1 / 32

The Nervous System

The Nervous System. Central Nervous System (CNS) Peripheral Nervous System (PNS). Do Now:. Get Your Clicker! Contract a K-W-L chart on loose-leaf List everything you already K now about the Nervous System in the K-column List everything you Want to know in W -column. Functions.

ariana-campbell
Download Presentation

The 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. The Nervous System Central Nervous System (CNS) Peripheral Nervous System (PNS)

  2. Do Now: • Get Your Clicker! • Contract a K-W-L chart on loose-leaf • List everything you already Know about the Nervous System in the K-column • List everything you Want to know in W-column

  3. Functions • Monitors internal and external environments • Integrates sensory information • Coordinates voluntary and involuntary responses of other organ systems • 2 subdivisions: • CNS – brain and spinal cord • Intelligence, memory, emotion • PNS – all other neural tissue • sensory, motor

  4. Receptors and Effectors • Receptors – receive sensory info • Afferent division – carries info from sensory receptors to the CNS • Efferent division – carries info from CNS to PNS effectors (muscles, glands, adipose) • Somatic Nervous System (SNS) • Controls skeletal muscles (voluntary) • Autonomic Nervous System (ANS) • Controls involuntary actions • Sympathetic Division (increase heart rate) • Parasympathetic Division (decreases heart rate)

  5. Classwork: • Construct a flow chart detailing the direction in which information flows in the nervous system

  6. The sensory part of the PNS is... • Somatic division • Sympathetic division • Parasympathetic • Afferent division • Efferent division • Control center

  7. The fight or flight response is the... • Somatic division • Sympathetic division • Parasympathetic division • Afferent division • Efferent division • Control Center

  8. A change in ambient temperature would be detected by • Somatic division • Sympathetic division • Afferent division • Efferent division • Control Center

  9. Label Neuron • Read the functions to determine the structure of a typical neuron

  10. Neurons • Communicate w/other neurons • Soma-Cell body • Dendrites - receive info • Axon- sends signal to synaptic terminals (terminal buds) • Synapse – site of neural communication (gap) • Myelin – fatty insulation • Node of Ranvier – exposed axon between myelin • 3 structural types: • Multipolar – multiple dendrites & single axon (motor neurons) • Unipolar – continues dendrites & axon, cell body lies to side (sensory neurons) • Bipolar – one dendrite and one axon w/cell body between them (special senses)

  11. Types of Neurons • 3 functional types • Sensory – afferent division • info about surrounding environment • position/movement skeletal muscles • digestive, resp, cardiovasc, urinary, reprod, taste, and pain • Motor – efferent division (response) • skeletal muscles • cardiac and smooth muscle, glands, adipose tissue • Interneurons • Brain and spinal cord - memory, planning, and learning

  12. Neuroglia • Regulate environment around neurons; can be phagocytes; actively divide • Functions in CNS: • maintains the blood-brain barrier • create myelin (lipid) to coat axon • Nodes – gaps between myelinated sections • Internodes – areas covered in myelin • Phagocytic cells • Secrete cerebrospinal fluid (CSF)

  13. The most common type of neuron is • multipolar • bipolar • unipolar

  14. The part of the neuron that has receptor proteins on its surface is • Dendrites • soma • axon • Myelin sheath

  15. The part of the neuron that increases the speed of transmission is the • Dendrites • soma • axon • Myelin sheath

  16. Complete Action Potential POGIL • Remember: • Discuss each question and answer with your group • Use the information from the models to support your responses • You may use any resources to assist you

  17. Membrane Potential • Cells are polarized (measured in volts) • Resting potential of neuron -70mV • Remains stable due to Na+/K+ Pumps Leak channels – always open (K+ diffuses out) K+ Proteins- Net - charge Na+ Cl- Gated channels – open/closed under specific circumstance

  18. Changes in Membrane Potential • Depolarization • Stimulus opens Na+ gated channels • increase +charge of cell towards 0mV • Action Potentials • Affects entire surface of cell membrane • (+) feedback as nerve impulse continues • Hyperpolarization • Stimulus opens K+ gated channels • Increases –charge (from -70mV to -80mV) • Restores resting potential

  19. Action Potential: All or Nothing Principal • Only skeletal muscle fibers and neuron axons have excitable membranes • Graded potential increases pressure until sufficient enough to reach action potential • Resting potential (-70mV) • Reaches Threshold (-60mV) • Refractory Period – cell cannot respond to stimulation • Depolarization • Repolarization • Continuous Propagation • chain rxn until reaches cell memb • Unmyleinated – 1m/s (2mph) • Salatory Propagation • Myelinated (blocks flow of ions except at nodes) • Action potential jumps from node to node • 18-40m/s (30-300mph)

  20. Neural Communication • Nerve impulse – info moving in the form of action potentials along axons • At end of axon the action potential transfers to another neuron or effector cell by release of neurotransmitters from synaptic terminal (only occur in 1 direction) • Activity of neuron depends on balance between: • Excitatory neurotransmitters - depolorization • ACh & Norepinephrine • Inhibitory neurotransmitters -hyperpolarization • Dopamine, Seratonin, GABA

  21. An excitatory neurotransmitter • Increases electrical impulse • Causes the release of more neurotransmitters • Is released in a synaptic cleft • All of the above

  22. The resting membrane potential inside a neuron is • 0mV • 30mV • -60mV • -70mV

  23. After stimulus, the rush of sodium ions into the cell is called • depolarization • repolarization • hyperpolarization

  24. The action potential is propagated by • More Na+ rushing into the cell • K+ leaving the cell • Neurotransmitters binding to dendrite • Vesicles release neurotransmitters

  25. The cell’s charge at the peak depolarization is • 0mV • 30mV • -60mV • -70mV

  26. During repolarization • The resting potential is restored • K+ diffuse out of cell • The cell membrane becomes negatively charged again • All of the above

  27. Once the action potential reaches the axon terminal, the signal will be carried to the next neuron by • Na+ ions • Neurotransmitters • K+ ions • All of the above

  28. If an excitatory neurotransmitter binds to neuron number one, how will that affect the number of neurotransmitter released? • more • less • No effect at all

  29. 0 of 30 If previous neuron releases GABA, an inhibitory neurotransmitter, how will that affect neuron #2 • Increase electrical stimulus • Decrease electrical stimulus • Increase neurotransmitters released • decreased neurotransmitters released • 1&3 • 2&4

  30. Reflexes • Reflex – involuntary response to stimulus w/o requiring the brain • Reflex arc- sensory neuron Interneuron motor neuron (opposes initial stimulus) • Ex. Knee jerk reflex • Babinski reflex (infants only) • Stroke sole of foot  toes fan out • Plantar reflex (adults only) • Stroke sole of foot toes curl • Signals sent to brain by interneurons allow for control • Ex. Toilet training, gag, blink

  31. Testing reflexes activity

More Related