science test april 26

• Neurotransmitters


  Chemical messengers that transmit signals between neurons and other cells in the body

  
• Common Neurotransmitters and Their Functions

  • Norepinephrine: Linked to mood, memory, and stress
  • Serotonin: "Calming" chemical, mood modifier, linked to depression, appetite, sleep, memory, and decision-making
  • Dopamine: "Pleasure chemical" released when mammals receive a reward

  
• Norepinephrine and epinephrine


  • Very similar neurotransmitters and hormones, with norepinephrine having more of an effect on blood vessels and epinephrine having more of an effect on the heart
  • Both play a role in the body's fight-or-flight response to stress
• Fight, flight, or freeze response


  The body's natural reaction to a perceived harmful event, attack, or threat to survival
• Neurological disorders are primarily characterized by neuron loss
• Alzheimer's disease


  Affects brain function, memory, and behaviour, and is the most common cause of dementia

  
• Cerebral palsy


  Caused by abnormal/irregular brain development or damage to the developing brain in the parts that control movement, affecting a person's ability to control their muscles
• Multiple sclerosis


  An autoimmune disorder leading to demyelination of nerve cells and disruption of nerve impulses
• Types of stroke


  • Ischemic (caused by blockage of an artery)
  • Hemorrhagic (caused by bleeding)

  
• Anoxia

  Lack of oxygen
• Hypoxia


  Low oxygen
• Neurotransmitters


  Chemicals that transmit signals between neurons in the nervous system

  
• Common Neurotransmitters and Their Functions

  • Norepinephrine: a hormone linked to mood, memory, and stress
  • Serotonin: "calming" chemical, mood modifier, linked to depression, appetite, sleep, memory, and decision-making
  • Dopamine: "pleasure chemical" released when mammals receive a reward

  
• Fight, Flight, or Freeze Response


  Triggered by the release of neurotransmitters like norepinephrine and epinephrine
• Neurological Disorders are primarily characterized by neuron loss
• Alzheimer's disease


  Affects brain function, memory, and behaviour. It is the most common cause of dementia.

  
• Cerebral palsy


  Caused by abnormal/irregular brain development or damage to the developing brain in the parts of the brain that control movement. It affects a person's ability to control their muscles.
• Multiple sclerosis


  An autoimmune disorder leading to demyelination of nerve cells and disruption of nerve impulses
• Ischemic stroke


  Caused by blockage of an artery, accounting for about 87% of all strokes

  
• Hemorrhagic stroke


  Caused by bleeding, accounting for about 13% of all strokes

  
• Anoxia


  Lack of oxygen
• Hypoxia


  Low oxygen
• Thrombotic stroke


  Caused by a blood clot (thrombus) blocking an artery to the brain
• Embolic stroke


  Caused by a blood clot (embolus) that forms elsewhere in the body and travels to the brain

  
• Bell's palsy


  A condition that causes sudden weakness in the muscles on one side of the face
• Amyotrophic lateral sclerosis (ALS)


  A fatal type of motor neuron disease characterized by progressive degeneration of nerve cells in the spinal cord and brain
• Hippocampus


  Embedded deep in the temporal lobe, with a major role in learning and memory
• The five basic human senses are sight, smell, hearing, taste, and touch

  
• Stimuli


  Changes in one's environment
• Receptor


  Groups of cells found on our sensory organs that detect changes in the environment
• Sensory organ


  The organs that make our senses possible; our eyes, ears, nose, tongue, and skin
• Taste buds


  The sensory receptors for taste, found in the grooves on the surface of the tongue

  
• Flavours detected by taste buds

  • Sweet
  • Salty
  • Sour
  • Bitter
  • Umami (savoury)

  
• Taste


  Flavour molecules dissolved in saliva stimulate the taste bud receptor cells, which transform the stimulus into a nerve signal transmitted to the brain

  
• In addition to the 5 flavours, the tongue can also perceive temperature, pressure, and pain

  
• Anosmia


  Partial or full loss of smell, can be temporary or permanent
• Olfaction


  Sense of smell
• Smell


  Air containing odour molecules passes into the nasal cavity, stimulating olfactory receptor cells which transmit nerve impulses to the olfactory bulb in the brain
• The olfactory bulb sends nerve impulses to the olfactory cortex, which decodes the smell
• Mucus membranes


  Membranes that line the nasal cavity and can become irritated or obstructed