one)
a. hypotension
b. hypertension
c. tachycardia
d. bradycardia
a. hypertension
b. tachycardia
Without the tonic inhibition from CVLM neurons blood pressure and heart rate increases.
C1 RVLM cells are primarily required for :
a. tonic blood pressure control
b. nothing, they are not involved in blood pressure control.
c. reflexive blood pressure control
c. reflexive blood pressure control.
Reflexive blood pressure control is C1-mediated.
Which of these has been suggested as a potential source for RVLM vasomotor tone generation?
a. nucleus of the solitary tract
b. lateral tegmental field
c. caudal ventrolateral medulla
b. lateral tegmental field
Which of these statements is INCORRECT:
a. decreased activity in the NTS is correlated with increased activity in the RVLM
b. decreased activity in the CVLM is correlated with increased activity in the RVLM
c. increased activtiy in the NTS is correlated with increased activity in the RVLM
c. increased activtiy in the NTS is correlated with increased activity in the RVLM
Increases in muscle sympathetic nerve activity correlate with decreased intensity (i.e. activity) in NTS and CVLM, with concomitant increase in intensity (i.e. activity) in RVLM
How is vasomotor maintained following a RVLM lesion?
a. CVLM transmission
b. vasomotor cannot be maintained
c. plasma hormones (vasopressin)
c. plasma hormones (vasopressin)
What are 2nd order baroreceptor neuron characteristics?
a. low chatter, instable firing rates
b. high chatter, robust firing rates
c. low chatter, robust firing rates
c. low chatter, robust firing rates
