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BIO 210 CHAPTER 13 The Central Nervous System SUPPLEMENT 2. PowerPoint by John McGill Supplemental Notes by Beth Wyatt. CEREBELLUM. Second Largest Division of the Brain Lies Below the Posterior Portion of the Cerebrum. CEREBELLUM. Second Largest Division of the Brain
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BIO 210 CHAPTER 13 The Central Nervous System SUPPLEMENT 2 PowerPoint by John McGill Supplemental Notes by Beth Wyatt
CEREBELLUM • Second Largest Division of the Brain • Lies Below the Posterior Portion of the Cerebrum
CEREBELLUM • Second Largest Division of the Brain • Lies Below the Posterior Portion of the Cerebrum
CEREBELLUM: Transverse Fissure OCCIPITAL LOBE • Horizontal Groove that Separates the Cerebrum from the Cerebellum CEREBELLUM
CEREBELLUM: CEREBELLAR HEMISPHERES • The 2 Halves of the Cerebellum that are Joined
CEREBELLUM: VERMIS • The Central Portion of the Cerebellum • Joins the 2 Cerebellar Hemispheres
A- sagittal fissure B - central sulcus C - frontal lobe D - parietal lobe E - occipital lobe F - temporal lobe G - cerebellum H - vermis I - medulla Sheep Brain
CEREBELLUM: Convolutions • Folds/ridges
CEREBELLUM: SULCI • Grooves
CEREBELLUM: Gray & White Matter • Arbor Vitae: Tree of Life • Centrally Located White Matter of Cerebellum
ARBOR VITAEhttp://www.vh.org/Providers/Textbooks/BrainAnatomy/Ch3Text/Section05.html
CEREBELLUM: Gray & White Matter • Cerebellar Cortex • Peripherally Located Gray Matter
Sheep Brain • 1. Arbor vitae (of cerebellum) • 2. Corpus callosum • 3. Fornix • 4. Optic chiasma • 5. Hypothalamus • 6. Mammillary body • 7. Lateral ventricle • 8. Thalamus • 9. Pineal body • 10. Tectum • 11. Cerebral aqueduct • 12. Pons • 13. Medulla oblongata • 14. Spinal cord • 15. Anterior commissure • 16. Corpora quadrigemina
CEREBELLUM: Peduncles • CEREBELLAR PEDUNCLES • INFERIOR, MIDDLE, SUPERIOR • Tracts that Connect Cerebellum to Other Parts of CNS (Primarily to Brainstem)
FUNCTIONS of the CEREBELLUM • All Functions of Cerebellum Involve Skeletal Muscles • SKILLED MOVEMENTS • (WITH CEREBRAL CORTEX) • Nerve Impulses from the Cerebellum Added to Nerve Impulses from the Cerebral Cortex Produce Movements (Skeletal Muscles) That are Co-ordinated and Precise • EQUILIBRIUM • Cerebellum Works with the Inner Ear and Skeletal Muscles to Help Maintain Balance • POSTURE • Cerebellum Controls Tonic Contractions
DIENCEPHALON • Between Brain • 3 MAJOR STRUCTURES • THALAMUS • HYPOTHALAMUS • PINEAL BODY
DIENCEPHALON: THALAMUS • Gray Matter Shaped Like a Dumb-bell Weight
DIENCEPHALON: HYPOTHALAMUS • Gray Matter Below Thalamus • Boundaries: • Anterior Portion: Optic Chiasma • Middle Portion: Infundibulum • Posterior Portion: Mamillary Bodies
Sheep HYPOTHALAMUS (#9) Optic Chiasma Mammilary Body Pituitary Gland
PINEAL BODY • Pine-cone Shaped Structure Located Above the Corpora Quadrigemina
Functions of the Diencephalon • THALAMUS • SENSATIONS (TWO PART MECHANISM) • SERVES AS A MAJOR RELAY STATION FOR SENSORY IMPULSES HEADED TO THE CEREBRAL CORTEX • PRODUCES CRUDE AWARENESS OF SOME GENERAL SENSATIONS
