SCIENCE MODULE 1: QUARTER 3

• What are the major divisions and parts of the Nervous System?

  Central Nervous System (CNS) and Peripheral Nervous System (PNS)
• Central Nervous System (CNS)


  this serves as the main processing center for the entire nervous system
• What are the 2 main components of the Central Nervous System (CNS)?

  Brain and Spinal Cord
• Brain


  an organ located within the skull that functions as organizer and distributor of information for the body.
• Spinal Cord


  serves as a channel for signals between the brain and the rest of the body, and controls simple musculoskeletal reflexes without input from the brain
• What are the 3 main parts of the Brain?

  cerebrum, cerebellum, brain stem
• Cerebrum


  large, upper part of the brain that controls activity and thought
• Cerebellum


  the part under the cerebrum that controls posture, balance and coordination
• Brain Stem


  the part that connects the brain to the spinal cord and controls automatic functions such as breathing, digestion, heart rate and blood pressure
• Peripheral nervous System (PNS)


  this connects the central nervous system to the organs and limbs.
• What are the 2 main divisions of Peripheral Nervous System (PNS)?

  Somatic Nervous System and Autonomic Nervous System
• Somatic Nervous System


  this system associated the central nervous system to the organs and limbs.
• Autonomic Nervous System


  this system is associated with the INVOLUNTARY control of body movements.
• What is the 2 subdivisions of Somatic Nervous System?

  Spinal Nerves and Cranial Nerves
• Spinal Nerves


  The nerves that carry motor and sensory signals between the spinal cord and the body.
• Cranial Nerves


  the nerve fibers that carry information into and out of the brain system
• What are 2 subdivisions of Autonomic Nervous System?

  Sympathetic and Parasympathetic
• Sympathetic


  it is activated when the body is in a dynamic role or stress (e.g. increased heart rate and breathing, dilation of pupil, sweating, etc.)
• Parasympathetic


  it maintains the body functions and restores the body to normal or relaxed mode.
• Nerve Cells


  it is the basic unit of the nervous system
• Neurons


  nerve cells are called....
• Brain and Spinal Cord


  There are billions of neurons in the body. some exist alone. others are joined together to form organs like...
• Dendrites and Axons


  a neuron has a cell body containing the nucleus. projecting out from the cell body are root-like structures called...
• Dendrites


  carry impulses toward the cell body
• Axons


  carry impulses away from the cell body. this pass impulses to the dendrites of other neurons or cell body of muscle cells.
• How long can a single dendrite be?

  one meter long
• Nerves


  axons can be grouped together into cable-like bundles called...
• Neurons


  are cells with the special ability to carry signals or impulses. thoughts, emotions, learning and many body functions are carried by nerve impulses in the....
• Nerve Impulse


  is a combination of an electrical charge and a chemical reaction. This is not a flow of electricity, but an electrochemical signal moving along a neuron.
• Neurotransmitter


  when a nerve impulse comes to the end of an axon, it produces the chemical called...
• Synapse


  A junction where information is transmitted from one neuron to the next. the chemical crosses the space between neurons and stimulates the nerve impulse to start in the next dendrite.
• Stimulus


  is any factor in the environment that may trigger a nerve impulse
• Response


  a reaction to a stimulus
• Does messages travel in both directions?

  No
• Reaction Time


  is the length of time between application of a stimulus and detection of a response
• Motor Neurons


  It is a kind of neurons that transmit impulses from the brain to muscles, glands or other neurons in the Peripheral Nervous System (PNS)
• Sensory Neurons


  Neurons that transmits impulses from sensory nerves (receptor cells) to the Central Nervous System (CNS)
• Endocrine System


  A system that controls and regulates body processes. Generally, the endocrine system is in control of the mechanisms in the body that slowly take place, such as cell growth. Rapid processes, such as body movement and breathing, are controlled by the nervous system
• Endocrine System


  this system is composed of glands that secrete different types of hormones that affect almost every cell, organ, and function of our body. It is essential in regulating growth and development, metabolism, as well as reproductive processes and mood.
• Hormones


  chemical messengers that are manufactured by the endocrine glands, travel through the bloodstream, and affect other tissues.