The brain Flashcards
What makes up diencephalon?
Thalamus
Hypothalamus
What makes up brain stem?
Midbrain
Pons
Medulla
Cerebrum
Uppermost part of brain
2 hemispheres - left and right, split by the longitudinal fissure
Corpus callosum links L and R brain sides (these are the commisural fibres)
Right side of brain controls left side of body and vice Vera (usually)
Ascending and descending pathways cross in medial of brain stem
Association fibres- connect parts within same hemisphere of brain
Internal capsule- between thalamus and globus pallidus. All ascending and descending pathways go through here.
Cerebral white matter= internal capsule, association fibres and corpus callosum with commisural fibres
Grey matter = external part of cerebrum called cerebral cortex. Made of the cell bodies and white matter made of axons.
What are the parts of the grey matter?
BCSSPG
BASAL GANGLIA CAUDATE NUCLEUS SUBTHALAMIC NUCLEUS SUBSTANTIA NIGRA PUTAMEN GLOBUS PALLIDUS
What are lobes in the cerebrum?
Frontal lobe- with motor cortex
Parietal lobe- sensory cortex
Occipital lobe
Temporal lobe
FRONTAL LOBE
Produces movement - planning and execution in its pre motor and motor cortex
Brocas Area = Produces movement of speech and translates thought into speech
Issue with Broca’s area = expressive dysphasia , as cant express thoughts to words
Personality
Behaviour
Memory ability
Ability to Think, problem solve and plan ahead
Can have frontal lobectomy- for behaviour problems but causes other issue - eg, social or lacks personality
Pre motor area= Damage to here causes problems planning and initiation of movement
Apraxia means damage to pre motor area and they perform strange activities eg, toothbrush to brush their hair
Motor cortex= controls voluntary movement, sends the motor info down the internal capsule to spinal cord and out as peripheral nerves
Motor homunculus = a map showing which pars of brain affect which motor movements in different body parts.
PARIETAL LOBE
Just behind the frontal lobe
Front of parietal lobe has somatosensory cortex - makes sense of sensations from the body. Receives and processes sensory information.
Sensory receptor - to spinal cord- thalamus - sensory cortex
Issue to sensory cortex means we can’t interpret sensory information, no body or spatial awareness
Somatosensory Homunculus map
Right side of sensory cortex damaged = left side sensory deficits in body
Left side sensory cortex damaged = right side sensory deficits in body
Damage is: Loss of sensation, altered sensation like pins and needles or hyper sensation
TEMPORAL LOBE
Lateral sides of brain
Role in interpreting speech and sounds
Primary auditory centre in middle and wernickes area to left
Primary auditory centre interprets pitch and rhythm of sounds
Wernickes area: determines if sound is speech or music or noise
Makes sense of words being said
Translates words into thoughts
Memory of sounds and words
A damaged wernickes area = Receptive dysphasia, can’t understand what someone’s saying
Occipital lobe
Back of brain
Interprets visual input
Information through eyes, retina, optic nerve, thalamus then occipital lobe
The occipital lobe :
Interprets intensity of light or dark, shapes and movement of objects
Colour of something
Relates past visual experiences with recognition and evaluation
Brain stem
Midbrain , pons and medulla
In medulla- motor and sensory pathways cross over
Brain stem holds vital control centre = respiratory, cardiac, vasomotor, swallowing, gastric secretion and sweating
Brain stem is all unconscious thought
Holds vestibular nuclei - Aware of body in space and balance and coordination.
Nuclei of the cranial nerves (are peripheral)
Name the cranial nerves
On old Olympic towering tops a fin and German viewed some hops
Olfactory Optic Oculomotor Trochlear Trigeminal Abducens Facial nerve 7 Auditory nerve / vestibulocochlear Glossopharyngeal Vagus nerve 10 Spinal accessory Hypoglossal
Can cranial nerves regenerate ?
Yes
By wallerian regeneration
Diencephalon
Thalamus- principle relay station for sensory input to take it to sensory cortex
Interprets crude sensations
Hypothalamus- regulates homeostasis by acting on pituitary gland and autonomic nervous system eg, temperature, water etc.
Limbic system
Controls emotional response to situations and memories
If brain damage to limbic system = very emotional patient
CHAM structures:
Cingulate Gyrus
Hippocampus (memory of events, people and places but NOT MOVEMENTS)
Amygdala- controls emotions of fear, anger, sadness etc
Mammillary bodies
Link to sense of smell and taste and the memory of something
Patients may misinterpret memory and events and recall strange events
Cerebellum
Very base of brain and communicates with pons
Interaction of cerebellum with motor cortex produces coordinated movement and balance and good posture.
Damage to cerebellum causes poor balance, movements and coordination.
May get ataxia- no coordination, loss of balance, falling, stumbling etc
