Intro to the nervous system

• What is the major function of the nervous system?

  It is the major controlling, regulatory, and communicating system in the body.
• How do specialized cells in the nervous system function?

  They deliver information about the internal and external environment to the central processing center (CNS).
• What does the nervous system do with the information it gathers?

  It integrates information and sends out instructions for appropriate interaction with the environment.
• What is the center of all mental activity in the nervous system?

  The central nervous system (CNS).
• What are the functions of the central nervous system?

  It gathers and processes information, executes voluntary movements, and regulates internal environments.
• What are some examples of subconscious regulation by the CNS?

  Heart rate, blood pressure, digestion, metabolism, and reproductive function.
• How does the CNS contribute to emotional experiences?

  It allows us to experience emotions.
• What higher cognitive processes does the CNS perform?

  Thought, reasoning, learning, and memory.
• What is the role of the peripheral nervous system (PNS)?

  It carries information between the CNS and body tissues.
• What are the two divisions of the PNS?

  Afferent division and efferent division.
• What does the afferent division of the PNS do?

  It carries information towards the CNS.
• What is the function of the efferent division of the PNS?

  It carries information away from the CNS.
• What does the somatic nervous system innervate?

  Skeletal muscle.
• What type of movements does the somatic nervous system control?

  Voluntary and some involuntary movements.
• What does the autonomic nervous system innervate?

  Cardiac muscle, smooth muscle, and glands.
• What are the two divisions of the autonomic nervous system?

  Sympathetic nervous system and parasympathetic nervous system.

  
• What is the function of the sympathetic nervous system?

  It is responsible for "fight or flight" responses.
• What is the function of the parasympathetic nervous system?

  It is responsible for "rest and digest" responses.
• What are neurons?

  Specialized cells that receive and transmit electrical impulses.

  
• How many neurons are there approximately in the human CNS?

  About 86 billion neurons.
• What are the main parts of a neuron?

  Cell body (soma), dendrites, axon, and synaptic terminals.

  
• What is the function of dendrites in a neuron?

  They receive signals from surrounding and other neurons.

  
• What is the axon of a neuron?

  A single elongated, tubular extension that conducts impulses away from the cell body.

  
• What are synaptic terminals also known as?

  Axon terminals or synaptic boutons.
• How long can axons range in length?

  From less than 1 mm to more than 1 m.
• What is a nerve fibre?

  The elongated projection of a neuron, usually the axon.

  
• What can nerve fibres be?

  Myelinated or unmyelinated.
• What are nerves composed of?

  Bundles of individual nerve fibres, blood vessels, and connective tissue.

  
• How do neurons communicate?

  By receiving and transmitting electrical impulses called action potentials.

  
• What does the frequency of action potentials encode?

  Information.
• What can inappropriate firing of neurons lead to?

  Pathological conditions such as epilepsy.
• What happens during synaptic neurotransmission?

  Action potentials travel down the axon to the synaptic terminal, passing the signal to the target cell.

  
• What types of target cells can neurons communicate with?

  Another neuron, a muscle cell, or a gland cell.
• What are sensory receptors?

  Specialized cells or structures that respond to specific stimuli and convert them into electrical signals.
• What are some examples of sensory receptors?

  Mechanoreceptors, thermoreceptors, chemoreceptors, and photoreceptors.
• What is the spinal reflex arc?

  The most basic form of integrated neural activity that involves a motor response to sensory input.

  
• What is the pathway of a spinal reflex arc?

  Peripheral sensory receptors → sensory neuron → integration center in the CNS → motor neuron → effector tissue.

  
• What are the classifications of neurons based on function?

  Afferent, efferent, sensory, motor, and interneurons.
• What do afferent neurons do?

  Transmit information towards the CNS.
• What do efferent neurons do?

  Transmit information away from the CNS.