nervous system: CNS brain Flashcards
parts
forebrain
midbrain
hindbrain
functional systems
forebrain parts
cerebrum
diencephalon
cerebrum
=right and left cerebral hemispheres
- lobes (named after overlying bones)
- frontal, temporal, parietal, occipital, insula (deep to temporal lobe)
cerebrum surface features
fissures
gyri
sulci
fissures
deep grooves
- longitudinal fissure (separates right and left hemispheres)
- transverse fissure (separates cerebellum and cerebrum)
- lateral fissure (separates temporal lobe from rest of cerebrum)
gyri
ridges
ex. postcentral gyrus in parietal lobe
precentral gyrus in frontal lobe
sulci
shallow grooves (separate gyri) ex. central sulcus - b/w frontal and parietal lobes
cerebrum has 3 layes
cerebral cortex
tracts
basal nuclei
cerebral cortex
2-4 mm thick, gray matter has functional areas: motor areas sensory areas association areas and others
motor areas
all in frontal lobe
- control skeletal muscle movement
- has three regions:
1. primary motor area (precentral gyrus)
2. premotor area
3. broca’s-language
sensory areas
a. general sensory area
b. vision
c. auditory and olfaction
d. taste and visceral sensation
general sensory area
pain, temp, touch, pressure
-postcentral gyrus in parietal lobe
vision
occipital lobe
auditory and olfaction
temporal lobe
taste and visceral sensation
(eg. full bladder)
- insula
association areas
recognize info from memories
-parietal, occipital, temporal lobes
others functional areas
memory in the temporal lobes
conscious intellect (personality, learning ideas, judgement etc)
-prefrontal cortex
tracts
white matter -types: association tracts commissural tracts projection tracts
association tracts
from gyrus to gyrus in same hemisphere
commissural tracts
from gyrus to gyrus in opposite hemispheres
eg. corpus callosum
projection tracts
run vertically (brain to spinal cord/ spinal cord to brain)
basal nuclei
paired masses of gray matter (w/in the white matter)
-involved in control of skeletal muscle movement
diencephalon
all gray matter
2 parts : thalamus and hypothalamus
thalamus
2 lobes connection by intermediate mass (bridge of gray matter across 3rd ventricle)
-relay station for most sensory impulses to cortex
hypothalamus
- inferior to thalamus, above pituitary
- major regulator of the internal environment (visceral control)
eg. blood pressure, heart rate
mid brain
-connects pons and diencephalon
-contains cerebral aqueduct
-anterior portion = cerebral peduncles (projection tracts)
-posterior portion = 4 nuclei = corpora quadrigemina
2 superior colliculi - visual reflexes
2 inferior colliculi - hearing and auditory reflexes
hindbrain contains
pons
medulla oblongata
cerebellum
pons
anterior to cerebellum
contains:
-tracts b/w brain and spinal cord and tracts to/from cerebellum
-pontine respiratory centres
medulla oblongata
inferior to pons
-ends at foramen magnum
-2 bulges called pyramids=large motor tracts ( = part of corticospinal tracts)
-just above spinal cord -> decussation of pyramids (tracts cross over)
(several non-vital centres - for swallowing, sneezing, vomiting)
medulla oblongata 3 vital centres (nuclei) in medulla
cardiac
vasomotor (blood vessels)
respiratory
brainstem is made up of
midbrain
pons
medulla
cerebellum
- posterior to pons and medulla
- has folds similar to gyri=folia (cortex (gray matter))
- arbor vitae (deep to cortex, anterior cerebellum) = white matter
- coordinates skeletal muscle contraction (posture and balance)
functional systems
- limbic system
- reticular formation
limbic system
- nuclei in cerebrum and diencephalon
- regulate emotion and emotional behaviours (laughing, crying, etc)
- contains areas involved in memory (memories evoke emotional responses)
reticular formation
-nuclei in brain
-cortex, thalamus and hypothalamus involved
(together form RAS- reticular activating system)
-regulates alertness and attention
(filters stimuli and only sends new/unusual signals to to other brain areas)
-sleep results when inhibited
-if damaged = coma
