Lec 15 Flashcards
What part of the brain connects the cerebrum, cerebellum, and spinal cord?
The brain stem.
What are the three pieces of the brain stem?
The midbrain, the pons, and the medulla oblongata.
What are the three main characteristics of the brain stem?
- It deals with rigidly programmed automatic behaviors necessary for survival.
- It is the pathway between higher and lower neural centers.
- It is associated with 10 pairs of cranial nerves.
What ventricular system runs through the midbrain?
The cerebral aqueduct does.
What structures at the top of the midbrain contain large pyramidal tracts? What are these tracts called?
The cerebral peduncles contain motor/corticospinal tracts.
What substance in the midbrain is involved in pain supression?
Periaqueductal grey matter.
What section of the midbrain consists of four parts? What are the four parts and their functions?
The Corpora Quadrigemina consists of two superior colliculi (visual reflex centers), and two inferior colliculi (auditory relay/startle).
In a cross section of the midbrain, what two nucleus are visible?
The substantia nigra and the red nucleus.
Why is the substantia nigra dark? What other part of the brain is it linked to?
It contains a lot of melanin, and is linked to the basal nuclei.
Why is the red nucleus called that? What does it do?
It has a rich vascular supply with iron pigment, and contains relaying nuclei for pathways influencing limb flexion.
What is the pons mostly made of?
Conduction tracts either vertically to connect the spinal cord with brain centers, or transversely to communicate with the cerebellum.
What three cranial nerves come from the pons? What structure on a pons cross section are they a part of?
Cranial nerves 5, 6, and 7 are part of the reticular formation.
What structure connects the pons to the spinal cord?
The medulla oblongata.
Which brain ventricle is contained within the medulla oblongata?
The fourth ventricle
What is a pyramid in the medulla oblongata? What is the significance of their organization?
Pyramids are large motor tracts that are decussated, meaning they cross over and are responsible for contralateral regulation.
What are the worm looking structures on the anterior side of the cross section of the medulla oblongata? What do they do?
The inferior olivary nuclei relay sensory info about muscles and joints to the cerebellum.
What nerves run through the medulla?
Cranial nerves 8, 9, 10, and 12.
What are the three structures within the medulla oblongata?
- The cardiovascular center
- The respiratory centers
- Other centers (hiccupping/swallowing/vomiting)
What is the main role of the medulla oblongata?
It is the reflex center for homeostasis.
What part of the brain works closely with the medulla oblongata? What is the relationship between them?
The medulla oblongata and hypothalamus work together to maintain homeostasis. The hypothalamus relays instructions through the medullary center which carries them out.
What is the purpose of the cerebellum?
The cerebellum processes input from the cerebral motor cortex, brainstem nuclei, and sensory receptors. It monitors the timing and patterns of skeletal muscle for smooth daily movements. “muscle memory”
What structure connects the two hemispheres of the cerebellum?
The vermis
What are the transverse fissures of the cerebellum called?
folia
What are the three divisions of a cerebellar hemisphere?
The anterior, posterior, and flocculonodular lobes.
What types of maps do the anterior and posterior lobes both have?
Sensory and motor maps of the body.
Does a part of the cerebellum that corresponds to a body part control the input of information or the output of information?
Both
What processes can be carried out due to the presence of multiple muscle maps in the cerebellum?
Coordination of proprioceptive information, planning information, and instructions to the motor cortex via the thalamus.
How do the cerebellar lobe muscle maps differ?
The anterior lobe has a full map of the body, and the posterior map has a split map of both arms and legs.
What part of the cerebellum is responsible for the trunk and girdle?
The medial portion.
What part of the cerebellum is responsible for the extremities and skilled movements?
The intermediate portion.
What part of the cerebellum is responsible for input from association areas and planning?
The lateral portions.
What are the flocculonodular lobes for?
They receive input form equilibrium sensors and deal with balance and some eye movements.
What structures move information towards and away from the cerebellum?
The cerebral peduncles.
What does it mean that the cerebellar peduncles are ipsilateral?
They deal with input/output on the same side of the body.