Exam 1 Moved to the 31 of January

Thebrainmcgill Simple to complex Neurological level Intermediate level Midsagittal view

Slides 5, 6, 8, 9 Could be on test So be ready to label structures and their functions

Brainstem Cerebellum & Deep Structures Brainstem: Midbrain, Pons, Medulla Thalamus Cerebellum Basal Ganglia Limbic System

Nuclei Collection of neuronal somas in the deeper brain structures Nerves Contain the axons from the neuron cell bodies aka soma

Nuclei is a collection of neuronal cell bodies Nerve is a collection (fascicle) of neuronal axons

Brainstem Primitive Part of Brain –Midbrain aka mesencephalon –Pons metencephalon together with cerebellum –Medulla Oblongata myencephalon

MIDBRAIN Functions in visual and auditory orientation reflexes, maintaining posture and voluntary movements of body and face Contains nuclei for cranial nerves 3, oculomotor; 4, trochlear; 6, abducens a thoroughfare for axons entering and leaving brain.

PONS Central portion of brainstem Regulates respiration, thoroughfare for motor and sensory fibers, controls movement of face & jaw muscles, eye movement & sensation to face Contains nuclei for cranial nerves: 5, trigem; 7, facial Trigeminal, abducens, facial, vestibulocochlear nerves run through it

Medulla Oblongata Caudal portion of brainstem, leads to spinal cord Contains nuclei for CN 9-12 involved in speech (tongue & vocal cords), swallowing, move neck & shoulder muscles, salivation, taste Thoroughfare for afferent & efferent fibers

Motor Modulation Systems Cerebellum Basal Ganglia

CEREBELLUM derived from hindbrain but not part of brain stem. connected to pons and medulla by cerebellar peduncles that are made up of axons entering and leaving the cerebellum 4th ventricle separates it from brain stem.

Cerebellum Major functions –Coordinate muscle activity –Posture –Equilibrium –Spatial Reasoning

Function Motor control for muscle coordination and in planning complicated movements Cognitive tasks involved in learning and memory of motor task. Lesions to humans or animals shows that distinct areas of the cb are necessary for spatial reasoning, keeping muscle tone during voluntary movement or reflexes people can't walk in a coordinated smooth manner after cb lesion ie they appear to walk as if drunk

Cerebellar Lobes Rostral or anterior Caudal or posterior Vermis Flocculonodular Folia is a term used from gyri in cerebellar cortex that are smaller than in cerebral cortex

Deep Cerebellar Nuclei Emboliform Dentate Globose Fastigial Are main output neurons from cerebellum

Deep Brain Nuclei Diencephalon: processing sensory & motor information & endocrine role Basal Ganglia-Striatum: 3 forebrain nuclei involved in motor control Limbic System: Involved in regulating emotion, motivation & homeostasis

DIENCEPHALON Anterior to midbrain and forms the walls of the third ventricle. Consists of two parts, the thalamus and hypothalamus –Thalamus: processes sensory info & relays motor info –Hypothalamus: part of limbic system, controls pituitary

THALAMUS Subdividing into 6 nuclei Relay station for afferent incoming sensory information on the way to the appropriate cortical regions. Several nuclei in the thalamus receive visual information from the optic nerves Other nuclei receive auditory information and motor information.

HYPOTHALAMUS involved in maintaining homeostasis, controls body temperature, blood pressure, salt and water levels initiates and supresses eating, drinking Activates and inhibits pituitary gland, a neuroendocrine organ regulates autonomic function such as blood pressure & temperature involved in emotional responses such as changes in blood pressure/heart rate/respiration, blushing and sweating

BASAL GANGLIA Nuclei surrounding thalamus with common function –3 components putamen, globus pallidus, caudate nucleus aka striatum Substantia nigra Subthalamic nuclei

Deep Brain Nuclei involved in starting and stopping movement Disease to substantia nigra causes parkinson’s disease

Function Function in initiation and planning of voluntary movement and tone of antigravity muscles.

Limbic System Limbic means “border/edge” Function to –Regulate visceral motor function –Emotions, fear irritability depression aggresion –Memory –Olfaction—food aversions

Stop Here Slides have details that will not be included in the test. They will be covered during the 2 nd half of the course.