Functions of the Diencephalon: Thalamus • SENSATIONS: MAJOR RELAY STATION FOR SENSORY IMPULSES HEADED TO THE CEREBRAL CORTEX • Impulses That Will Eventually Reach the Cerebral Cortex and be Interpreted as Sensations* are First Relayed Through the Thalamus (Thalamus is the "Gateway to the Cerebral Cortex") • * All Sensations Except for Possibly Olfactory
Functions of the Diencephalon: Thalamus • PRODUCES CRUDE AWARENESS OF SOME GENERAL SENSATIONS • Crude Awareness: Not Precise/Fine Tuned • Cerebral Cortex Interprets Sensations; However, the Thalamus can Interpret SomeGeneralSensations, but Only on a Crude Level
Functions of the Diencephalon continued… • ASSOCIATION OF SENSATIONS WITH EMOTIONS • Thalamus Allows Us to Link Sensations (i.e., Taste) with Emotions (i.e., Unpleasantness) • AROUSAL (ALERTING MECHANISM) • Thalamus (as Well as Many Other Areas of the Brain) is Involved in Keeping Us Awake and Alert (Consciousness) • COMPLEX REFLEX MOVEMENTS • The Thalamus is Involved in Some Reflexes
HYPOTHALAMUS • REGULATES/CO‑ORDINATES ANS • There are Neuron Connections Between the Hypothalamus and the ANS • LINKS "PSYCHE" AND "SOMA" • Psyche: Mind/Awareness; Associated with the Cerebral Cortex • Soma: Body/Effectors; Associated with the ANS and the Somatic NS • Helps to Explain Psychosomatic Illness (Emotions can Lead to Changed Body Functions)
HYPOTHALAMUS controls PITUITARY GLAND • LINKS NERVOUS AND ENDOCRINE SYSTEMS (CONTROLS PITUITARY GLAND) • DIRECTLY: SYNTHESIZES POSTERIOR PITUITARY GLAND HORMONES (WATER BALANCE) • INDIRECTLY: REGULATES HORMONE SECRETION BY ANTERIOR PITUITARY GLAND (RELEASING HORMONES)
HYPOTHALAMUS & Posterior Pituitary Gland • DIRECTLY: SYNTHESIZES POSTERIOR PITUITARY GLAND HORMONES (WATER BALANCE) • The Hypothalamus ActuallyBuildstheHormonesofthe PPG; PPG Just Stores and Releases Them
HYPOTHALAMUS & Anterior Pituitary Gland • INDIRECTLY: REGULATES HORMONE SECRETION BY ANTERIOR PITUITARY GLAND (RELEASING HORMONES) • The APG Builds Its Own Hormones; However, Those Hormones Aren't Released Until the Hypothalamus "Says" They can be Released • Mouse pituitary: http://eulep.pdn.cam.ac.uk/Necropsy_of_the_Mouse/index.php?file=Chapter_6.html#fig23
RELEASING HORMONE PATHWAYS • The Way the Hypothalamus "Says" These Hormones can be Released is Through Releasing Hormones • i.e., Hypothalamus ‑‑‑‑‑> Releasing Hormones ‑‑‑‑‑> APG ‑‑‑‑‑> Release of APG Hormones
HYPOTHALAMUS: Overall Functions • AROUSAL (ALERTING) MECHANISM • REGULATES APPETITE AND FOOD INTAKE • REGULATION OF BODY TEMPERATURE
HYPOTHALAMUS: Alertness • AROUSAL (ALERTING) MECHANISM • The Hypothalamus is Also Involved in This Mechanism
HYPOTHALAMUS: Appetite • REGULATES APPETITE AND FOOD INTAKE • The Hypothalamus Contains Both Appetite and Satiety Centers (Clusters of Neurons) • When the Appetite Center is Stimulated, One Feels Hungry, When the Satiety is Stimulated, One Feels Full
HYPOTHALAMUS: Body Temperature • REGULATION OF BODY TEMPERATURE • The Hypothalamus Contains the Human Thermostat
PINEAL BODY • REGULATES BIOLOGICAL CLOCK • Individual's Unique Patterns of Eating and Sleeping; • Also Includes Cycles That Occur in the Female Reproductive System • SECRETES HORMONES (MELATONIN) • For This Reason, is Also Known as the Pineal Gland • Secretes Melatonin