-
Describe the midbrain.
- Most complex and integrative portion of brain stem.
- Can direct complex motor patterns at subconscious level.
- Influences activity level of entire nervous system.
-
What are the components of the mid brain?
- Corpora quadrigemina
- Cerebral peduncles
- Red nucleus
- Reticular Formation & Reticular Activating System
-
What makes up the Corpora quadrigemina?
- Superior colliculus
- Inferior colliculus
-
What is the function of the superior colliculus?
- Receives visual inputs from thalamus.
- Controls reflex movements of eyes, head, and neck in response to visual inputs.
-
What is the function of the inferior colliculus?
- Receives auditory data from nuclei in medulla oblongata and pons.
- Controls reflex movements of head, neck, and trunk in response to auditory inputs.
-
What is the function of the cerebral peduncles
Main motor pathway between cerebrum and lower parts of the nervous syste.
-
What is the red nucleus and what is its function?
- Receives information from cerebrum and cerebellum.
- Issues commands that affect upper limb position and background muscle tone.
-
What are Substantia nigra?
They are dark cells that adjust basal nuclei activity in cerebrum, found in the red nucleus.
-
What is the Reticular Formation & Reticular Activating System (RAS)?
- Consists of nuclei of gray matter found in the brain stem (medulla, pons, midbrain).
- Radiating axon fibers extend from the reticular formation to neurons in the diencephalon (thalamus & hypothalamus), basal nuclei of cerebrum, cerebellum, cerebral cortex
-
Describe the relationship of the RAS and the cerebral cortex.
- when sensory impulses reach the reticular formation axons, RAS stimulates the cerebral cortex into a state of consciousness and wakefulness.
- inhibition of RAS causes sleep
- if RAS or connections to it are damaged, or the cerebral cortex is damaged, the cortex cannot be aroused to a conscious state = coma
|
|
