Additional Structure Details Flashcards
Mpre details in understanding the Brainstem Pathology
What is a Pineal Body?
A small endocrine gland, considered to be part of the epithalamus
Where is the Pineal Body located?
Part of the epithalamus, located midline between the 2 Thalami
What does the Pineal Body do?
It produces melatonin
Its function is to help regulate sleep patterns
Where are the cerebral Peduncle
In the anterior 2/3 of the midbrain
Midbrian:
Cerebral Peduncle: crus cerebri(ventral)+tegmentum
Tectum
Where is the Olivary Nucleus
The olivary nucleus is located in the anterior medulla
What is the Superior Olive
Part of the auditory system connections
It aids in the perception of sound
What’s the inferior olive
The inferior olive has close connections with cerebellum
The inferior olive is the origin for the climbing fibers.
What is the function of the inferior olive?
It has functions in motor learning and coordination.
Where is the substantia nigra?
It is part of the Basal Ganglia.
It is located in the midbrain between the tegmentum.
What are the two parts of the substantia nigra?
The Pars Compacta which produces dopamine and
The Pars Reticula which is the Basal Ganglia Output
Reticular FOrmation
Consist of >100 small neural networks with varied functions
What does the function of the Reticular formation
Somatic Motor Control Cardiovascular COntrol Pain Modulation Sleep and Consciousness Habituation
Reticular Formation Somatic Motor Control
-Reticulospinal motor neurons. Maintaining tone,
balance & posture, particularly during body
movements.
- Relays eye and ear signals to the cerebellum so
that the cerebellum can integrate visual, auditory,
and vestibular stimuli in motor coordination
- Gaze centers. Enable eyes to track and fixate
objects
- Central pattern generators. Produce rhythmic
signals to the muscles of breathing and swallowing
Reticular formation Cardiovascular Control
Includes the cardiac and vasomotor centers
Reticular Formation Oain Modulation
Receives pain signals from the body
origin of descending analgesic pathways
can act on spinal centers to block pain signal conduction to the brain
Reticular Formation
Sleep and consciousness
Has projections to the thalamus and cerebral cortex, which allow it to influence our conscious attention
plays a central role in states of consciousness(alertness and sleep) Injury can result in a coma.
Reticular Formation
Habituation
the process by which the brain learns to ignore repetitive, meaningless stimuli while remaining sensitive to others
Example–live in the city and sleep through traffic but wale to an alarm or crying baby.
Modulate the activity of the cerebral cortex via the RETICULAR ACTIVATING SYSTEM
Reticular Activating System
Modulates the activity of the cerebral cortex
What are the component parts of the Reticular activating system
The Reticular formation, PPN and Locus Ceruleus
PPN-Peduncolopontine Nucleus
First discussed in Basal Ganglia lecture
Major group of nuclei in the reticular
formation
Located in midbrain, caudal to substantia
nigra
What does the PPN produce
Acetylcholine
What is the function of the PPN
Functions:
◦ Sensory feedback to cortex → motor planning and
coordination via globus pallidus & subthalamic nucleus
◦ Arousal, attention
◦ Motor learning & response to reward
Locus Ceruleus
Located in the upper pons/lower medulla
Part of the Reticular Activating system
What does the Locus Ceruleus produce
Norepinephrine
What is the function of the Locus Ceruleus
Involved with physiologic response to stress & panic Influences: neuroplasticity, arousal, sleep/wake cycles, attention & memory, emotions
Raphe Nuclei
Produces Serotonin—a monoamine neurotransmitter
Many consider part of the reticular formation
Red Nucleus
Located in the midbrain
Part of the Rubrospinal Tract
What is the function of the rubrospinal tract
Indirect motor pathway ◦ Function: Motor coordination Has connections with the cerebellum Babies’ crawling UE swing in gait limb control – not well defined and conflicting reports Proximal versus distal control
