1 / 33

Lecture 11

Lecture 11. Nervous System Anatomy JPHubbard Hartnell College – Bio11. CNS Enclosed in cranial cavity & vertebral canal Covered by Meninges – 3 layers: Outer: _____________________ Folds create dural sinuses Middle: _____________________ Subarachnoid space contains: CSF

damon
Download Presentation

Lecture 11

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Lecture 11 Nervous System Anatomy JPHubbard Hartnell College – Bio11

  2. CNS • Enclosed in cranial cavity & vertebral canal • Covered by Meninges – 3 layers: • Outer: _____________________ • Folds create dural sinuses • Middle: _____________________ • Subarachnoid space contains: CSF • Inner: ______________________

  3. Spinal Cord Anatomy • Extends from brain to L1 • Tapered at caudal end – conus medullaris • Cauda equinae – extends into sacrum • Spinal Nerves: • Between each vertebrae • Include dorsal + ventral roots • Cross Section • White matter – towards outside • Gray matter – H pattern inside • Central canal – contains cerebrospinal fluid

  4. Functions of Spinal Cord • Tracts: Transmission of messages to and from brain • In white matter (myelinated nerves) • Ascending – to brain • Descending – motor information transmitted to spinal nerves • Serves as reflex center – by playing a part in reflex arcs – spinal reflexes

  5. Brain • Encased and protected in: skull/menenges/cerebrospinal fluid • Regions: Major Functions: • Cerebrum _______________ • Diencephalon _______________ • Cerebellum _______________ • Brain stem _______________ • 4 ventricles

  6. Cerebrum • Gyri and sulci form surface convolutions • Two hemispheres • Longitudinal fissure divides • Corpus callosum – connecting tracts • Five lobes • Frontal • Parietal • Temporal • Occipital • Insula • Cortex = gray matter

  7. Longitudinal fissure (green) Frontal lobe Central sulcus (yellow) precentral & postcentral gyrus Parietal lobe Parieto-occipital sulcus Occipital lobe Lateral sulcus (blue) Temporal lobe Insula Lobes and Fissures

  8. Functional Areas of Cerebrum • Motor areas • Basal Nuclei • Modify motor action • Sensory areas • Association areas

  9. Ventricles Hollow spaces within brain – 4 2 lateral ventricles Third ventricle: within diencephalon Interventricular foramen connects to lateral ventricles Forth ventricle: in brain stem Cerebral aqueduct = aqueduct of midbrain connects to 3rd ventricle Contain cerebrospinal fluid (CSF) Communicate with each other, central canal of spinal cord and with subarachnoid space CSF – produced at Choroid plexuses Cushions Removal of wastes

  10. Memory and the Limbic System • Learning – retention and utilization of past memories • Memory – ability to hold a thought or information • Short term – lack association • Long term – contextual development for facts • Semantic • Episodic • Skill association with motor activity

  11. Diencephalon • Maintenance of homeostatic function • Centers for control of • Body temp, heart rate/bp/thirst and electrolyte balance, glandular secretions … • Close ties with endocrine system • Regions: • Thalamus • hypothalamus

  12. Hypothalamus • Dozen or so nuclei in 4 major regions • mammillary bodies are relay station for olfactory reflexes;infundibulum suspends the pituitary gland • Major regulator of homeostasis • receives somatic and visceral input, taste, smell & hearing information; monitors osmotic pressure, temperature of blood

  13. Cerebellum • Acts as an integration/reflex center for sensory input from the eyes, ears, joints, and muscles that relates to body position. • Sends motor impulses to skeletal muscles that maintain posture and balance. • Communicates via cerebral peduncles (3 pairs)

  14. Cerebellum • 2 cerebellar hemispheres and vermis (central area) • Function • correct voluntary muscle contraction and posture based on sensory data from body about actual movements • sense of equilibrium

  15. Cerebellum • Transverse fissure between cerebellum & cerebrum • Cerebellar cortex (folia) & central nuclei are grey matter • Arbor vitae = tree of life = white matter

  16. Brain Stem • Medulla oblongata • Pons (‘bridge’) • Midbrain (= mesencephalon) • Functional: • Reticular formation • Reticular activating system (RAS) • Centers for control of vital functions • Cardiac center • Vasomotor center • Respiratory centers

  17. Peripheral Nervous System Afferent: Sensory Efferent: Motor Starts with cranial nerves: 12 pairs spinal nerves: 31 pairs

  18. Spinal nerves – 31 pairs – numbering: • 8 cervical • Numbers above corresponding vertebrae • C1 superior to Atlas • C2 superior to Axis … • C8 superior to 1st thoracic vert. • C1C4 cervical plexus • C4 T1  brachial plexus • 12 thoracic • T12  S4  lumbosacral plexus

  19. Spinal nerves begin as roots • Dorsal or posterior root is incoming sensory fibers • dorsal root ganglion (swelling) = cell bodies of sensory nerves • Ventral or anterior root carries outgoing motor fibers

  20. Output in Two Divisions of Peripheral Nervous System • Somatic: • What would this division control? • Autonomic System • 2 aspects: Fight or flight responses associated with: _____________________ Rest and repose – the SLUDD activities with: _____________________

  21. Neurotransmitters of the ANS • Acetylcholine: • All preganglonic fibers – both aspects • All Post ganglionic fibers in parasympathetic and few in the sympathetic aspect • = cholinergic fibers • Norepinephrine: • most sympathetic fibers • Dual innervation

More Related