The Brain and Cranial Nerves Pg Three Main Regions of the Brain. Forebrain

Transcription

1 The Brain and Cranial Nerves Pg. 129 Three Main Regions of the Brain Forebrain Cerbral hemispheres Diencephalon Midbrain Brain stem Hindbrain Pons Cerebellum Medulla oblongata Interprets sensory inputs Controls voluntary and skilled muscle Functions in intellectual and emotional processing Forebrain 1

2 Grey Matter Cell bodies of neurons White Matter Fiber Tracts of neurons Gyrus Elevated Ridges Ex. Precentral Gyrus Primary Motor Area Sulcus Shallow Grooves Fissures Deep Groves Longitudinal Fissure Separates Hemispheres FRONTAL LOBE : Thinking Planning Personality Emotions TEMPORAL LOBE : Understanding speech Memory Hearing PARIETAL LOBE : Face Movements Drawing Feeling and touch OCCIPITAL LOBE : Vision Frontal Lobe Precentral Gyrus Primary Motor Area Learned Motor Skills Sense of Smell Prefrontal Cortex intellect, complex learning, recall, personality 2

3 Parietal Lobe Primary Somatosensory Cortex, receives input from sensory inputs Integrate different sensory inputs (temp., pressure, etc) Perception Taste Temporal Lobe Conscious Awareness of balance Auditory Language areas- Wernicke s Occipital Lobe Visual association area Primary Visual Cortex 3

4 Many similar functions in both cerebral hemispheres motor and sensory areas However, each hemisphere is a specialist Left Hemisphere Language brain Language and Speech skills Right Hemisphere Abstract, conceptual or spatial processes Artistic or creative pursuits Additional features to Identify: Corpus Callosum Connects two hemispheres of cerebral cortex Fornix Involved in smell Septum pellucidum Separates lateral ventricles of cerebral hemisphere Diencephalon Most superior portion of the Brain Stem Be able to Identify: Olfactory Bulbs and Tract Optic Nerves & Chiasma Pituitary Gland Hypothalmus 4

5 Diencephalon Thalmus Memory processing Senory impulse to cerebral cortex for processing Hypothalmus intergrates involuntary nervous system Regulates body temperature, food intake, water balance, thirst and biological rhythms Regulates hormones Midbrain (Brainstem) Functions in conducting pathways between higher and lower brain centers Cerebellum Composed of Two Hemisphere Connected by Vermis Composed of Grey & White matter Involved in unconscious coordination of skeletal muscle Provides instruction to cerebral motor cortex that aid in control of balance & equilibrium 5

6 Cerebellum Be able to identify: Vermis Arbor Vitae Tree of Life White Matter Coropora quadrigemina Involved in visual and auditory relfexes Meninges Covers and protects Brain 3 layers: Dura Mater Composed of 2 layers Arachnoid Mater Pia mater Meningitis Inflammation of meninges If spreads to neural tissue may cause encephalitis Diagnosed by taking sample of Cerebrospinal Fluid 6

7 Ventricles Circulate cerebrospinal fluid Provides cushion to brain and spinal chord Reduces brainweight by 97% prevents crushing under its own weight 4 total: Lateral Third Cerbral Aqueduct Fourth Now we look at Brains! Cranial Nerves 12 total Know their name and number Know their functions On Occasion Our Trusty Truck Acts Funny, Very Good Vehicle AnyHow 7

8 3 Purely Sensory I. Olfactory Sense of Smell 3 Purely Sensory I. Olfactory II. Optic Sense of Sight 3 Purely Sensory I. Olfactory II. Optic VIII. Vestibulocochlear Sense of Hearing 8

9 4 Associated with the Eye II. Optic III. Oculomotor IV. Trochlear VI. Abducens And the rest Major Sensory nerve of face And the rest VII. Facial Motor fibers to muscles of facial expression Sensory from anterior portion of tongue 9

10 And the rest VII. Facial IX. Glossopharyngeal Sensroy fibers to pharynx, tonsils, and posterior tongue Pharyngeal muscles And the rest VII. Facial IX. Glossopharyngeal X. Vagus Motor fibers for heart and smooth muscles of abdomen And the rest VII. Facial IX. Glossopharyngeal X. Vagus XI. Accessory Muscles associated with chewing 10

11 And the rest VII. Facial IX. Glossopharyngeal X. Vagus XI. Accessory XII. Hypoglossal Motor fibers to muscles of tongue Now we dissect sheep brains!! 11