the brain & nervous system Flashcards
anterior vs posterior
anterior = towards the nose end
posterior = towards the tail-end
dorsal vs ventral
dorsal = upper parts of the brain
ventral = lower parts of the brain
medial vs lateral
medial = center of the body
lateral = away from center
ipsilateral vs contralateral
ipsilateral = same side of the brain
contralateral = opposite side of the brain
superior vs inferior
superior = direction towards the top of the brain
inferior = direction towards the bottom of the brain
what is the cerebrum (forebrain)
- largest structure of the brain
- consists of the telencephalon
- contains the cerebral cortex and several subcortical structures
what is the cerebral cortex
the outer layer of the brain
- has 2 nearly symmetrical sides (L&R H)
- has many convolutions which consists of sulci, fissure and gyri
- each hemisphere is divided into 4 lobes: frontal, parietal, temporal & occipital
what is a sulcus (sulci)
a groove (inward) in the surface of the cerebral hemisphere (smaller than fissures)
lateral sulcus creates a boundary between frontal & temporal lobes
central sulcus creates a boundary between frontal & parietal lobes
what is a fissure
a major groove in the surface of the brain
central and lateral fissures divide each hemisphere into the lobes
what is a gyrus (gyri)
a convolution (bump) of the cortex of the cerebral hemisphere
separated by sulci or fissures
frontal lobe
- responsible for voluntary movement, expressive language & higher executive functions
- contains the prefrontal cortex & premotor cortex
- damage = personality changes, difficulty concentrating/planning & impulsivity
parietal lobe
- processes sensory info and responsible for sensory perception
- contains the somatosensory cortex
- damage = right-left confusion, difficulty with writing & math, inability to perceive objects normally
occipital lobes
- responsible for visual perception including color, form & motion
- contains the visual association cortex
- damage = difficulty locating objects & identifying colors
temporal lobe
- responsible for processing auditory info & encoding of memory
- contains auditory & visual association cortex
- damage = difficulty with identification of objects, learning & retaining info and impaired memory
cerebral commisures
connect the 2 hemisphere
corpus callosum, anterior commissure & posterior commissure
what is the limbic system
a collection of different brain structures associated with emotion, motivation, behavior & memory
includes the amygdala, hypothalamus, olfactory bulb, hippocampus & cingulate gyrus
what is the basal ganglia
a subcortical region associated with planning & directing movement
what are the 5 divisions of the brain
- telencephalon (cerebral hemispheres) - forebrain/cerebrum
- diencephalon - forebrain/brainstem
- mesencephalon (midbrain) - brainstem
- metencephalon - hindbrain/brainstem (except cerebellum)
- myelencephalon (medulla oblongata) - hindbrain/brainstem
telencephalon
the cerebral hemispheres
- largest division
- initiates voluntary movement, interprets sensory input & mediates complex cog processes
diencephalon
composed of the thalamus and hypothalamus & contains pituitary gland & optic chiasm
thalamus: a large, 2 lobed structure at the top of the brain stem
- contains sensory relay nuclei which receive signals from sensory receptors, processes them & send to appropriate area
hypothalamus: located just below thalamus
- imp for the regulation of several motivated behaviors
mesencephalon
divided into the tectum and tegmentum
tectum: composed of 2 pairs of bumps - the inferior colliculi (auditory) & the superior colliculi (visual-motor)
tegmentum: the division of the mesencephalon ventral to the tectum
metencephalon
contains the pons, cerebellum & reticular formation
pons: connects hindbrain with rest of the brain stem - responsible for sleep and arousal
cerebellum: an important sensorimotor structure = movement, balance & coordination
myelencephalon
most posterior division
composed of tracts carrying signals between the brain & body
reticular formation = a network of tiny nuclei that occupies the core of the brain stem and are involved in a variety of functions
central nervous system
- consists of brain & spinal cord (SC)
- communicates with the body through nerves attached to brain & SC
- contains neurons & glial cells
peripheral nervous system
-consists of nerves and most sensory organs
- divided into somatic and autonomic NS
sensory vs motor vs inter neurons
sensory (afferent) = gather sensory info from the environment & sends to brain
motor (efferent) = contract muscles to cause movement - info from brain to muscles
interneurons = located between sensory & motor neuron in the CNS
somatic NS
regulates conscious processes/voluntary control of the body
the body’s interaction w the environment
autonomic NS
regulates unconscious processes (e.g. heart rate & digestions)
regulates homeostasis
divided into sympathetic and parasympathetic
sympathetic NS
stimulates arousal & mobilizes energy - fight or flight
parasympathetic NS
inhibits arousal, stimulates relaxation & conserves energy
afferent vs efferent neurons
afferent = carry things to a central point
efferent = carry things away from a certain point
what are neurons
specialized cells that receive/process info & sends it to other cells
differ in structure depending on specialized function but there are 4 common structures: cell body, dendrites, axon & terminal buttons
dendrites
the branches of the neuron
- receive neural messages that are transmitted through the synapse
axon
the long slender tube often covered by a myelin sheath
- outer surface carries info from the cell body to the terminal buttons
terminal buttons / axon terminal
the little knobs at the ends of the axon branches
- secrete NTs when the AP reaches it
