The Vertebrate Brain

is regionally specialised
Forebrain
1. Diencephalon
  1. Hypothalamus
    1. regulates homeostasis and basic survival behaviors such as
      1. feeding
      2. fighting
      3. fleeing
      4. reproducing
    2. regulates the biological clock
      1. regulates cicardian rhythms such as the sleep/wake cycle
      2. most mammals have a pair of suprachiasmatic nuclei (SCN) in the hypothalamus which act as a biological clock
        Biological clocks generally require external cues to remain synchronised with environmental cycles
  2. Thalamus
    1. the main input centre for sensory information to the cerebrum
    2. the main output centre for motor information leaving the cerebrum
  3. Epithalamus
    1. pineal gland
      1. secretes melatonin
2. Cerebrum/telencephalon
  1. the structure which varies most across species
  2. has two hemispheres the right and the left
    1. each hemisphere consists of a cerebral cortex (grey matter) overlaying white matter and basal nuclei
  3. in humans the cerebral cortex is the largest and most complex part of the brain
    1. it controls voluntary movement and cognitive functions
  4. the basal nuclei are important centres for planning and learning movement sequences
    1. diseases of the basal ganlia include
      1. Parkinson's
      2. Huntington's
      3. Tourette syndrome
  5. lateralisation of cortical function
    1. corpus callosum
      1. a thick band of axons provides communication between the right and left hemispheres
      2. split brain occurs if corpus callosum is removed
    2. left hemisphere
      1. is more adept at language, maths, logic and processing of serial sequences
    3. right hemisphere
      1. is stronger at pattern recognition, nonverbal thinking and emotional processing
    4. the differences in hemisphere function are called lateralisation
  6. the right half of the cerebral cortex controls the left side fo the body and vice versa
  7. each side of the cerebral cortex has four lobes:
    1. frontal
    2. temporal
    3. occipital
    4. parietal
    5. each lobe contains primary sensory areas and association areas where information is integrated
The Brainstem
1. Hindbrain
  1. pons
    1. regulates the breathing centres in the meulla
  2. medulla oblongata
    1. contains centres that control several functions including
      1. breathing
      2. cardiovascular activity
      3. swallowing
      4. vomiting
      5. digestion
  3. cerebellum
    1. is important for
      1. movement coordination
      2. balance
      3. error checking during motor, perceptual and cognitive functions
    2. is involved in learning and remembering motor skills
    3. part of hind brain but not of Brainstem
2. Midbrain
  1. contains centres for receipt and integration of sensory information
3. coordinates and conducts information between brain centres
4. Arousal and sleep
  1. controled by both the cerebrum and the brainstem
  2. in the core of the brainstem there is a network of neurons called the reticular formation
    1. this regulates the amount and type of information that reaches the cerebral cortex and affects alertness
    2. the hormone melatonin is released by the pineal gland
      1. this plays a role in the sleep cycles of birds and mammals
  3. sleep is essential and may play and role in the consolidation of learning and memory
    1. dolphins sleep with one brain hemisphere at a time
      1. this means they are able to swim while they're "asleep"
the limbic system
1. where emotions are generated and experienced
  1. this takes place in other parts of the brain as well including various sensory areas
2. is a ring of structures around the brainstem inculding
  1. the amygdala
    1. located in the temporal lobe
      1. helps store an emotional experience as an emotional memory
  2. the hippocampus
  3. parts of the thalamus
the outermost layer of the cerebral cortex has a different arrangement in bird and mammals
1. in mammals the cerebral cortex has a convoluted surface called the neo cortex
  1. this was previously thought to be required for cognition
    1. cognition is the perception and reasoning that form knowledge
    2. however it has recently been shown that birds also demonstrate cognition even though they do not have a neocortex

Nächster

The Vertebrate Brain

Beschreibung

Zusammenfassung der Ressource

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