RETICULAR FORMATION

Question 1

The term reticular formation refers to a mass of neurons and nerve fibers extending from the caudal medulla to the rostral midbrain and continuous with the________ of the subthalamus and__________of the thalamus.

Answer 1

zona incerta

midline, intralaminar and reticular nuclei

Question 2

the reticular formation of the brain stem is divided into the following nuclear groups:

Answer 2

Median raphe: The neurotransmitter of most raphe nuclei is serotonin.

Paramedian reticular:lateral to the medial longitudinal fasciculus and the medial lemniscus

Medial reticular
Lateral reticular

Question 3

Raphe nuclei of the medulla oblongata receives inputs from

Answer 3

spinal cord, trigeminal sensory nuclei (second-order sensory input), and the periaqueductal gray matter of midbrain.

Question 4

The facilitatory input from the _________matter to the medullary raphe nuclei, and the inhibitory projections of the latter on _______constitute the anatomic substrate for the analgesic effect of electrical stimulation of the midbrain periaqueductal gray.

Answer 4

periaqueductal gray

spinothalamic neurons in the dorsal horn of spinal cord

Question 5

It becomes evident from their connections that the caudal raphe nuclei are involved in ______mechanisms while the ________are part of the reticular activating system concerned with wakefulness, alertness, and sleep.

Answer 5

pain

rostral raphe nuclei

Question 6

Descending projections from the medial group of reticular nuclei project to the spinal cord ____________

Answer 6

pontine and medullary reticulospinal tracts located in the ventral and lateral funiculi of the spinal cord

Question 7

MEDIAN GROUP)

The _________ projections of this group of reticular nuclei suggest a role in motor control, whereas the ascending projections relate these nuclei to _____________

Answer 7

descending

consciousness and alertness

Question 8

The ____________(paramedian reticular and reticulotegmental) receives inputs from the spinal cord (spinoreticular), cerebral cortex, and vestibular nuclei and project to the cerebellum.

Answer 8

paramedian group of reticular nuclei

Question 9

The _______in the medulla and pons (parvocellularis and lateralis) constitute the receptive component of reticular nuclei.

Answer 9

lateral group of reticular nuclei

Question 10

An expiratory center has been located experimentally within the ______of the medulla oblongata.

Answer 10

parvocellular reticular area

Question 11

The involvement of the __________in Parkinson’s disease may explain the autonomic disturbances that occur in that disease.

Answer 11

parabrachial nucleus

Question 12

Based on its connections, the_______ plays a role in integrating and gating activities of thalamic nuclei.

Answer 12

reticular nucleus

Question 13

Cholinergic neurons are found in two locations

Answer 13

(1) rostral pons-caudal midbrain, and

(2) basal forebrain.

Question 14

The _________ and the adjacent lateral dorsal tegmental nucleus lie within the tegmentum of the pontomesencephalic junction, dorsolateral to and overlapping the lateral margin of the superior cerebellar peduncle, between it and the lateral lemniscus.

They play roles in arousal and movement.

Answer 14

pedunculopontine reticular nucleus

Question 15

Neurons of the pedunculopontine nucleus are affected in patients with _______

Answer 15

progressive supranuclear palsy

Question 16

Dopaminergic neurons form small clusters at several brain loci. Many of these neurons are found in the _______ (ventral tegmental area of Tsai) and the _________

Answer 16

ventral tegmentum of the midbrain

adjacent substantia nigra (pars compacta).

Question 17

Noradrenergic neurons of the brain stem are divided into two major components.

The first is the norepinephrine system of the ___________The second is the ______________comprising another series of noradrenergic cell groups scattered in the pons and medulla (groups A1 to A7).

Answer 17

locus ceruleus (catecholamine neuron cell group A6)

lateral tegmental norepinephrine system,

Question 18

The rostral pontine and mesencephalic serotonergic raphe neurons project to the entire ________, whereas the caudal pontine and medullary serotonergic raphe neurons project to the ________

Answer 18

forebrain

cerebellum, medulla, and spinal cord

Question 19

The _________plays a role in psychiatric disorders (depression, obsession-compulsion, aggression, anxiety)

Answer 19

rostral raphe serotonergic system

Question 20

Inhibition of__________ in the raphe system leads to insomnia.

