1 / 17

Chapter 9 Nervous System

Chapter 9 Nervous System. 9.10-9.13. 9.10. Types of Nerves. Types of Nerves. Nerve = bundles of axons Sensory nerves = conduct impulses to the brain or spinal cord Motor nerves = carry impulses to the muscles and glands Mixed nerves = include both sensory and motor fibers. 9.11.

sonja
Télécharger la présentation

Chapter 9 Nervous System

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. Chapter 9Nervous System 9.10-9.13

  2. 9.10 Types of Nerves

  3. Types of Nerves • Nerve = bundles of axons • Sensory nerves = conduct impulses to the brain or spinal cord • Motor nerves = carry impulses to the muscles and glands • Mixed nerves = include both sensory and motor fibers

  4. 9.11 Nerve Pathways

  5. Reflex Arcs • Reflex arcs = the simplest of nerve pathways with only a few neurons • Reflexes = a rapid, automatic, involuntary response to a stimulus

  6. Reflex Behavior • Control heart rate, breathing rate, blood pressure, and digestion • Carry out swallowing, sneezing, coughing, and vomiting

  7. Reflex Behavior • Patellar reflex = knee-jerk reflex • Only 2 neurons (sensory and motor) • Helps maintain upright posture • Withdrawal reflex = occurs when you touch a body part to something painful (like stepping on a tack) • Skin receptors  sensory nerves  interneuron  motor neuron  muscles contract • Other interneurons carry sensory impulses to the brain (makes you aware of the pain) • Limits tissue damage

  8. 9.12 Meninges

  9. Meninges • Meninges = membranes that cover the brain and spinal cordand offer protection • Three layers • Dura mater • Arachnoid mater • Pia mater

  10. Dura Mater • Outermost layer of the meninges • Tough, white, fibrous connective tissue • Many blood vessels and nerves • Forms periosteum in brain, but is not connected to the vertebrae in the spinal cord (epidural space)

  11. Arachnoid Mater • Thin, weblike membrane without blood vessels • Between the dura and pia mater • Below is the subarachnoid space with clear, watery cerebrospinal fluid (CSF)

  12. Pia Mater • Very thin and contains many nerves and blood vessels • Nourishes the underlying cells of the brain and spinal cord • Hugs the surface of the organs

  13. 9.13 Spinal Cord

  14. Structure of the Spinal Cord • Spinal cord= slender nerve column passing downward from the brain into the vertebral canal • Begins at the foramen magnum • Tapers to a point and terminates in the lumbar region • Spinal nerves = nerves that arise from the spinal cord and connect it to various body parts (31 pairs)

  15. Structure of the Spinal Cord • Cervical enlargement – supplies nerves to the upper limbs • Lumbar enlargement – gives off nerves to the lower limbs • Central canal – contains cerebrospinal fluid • Nerve tracts – myelinated nerve fibers that comprise major nerve pathways

  16. Structure of the Spinal Cord

  17. Functions of the Spinal Cord • Two major functions • Conduct nerve impulses • Center for spinal reflexes • Ascending tracts = carry sensory info to the brain • Descending tracts = conduct motor impulses from the brain to muscles and glands

More Related