biopsych

• What are the two main divisions of the nervous system?

  • Central Nervous System (CNS)
  • Peripheral Nervous System (PNS)
• What does the CNS consist of?

  The brain and the spinal cord
• What are the primary functions of the brain within the CNS?

  It performs all conscious and most unconscious processing.
• What is the role of the spinal cord in the CNS?

  It receives and transmits information and performs some reflex processing.
• What is the Peripheral Nervous System (PNS) and its two subdivisions?

  A body-wide network of messenger neurons with two subdivisions:

  • Autonomic Nervous System (ANS)
  • Somatic Nervous System (SNS)
• What is the function of sensory afferent neurons in the PNS?

  They take information to the CNS.
• What is the function of motor efferent neurons in the PNS?

  They take information away from the CNS.
• What controls actions of internal glands and is an involuntary system?

  The Autonomic Nervous System (ANS)
• What controls skeletal muscles and is a voluntary system?

  The Somatic Nervous System (SNS)
• What are the two branches of the ANS and their main effects?

  • Sympathetic system:
  • Increases bodily activities
  • Releases neuro adrenaline
  • Activates fight or flight response
  • Increases heart rate, breathing rate, sweating
  • Dilates pupils
  • Parasympathetic system:
  • Decreases bodily activities
  • Releases acetylcholine
  • Activates rest and digest response
  • Decreases heart rate, breathing rate, sweating
  • Constricts pupils
  • Maintains homeostasis
• What is homeostasis?

  The regulation of the internal environment by a balance between the sympathetic and parasympathetic systems.
• What is the endocrine system?

  A collection of glands around the body that regulate bodily functions, growth, and psychological factors by releasing chemical messengers called hormones into the blood.
• What are the roles of sensory relay and motor neurons in the reflex arc?

  • Sensory neuron:
  • Detects sensations (e.g., pain at sensory receptors)
  • Transmits action potential along myelinated axon
  • Converts electrical signal into chemical signal to cross the synapse
  • Relay neuron:
  • Receives chemical transmission
  • Forms new action potential in dendrites
  • Located in the spine
  • Sends a signal to the CNS
  • Immediately sends a signal along its axon to the motor neuron
  • Motor neuron:
  • Receives signal from the relay neuron via synaptic transmission
  • Passes the signal along its own myelinated axon
  • Stimulates an effector (e.g., muscle group)
  • Initiates movement away from the source of pain
• What is synaptic transmission and its process?

  • Synapse (axon terminal): Structure at the end of a neuron that allows neurons to communicate by passing on chemical signals.
  • Process of synaptic transmission:

  1. Action potential travels down the axon of the presynaptic neuron.
  2. Vesicles containing neurotransmitters merge with the cell membrane.
  3. Neurotransmitters are released into the synaptic cleft.
  4. Receptors on the postsynaptic neuron's dendritic membrane detect neurotransmitters.
  5. Chemistry within the postsynaptic neuron changes.
  6. If the charge passes a threshold, a new action potential forms.
  7. Neurotransmitters detach from receptors.
  8. Reuptake: Neurotransmitters return to the presynaptic cell via transport proteins.
• What is depolarization and hyperpolarization in relation to synaptic transmission?

  • Depolarization: Increase in the electrical charge inside a neuron, making it more likely to fire, caused by excitatory neurotransmitters.
  • Hyperpolarization: Decrease in the electrical charge inside a neuron, making it less likely to fire, caused by inhibitory neurotransmitters.
• What is summation in synaptic transmission?

  It is the combined effect of all inhibitory and excitatory influences, determining whether a new action potential forms.
• Why is information passed between pre- and postsynaptic neurons unidirectional?

  Because of the structure of the synapse, including the location of neurotransmitters and receptors.
• What is the fight or flight response?

  An evolutionary survival mechanism that prepares the body and mind for extreme action, such as fighting or escaping a threat.
• What triggers the fight or flight response?

  Detection of a stressor by the hypothalamus.
• What endocrine axis is activated during the fight or flight response?

  The Hypothalamic-Pituitary-Adrenal (HPA) axis.
• What hormone does the pituitary gland release during the fight or flight response?

  Adrenocorticotropic hormone (ACTH).
• What does the adrenal cortex release in response to ACTH?

  Cortisol.
• Which branch of the ANS is activated by the hypothalamus during the fight or flight response?

  The sympathetic branch.
• What part of the adrenal gland is triggered via the sympathetic adrenal medullary pathway?

  Adrenal medulla.
• Which hormone is released by the adrenal medulla during the fight or flight response?

  Adrenaline.
• What are the two main views on localization of function in the brain?

  • Localization of function: Specific functions are performed in distinct regions of the brain.
  • Holistic view: The brain acts as a whole to perform functions.
• Why is the fight or flight response considered maladaptive in the modern world?

  It is frequently triggered by stimuli that cannot be avoided, such as exams, resulting in acute and chronic stress and potentially stress-related illnesses.
• What does contralateral control refer to in the context of the brain?

  Each hemisphere controls the opposite side of the body, including motor and sensory pathways and vision of the contralateral visual field.
• What is hemispheric lateralization?

  Each hemisphere of the brain is specialized to perform different functions.
• In which hemisphere are language centers typically located?

  The left hemisphere.
• Which hemisphere is best suited for visuospatial tasks?

  The right hemisphere.
• Where are the motor, somatic sensory, visual, and auditory cortices located in the brain?

  On both sides of the brain.
• Which brain areas are exclusively located in the left hemisphere?

  Broca's area and Wernicke's area.
• What is the function of the motor cortex?

  Controls voluntary muscle motor movements across the body, contralaterally, located at the back of the frontal lobe, separated from the somatic sensory cortex by the central sulcus.
• What happens to muscle function if the motor cortex is damaged?

  Loss of muscle function or paralysis on the opposite side of the body.
• What is the function of the somatic sensory cortex?

  Receives sense impressions from around the body, contralaterally, located at the front of the parietal lobe, separated from the motor cortex by the central sulcus.
• What occurs if the somatic sensory cortex is damaged?

  Loss of sensation in the opposite side to the damage or neglect syndrome, where areas of the body are ignored.
• Where is Broca's area located and what is its function?

  Located in the left frontal lobe only, Broca's area is responsible for speech production. Damage results in motor aphasia, difficulty producing fluent speech.
• Where is Wernicke's area located and what is its function?

  Located in the left frontal lobe only, Wernicke's area is responsible for speech comprehension. Damage results in sensory aphasia, difficulty understanding speech.
• Where is the auditory cortex located and what does it do?

  Located in both hemispheres, the auditory cortex receives and processes sound information from the ears.