Answer 20

serotonin

Question 21

reticular formation functions

Answer 21

somatic motor, somatic sensory, visceral motor, and arousal and sleep functions.

Question 22

Somatic Motor Function: In general, the ________ exerts facilitatory influences, whereas the _____ exerts inhibitory influences.

Answer 22

pontine reticular formation

medullary reticular formation

Question 23

Somatic sensory: The analgesia produced by stimulation of the periaqueductal gray is mediated by facilitatory input from the periaqueductal gray to the _______

Answer 23

nucleus raphe magnus.

Question 24

Visceral Motor Function.

Stimulation of the __________in the medulla oblongata elicits an inspiratory response and depressor effect on the circulatory system

Answer 24

medial group of reticular nuclei

Question 25

A pontine reticular center (pneumotaxic center) which regulates respiratory rhythm has been identified in the area of _________ nuclei located dorsal to the motor nucleus of the trigeminal nerve.

Answer 25

parabrachial–Kölliker-Fuse

Question 26

Activity in the ascending reticular activating system is a ______ maintained by incoming afferent stimuli.

Answer 26

tonic one

Question 27

______plays a central role in selective awareness.

Answer 27

reticular nucleus

Question 28

phases of sleep:

Answer 28

(1) slow wave sleep and

(2) rapid eye movement (REM) or paradoxical sleep.

Question 29

SLOW WAVE SLEEP

Answer 29

Reduced muscle tone.
Drop in blood pressure, heart rate, and respiratory rate.
Synchronized slow EEG activity of high voltage; hence the name slow wave sleep.

Question 30

Stages of SLOW WAVE SLEEP
Stage I (drowsiness). This stage lasts from one to seven minutes. \_\_\_\_\_\_\_\_\_

Stage II (light sleep). Arousal in this stage needs more intense stimuli than in Stage I.

Stage III (moderately deep sleep). The EEG in this stage is characterized by the appearance of_______

Stage IV (deep sleep). Arousal from this stage requires strong stimuli.

Answer 30

1. The individual is easily aroused in this stage.

2. slow, high voltage waves.

Question 31

Sleep walking, bed wetting, night terrors, and seizures are known to occur in ______

Answer 31

slow wave sleep.

Question 32

_______sleep is also known as desynchronized sleep, active sleep, dreaming sleep, fast wave sleep, and deep sleep. It constitutes 25% of sleeping time in adults

Answer 32

REM (PARADOXICAL) SLEEP

Question 33

Features of REM sleep

Marked _____, especially in neck muscles, hence head drop in people entering this state while sitting up in a chair.

Increase in ______irregular and rapid respiration.

Erection in males.

Teeth grinding.

Dreaming, hence the name dreaming sleep.

Rapid eye movements _______ hence the name REM sleep.

Answer 33

hypotonia

blood pressure and heart rate;

(50 to 60 movements per min),

Question 34

It is easier to _____a person from REM sleep than from stage IV slow wave (non-REM) sleep.

Answer 34

awaken

Question 35

The first REM phase occurs about ______after sleep onset and lasts ______. Subsequent REM phases recur every 1 to 2 hours.

Answer 35

90 minutes

about 10 to 15 minutes

Question 36

_________suppress REM sleep but have little effect on stage IV of non-REM (slow wave) sleep. On the other hand, _________(Valium, Librium) suppress stage IV non-REM sleep and have less effect on REM sleep.

Answer 36

Barbiturates and alcohol

benzodiazepines

Question 37

It is now established that the ascending reticular activating system and cortical arousal are mediated via two systems:

A ______ from the pedunculopontine and laterodorsal tegmental reticular nuclei to several thalam-ic nuclei (intralaminar, relay, reticular) and from there, via thalamocortical projections, to the cerebral cortex. This system is active during_______

An ________from locus ceruleus (norepinephrine), raphe nuclei (serotonin), tuberomammillary nucleus (histamine) directly (without passing through the thalamus) to the cerebral cortex. This system is active during _______ but not during REM sleep.

Answer 37

cholinergic system

wakefulness and REM sleep.

aminergic system

wakefulness