255 nervous system - Two subdivisions of the nervous system...

Info icon This preview shows pages 1–4. Sign up to view the full content.

Two subdivisions of the nervous system o Central nervous system Brain Spinal cord o Peripheral Nervous system Cranial nerves Spinal nerves Ganglia 3 main functions of the nervous system o Collecting information o Processing and evaluating information o Responding to information 2 functional divisions of nervous system o Sensory nervous system o Motor nervous system Sensory nervous system o Afferent- Receives sensory information from receptors in PNS and transmits it to CNS o 2 subdivided systems Somatic sensory Voluntary (touch, pain, pressure, vibration) Visceral sensory Involuntary (impulses from viscera) Motor nervous system o Efferent- Send impulses from CNS to muscles and glands o 2 subdivided systems Somatic motor Voluntary o Impulses from the CNS that cause contraction of skeletal muscles Autonomic motor Involuntary o Impulses from CNS that regulate smooth and cardiac muscle and glands Cytology o Neurons (nerve cells) Electrically excitable cells that initiate, transmit, and receive nerve impulses o Glial cells Nonexcitable cells that support and protect neurons
Image of page 1

Info icon This preview has intentionally blurred sections. Sign up to view the full version.

Neurons o Basic structural unit of nervous system o Conduct nerve impulses from one part of the body to another part o Features High metabolic rate Extreme longevity Nonmitotic Neuron structure o Cell body Contains: Nucleus Nucleolus Mitochondria Ribosomes and ER o Dendrites Toward cell body Short processes o Axon Away from cell body to other cells Anaxonic: do not have axon Axon hillock: region where axon connects to cell body o Axon collaterals Side branches of main axon o Telodendria Fine terminal extensions at end of the axon and its collaterals o Synaptic knobs Expanded regions at tip of telodendria Aka synaptic bulb, axon terminals, or synaptic button Structural Classification of neurons o Unipolar Single short process that branches like a T o Bipolar 2 processes, one dendrite and one axon o Multipolar Many dendrites and single axon Most common Functional Classification of neurons o Sensory Afferent Impulses from sensory receptors to CNS o Motor Efferent
Image of page 2
From CNS to muscles or glands o Interneurons Facilitate communication between sensory and motor neurons Glial cells o Aka neuroglia o Found in CNS and PNS o Smaller than neurons and capable of mitosis o Physically protect and nourish neurons o More numerous than neurons Brain tumors more likely to be derived from glial cells than neurons o 4 types Astrocytes Ependymal Microglial cells Oligodendrocytes Astrocytes o Type of glial cell o Most abundant glial cell in CNS o Functions Maintain blood-brain barrier/regulate blood flow Regulate tissue fluid composition Form structural network Replace damaged neurons Assist neuronal development Ependymal o Ciliated cuboidal epithelial cells o
Image of page 3

Info icon This preview has intentionally blurred sections. Sign up to view the full version.

Image of page 4
This is the end of the preview. Sign up to access the rest of the document.
  • Spring '08
  • Staff
  • Human Anatomy, Gray matter, white matter, sensory information

{[ snackBarMessage ]}

What students are saying

  • Left Quote Icon

    As a current student on this bumpy collegiate pathway, I stumbled upon Course Hero, where I can find study resources for nearly all my courses, get online help from tutors 24/7, and even share my old projects, papers, and lecture notes with other students.

    Student Picture

    Kiran Temple University Fox School of Business ‘17, Course Hero Intern

  • Left Quote Icon

    I cannot even describe how much Course Hero helped me this summer. It’s truly become something I can always rely on and help me. In the end, I was not only able to survive summer classes, but I was able to thrive thanks to Course Hero.

    Student Picture

    Dana University of Pennsylvania ‘17, Course Hero Intern

  • Left Quote Icon

    The ability to access any university’s resources through Course Hero proved invaluable in my case. I was behind on Tulane coursework and actually used UCLA’s materials to help me move forward and get everything together on time.

    Student Picture

    Jill Tulane University ‘16, Course Hero Intern