Quiz 2 (suzanne's) Flashcards
What structure is located under the cerebrum and above the brain stem?
Diencephalon
What is RAS?
Reticular Activating System
- It projects sensory axons to the cerebrum.
- RAS is important in maintenance of consciousness, awakening from sleep, autonomic reflexes: heart rate,blood pressure.
- RAS is, probably, involved in pain relief as well.
Was does RAS do?
- projects sensory axons to the cerebrum.
- maintenance of consciousness, awakening from sleep
- autonomic reflexes: heart rate, blood pressure.
- probably, involved in pain relief as well.
What is reticular formation?
Net-like mesh of neuron bodies (soma) and axons.
- Extends from the upper part of the spinal cord to the diencephalon via brain stem
- Has both sensory and motor parts
What does the troclear nerve do (cranial nerve IV)?
- Controls Superior Oblique Eye Muscle
- Moves the eye ball medially and down
What does cranial nerve III (oculomotor) do?
- Controls all extra-ocular muscles but lateral rectus and superior oblique mm.
- Moves eye medially, up, down, elevates the upper lid.
- pupil constriction–lens accommodation for near vision (pupillary and accommodation reflexes)
What is Periaqueductal (central) gray?
Neuron cluster, surrounding the cerebral aqueduct
- part of Reticular Formation
- “Grand Central” of all sensory and motor tracts along the brainstem.
- Periaqueductal gray is important in pain perception and pain modulation
Where is the substantial nigra?
At the base of each cerebral peduncle.
-Functionally part of basal ganglia.
What is the superior coliculli.
- reflex centers for vision (eye tracking of moving objects; eye scanning of stationary images/ reading)
- adjustment of the pupil size and lens shape (pupilary and accommodation reflexes)
- reflexes of a corresponding eye, head, and neck movement
What is the inferior colliculi?
Part of the auditory pathway/ tract
-Originate and control reflex for sudden head / body movement, when one is
startled or surprised.
What are the cerebral peduncles?
They represent the anterior part of the midbrain.
- Hold and Support cerebral hemispheres, like two pillars.
- Tracts which connect the cerebrum with the pons, medulla oblongata and spinal cord.
- At their base substantia nigra.
What are major S/S of Parkinson’s disease?
Resting tremor
Bradykinesia–slowness mvmt
Hypokinesia–decreased mvmt
Muscular rigidity
Delayed initiation and termination ofmovements
Dementia / Loss of content of consciousness
The Midbrain (Mesencephalon)
Situated between the pons and diencephalon (everything with the root “thalamus”).
-Contains nuclei and tracts.
-Divided on posterior and anterior parts by the cerebral aqueduct (pathway for
cerebro-spinal fluid or CSF from 3rd to 4th ventricle)
What is RF?
Reticular formation
Where is the Subthalamus located?
Situated under the thalamus (“like a saucer plate under the saucer”)
Consists of tracts and a pair of subthalamic nuclei
What is Cranial Nerve IV?
Troclear nerve
What does the subthalamus do?
It coordinates movement (Along with Red nuclei and Substantia nigra of
the midbrain)
If injured: violent ballistic movements. Involuntary violent mvmts.
(hemiballismus) could develop on the opposite site of the lesion.
Thalamus
Two oval- shaped nuclei: one in each hemisphere
Connected by the intermediate mass
80% of the diencephalon
Major SENSORY and motor relay/ switch center
Surrounded by Basal Ganglia and LimbicSystem nuclei
What are the functions of the thalamus?
Major relay station for sensations of touch, taste, smell, visual, auditory, and temperature from the body to the brain cortex
Relays motor commands between the cerebellum, basal ganglia and cerebrum
Relays impulses within the cerebral cortex for planning and execution of movement
Contributes to autonomic function regulation of”Zang/ Fu” organs (cardiac
What is the oculomotor?
Cranial nerve III
Hypothalamus
Located inferior and anterior to the thalamus
It is a conglomerate of multiple nuclei
Forms the roof and ventro-lateral walls of the third ventricle
Has connections with the pituitary, limbic system, thalamus, autonomic nervous system and other parts of the brain
Major center of homeostasis regulation
Endocrine system’s control starts here
Hypothalamus is in charge of temperature, reproduction, libido, hunger and thirst, sleep/wake, emotions, endocrineregulation
Supra optic: hypothalamic nuclei
Situated above the optic nerve.
Regulates blood pressure and blood volume
Secretes ADH (Anti-Diuretic Hormone) via axons
Posterior Pituitary (AKA Neurohypophysis) via vessels of hypophyseal portal system into the blood circulation Kidney water conservation
The stimulus for supraoptic nucleus: increase of the blood osmolarity
Paraventricular Nucleus
Secretes the hormone Oxytocin
Oxytocin is needed as per contraction of the uterine muscle to expel a product of conception; for contraction of smooth muscle of the breast milk ducts during breast feeding
Anterior and PosteriorHypothalamic Nuclei
Overall setting of a “Thermostat” for the temperature control and a Fever execusion, when needed.
What is the pineal gland?
The endocrine gland: secretes melatonin (sleep hormone) and serotonin (“comfort” neurotransmitter/ hormone). Also secretes CCK.
What does arcuate nucleus do?
Hormones that affect endocrine.
Produces major regulatory hypothalamichormones, regulating anterior pituitary (Adenohypophysis) activity: - TRH - GHRH - GnRH - CRH - Somatostatin - PIF