Reticular Formation

Reticular Formation

\- consists of a deeply placed continuous network of nerve cells and fibers that extend from the spinal cord through the medulla, pons, midbrain, subthalamus, hypothalamus, and the thalamus

\- has a direction connections with the limbic system, thalamus, hypothalamic, and subthalamic regions

\- receives input from most of the sensory systems and has efferent fibers that descend and influence nerve cells at all levels if the central nervous system

Median Column

intermediate layer

Medial Column

large layer

Lateral Column

small layer.

Afferent Projections

receives impulses from different parts of the brain to the reticular formation.

F

T/F Reticular formation has no function in visual impulses or eye coordination.

T

T/F Reticular Formation is responsible for emotional facial expression and movement of muscle in response to emotion.

* Spinal Cord
* Cranial Nerve Nuclei
* Cerebellum

afferent connections of the reticular formation.

Efferent Projections

connections from the RF to different parts of the brain.

* Brainstem
* Spinal Cord

efferent connections of the reticular formation. 

* Reticulobulbar
* Reticulospinal
* Vestibulospinal

these tracts are responsible for maintenance of balance and postural adjustment during perturbation.

* Control of skeletal muscle
* Control of somatic and visceral sensations
* Control the ANS
* Control of the endocrine nervous system
* Influence on the biological clock
* Reticular Activating System

functions of the reticular formation.

Reciprocal Inhibition

\- coined by Margaret Rood

\- a smooth, alternating contraction and relaxation of the antagonistic and agonistic muscles for movement

\- modulated by the reticular formation

Co-contraction

\- happens when both agonist and antagonist muscles are contracted

\- for stability

Vestibular Spinal Tract

\- maintaining the tone of the antigravity muscles during anti-gravity positions, like standing

\- for stability

Vestibular Nuclei

nuclei responsible for balance and equilibrium.

T

T/F The reticular formation controls the amount of noxious stimuli or pain, either facilitatory or inhibitory, that enters or exits the somatic sensation or visceral sensation.

F

T/F The reticular formation is not responsible for the control of the respiratory muscles.

F

T/F The reticular formation has no direct neuronal fiber going to the hypothalamus, therefore it has no control of the ANS.

T

T/F The reticular formation helps the hypothalamic nuclei to control the activity of the hypophysis cerebri/hypothalamus

Alert

\- the patient is awake and attentive to normal levels of stimulation

\- interactions with the therapist are normal and appropriate

Lethargic

\- the patient appears drowsy and may fall asleep if not stimulated in some way

\- interactions with the therapist may get diverted

\- have difficulty in focusing or maintaining attention on a question or task

Obtunded

\- the patient is difficult to arouse from somnolent state and is frequently confused when awake

\- repeated stimulation is required to maintain consciousness

\- interactions with the therapist may be largely unproductive

Stupor

\- patient responds only to strong, generally noxious stimuli and returns to the unconscious state when stimulation is stopped

\- when aroused, patient is unable to interact with the therapist

Coma

\- patient cannot be aroused by any type of stimulation

\- reflex motor responses may or may not be seen

Arousal

response of the patient to a noxious stimuli.

Reticular Activating System

responsible for arousal and the levels of consciousness.

F

T/F State of consciousness is not dependent on the continuous projection of sensory information to the cortex.