Lecture 29: Brains Structures and Functions (Part 2)

Question 1

diencephalon: thalamus

Answer 1

• location: superior to the brain stem between the cerebral cortex and the midbrain
• function:
  1. relay station for sensory and motor information
  2. forms walls of third ventricle
  3. crude interpretation of touch, temperature, pain, and pressure
• organized into 7 groups of nuclei

Question 2

cerebellum

Answer 2

• location: posterior to brainstem
• function:
  1. receives input from proprioceptors in muscles and tendons regarding movement
  2. receives inputs from visual and equilibrium receptors and sends input to motor cortex to aid in regulation of pressure and balance

Question 3

brain stem: pons

Answer 3

• location: superior to medulla, inferior to midbrain
• function:
  1. bridge between pons, cerebellum, and higher brain centers in the cerebral cortex
  2. respiratory control (apneustic area: controls depth of breathing, pneumotaxic area: controls rate of breathing)
  3. coordinate voluntary motor output (pontine nuclei of pons… gray matter centers connecting the cerebral cortex and cerebellum)
• nuclei and tracts

Question 4

limbic system

Answer 4

• location: encircles upper part of brain stem and corpus callosum, also the inner border of the cerebrum and floor of the diencephalon (composed of parts of the cerebral cortex, diencephalon, and midbrain)
• function: connects motivation to action, emotional brain (pleasure, pain, docility, affection, fear, and anger), memory
  1. cingulate gyrus: emotion
  2. hippocampus: learning and memory
  3. amygdala: emotion and memory

Question 5

diencephalon: hypothalamus

Answer 5

• location: inferior to thalamus
• function:
  1. controls and integrates the activity of the pituitary gland and ANS (homeostasis!!)
  2. regulates body temp, eating and drinking behavior, other biological drives
  3. main control center over visceral functions
  4. receives info from cerebrum, brainstem, and spinal cord
  5. regulates emotions (pleasure, pain, aggression)
  6. regulates diurnal rhythms with help from the pineal gland (melatonin)
• pituitary gland: anterior synthesizes and releases 6 hormones, posterior releases 2 hormones

Question 6

diencephalon: epithalamus

Answer 6

• location: superior and posterior to the thalamus
• function:
  1. pineal gland (melatonin): contributes to regulation of biological clock
  2. habenular nuclei: emotional responses to odors

Question 7

brain stem: medulla oblongata

Answer 7

• location: inferior to midbrain and pons
• function:
  1. connects brain to spinal cord
  2. controls heart rate and force, blood pressure (cardiovascular center)
  3. controls respiratory rhythmicity
  4. controls vegetative functions (swallowing, coughing, sneezing, vomiting)
• involves all ascending and descending nerve tracts from the brain, axons cross over from one side of the brain stem to the other
• nuclei and tracts

Question 8

brain stem: midbrain (mesencephalon)

Answer 8

• location: superior to pons and medulla, between pons and diencephalon
• function:
  1. reflexes for certain visual activities and movements of the head and trunk in response to visual stimuli (superior colliculi)
  2. part of the auditory pathway and startle reflex (inferior colliculi)
  3. controls subconscious muscle activities (neurons that release dopamine extend from the darkly pigmented nuclei, substantia nigra, of midbrain)
  4. controls voluntary movement of limbs (red nucleus)
• nuclei and tracts