1 / 12

SBI4U The Importance of the Nervous System

SBI4U The Importance of the Nervous System. How does your brain control your body?. Importance of Nervous System. Your nervous system is active all the time It gets information about the depth of your breathing, pressure on your skin, temperature, light, odours etc.

davem
Télécharger la présentation

SBI4U The Importance of 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. SBI4U The Importance of the Nervous System How does your brain control your body?

  2. Importance of Nervous System • Your nervous system is active all the time • It gets information about the depth of your breathing, pressure on your skin, temperature, light, odours etc. • It controls muscle movements such as blinking, scratching your nose. Memory and language are functions of the nervous system.

  3. Vertebrate Nervous System • The nervous system (NS) has two main divisions: • Central Nervous System (CNS) • Peripheral Nervous System (PNS) • The CNS consists of the brain and the spinal cord and acts as a coordinating centre for incoming and outgoing information

  4. Nervous System (contd.) • The PNS consists of nerves that carry information between the organs of the body and the CNS • PNS is further subdivided into somatic nervous system and autonomic nervous system

  5. Nervous System (contd.) • Somatic NS controls the skeletal muscle, bones and skin. Somatic nerves can be either sensory nerves (relay info) or motor nerves (generate response). • The Autonomic NS controls the internal organs of the body. The two divisions of the ANS are : • Sympathetic nervous system (fight or flight) • Acetylcholine and norepinephrine • Parasympathetic nervous system (rest and digest) • Acetylcholine only

  6. What are their effects?

  7. So you should have….

  8. Nerve Cells • Two different types of cells are found in the Nervous System • Glial cells • Neurons • Glial cells are non-conducting cells that are used for structural support and metabolism of neurons • Neurons are the functional units of the nervous system

  9. Parts of a Neuron • Dendrite: projection of cytoplasm, carries impulses towards the cell body • Axon: extension of the cytoplasm that carries nerve impulses away from the cell body • Myelin Sheath: insulated covering over the axon • Axon Terminal: contains synapses, specialized structures where neurotransmitter chemicals are released in order to communicate with target neurons

  10. Types of Neurons • 3 groups: • Sensory neurons (aka afferent neurons): relay info from the environment to CNS. • Interneurons: link neurons, located in the brain and spinal cord usually; short length • Motor neurons (aka efferent neurons): relay information to the effectors which produce responses.

  11. Reflex Arc • Neural circuit through the spinal cord that provides a framework for a reflex action. • It begins with a receptor that relays the stimuli to spinal cord. Interneurons in the spinal cord receive information and relay it to motor neurons which activate the effector organs causing a response.

  12. Sequence of Events Stimulus causes signal in sensory receptors Message travels along sensory neuron Message reaches interneuron Message goes to brain Message travels in the motor neuron Message causes response (muscle to contract)

More Related