Brain Structures & Cranial Nerves

Medulla Oblongata Part of: Brainstem Functions- Regulates rate and force of heartbeat. Adjusts base rhythm of breathing. Sensation of touch, pain, pressure, and vibration. Reflexes for: swallowing, vomiting, coughing, and sneezing. Regulates the diameter of blood vessels.	Pons Part of: Brainstem Functions- Sensory and descending motor tracts. Helps control breathing
Midbrain Part of: Brainstem Functions- Reflexes of eyes, head, and neck in response to visual stimuli. Startle reflex. Coordinate muscular movements Associated with Parkinson's Disease	Thalamus Part of: Diencephalon Functions- Aids in motor functions. Regulates Autonomic Nervous System (ANS) Maintaining consciousness Acquistion of knowledge (cognition)
Hypothalamus Part of: Diencephalon Functions- Control ANS Controls pituitary gland Controls body temperature Circadian rhythms Regulates emotions and behavioral patterns. Eating & Drinking	Pineal Gland Part of: Diencephalon Function- Produces Melatonin Melatonin promotes sleepiness *Tryptophan in turkey is converted to melatonin.
Limbic System The "Emotional Brain" Functions- Survival Food Fight or Flight Reproduction	Cerebellum Functions- Regulates posture and balance. Essential for all skilled motor activities, i.e. art, music, and sports.
Corpus Callosum *Fibrous band of white matter. Part of: Cerebrum Functions: Allows communication between the two hemispheres.	Cerebral Cortex Part of: Cerebrum Functions- Initiates movement. Deals with memory, emotions, intelligence, will, and judgement.

The cerebrum contains 4 lobes in each of its two hemispheres. The lobes and their functions are as follows:

1. Frontal Lobe-motor and emotions.
2. Temporal Lobe-tunes-auditory (sounds).
3. Parietal Lobe-pressure (touch) and palate (taste).
4. Occipetal Lobe-optics (vision).

Cranial Nerves

The brains has 12 cranial nerves within it as well. The following is a listing of the cranial nerves and their corresponding functions.

• I-Olfactory Nerve- Smell
• II-Optic Nerve-Vision
• III-Oculomotor Nerve-Muscle sense (proprioception), movement of the eyelid and eyeball, alteration of the lens for near vision, and constriction of the pupil.
• IV-Trochlear Nerve-Proprioception and movement of the eyeball.
• V-Trigeminal Nerve-Touch, pain, temperature, proprioception and chewing.
• VI-Abducens Nerve-Proprioception and movement of the eyeball.
• VII-Facial Nerve-Taste, proprioception, facial expressions, and secretion of tears and saliva.
• VIII-Vestibulocochlear Nerve-Equilibrium, adjust sensitivity of hair cells, hearing, modifies responses of hair cells.
• IX-Glossopharyngeal Nerve-Taste and somatic sensations, proprioception, monitors blood pressure, oxygen, and carbon dioxide levels, swallowing, and secretion of saliva.
• X-Vagus Nerve-Somatic sensations, monitors blood pressure, oxygen, and carbon dioxide levels, swallowing, coughing, voice production, smooth muscle control, slows heart rate, and secretion of digestive fluids.
• XI-Accessory Nerve-Proprioception, swallowing, and movement of the head and shoulders.
• XII-Hypoglossal Nerve-Proprioception, and movement of the tongue during speech and swallowing.

A few useful links:

This one has the sheep brain dissection for this class:

• www.delta.edu/dmknox/Systempages/web.brain/sheephuman/webbrain.html

This one has some pretty cool MRI pics of the brain to look at:

• http://www.med.harvard.edu/AANLIB/cases/caseM/case.html

These next two are great for helping to learn the cranial nerves:

• http://faculty.washington.edu/chudler/cranial.html
• http://www.gwc.maricopa.edu/class/bio201/cn/cranial.htm

This one shows saltatory conduction:

• http://www.brainviews.com/abFiles/AniSalt.htm