W5 - Brain Flashcards
Identify the major parts of the brain
3 parts: cerebrum, cerebellum and brainstem
Cerebrum
Largest and most superior part of brain
2 hemispheres: left and right split by a central fissure (longitudinal fissure)
Grey matter
Outermost layer of nerve cell tissue covered by grey matter (cerebral cortex)
Groups of grey matter (nuclei)
Critical role is information processing
White matter
Myelinated axons
Axons surrounded by myelin sheaths
Connects and facilitates communication between different paths of the brain
3 major categories :
Commissures: nerve fibres that connect the left and right cerebral hemispheres (e.g. corpus callosum)
Association Fibres: nerve fibres that connect different regions of the brain on the same cerebral hemisphere
Project fibres: nerve fibres that connect the cerebral cortex with other parts of the brain
Lobes of the brain
Each hemisphere = 4 lobes
Frontal lobe: Voluntary motor functions, concentration, verbal communication, decision making, planning and personality
Parietal lobe: General sensory functions
Occipital lobe: Processing incoming visual information and storing visual memories
Temporal lobe: Hearing and smell
Insula: Final two lobes - require temporal lobe to be retracted. Awareness of body and emotion state, emotional responses, empathy and interpretation of taste
Limbic: emotional, memory and motivational processes
Sulci
The cerebrum is covered by folds/ridges (gyri) and shallows depressions between folds (sulci), which demarcates special regions of the brain and lobes respectively
Gyri
Function to significantly increase the surface area of the brain
Precentral gyrus: Primary motor area of the cerebral cortex controlling voluntary movements
Postcentral gyrus: Primary somatosensory area of the cerebral cortex receiving and processing all somatosensory information
Superior temporal gyrus: Contains the Wernicke’s area - interpret language by recognising speech
Inferior frontal gyrus: Broca’s area, critical for speech production
Homunculus
A special feature about the Primary Motor Cortex and Primary Somatosensory Cortex is the mapped representation of the body along the precentral gyrus and postcentral gyrus.
Face, hands and fingers, which are relatively small parts regions of the body have a much greater representation (aka. more devoted brain cells) on the cortex than say the entire trunk.
Because of this distorted representation of the human body, which we call ‘homunculus’, we have much more ability for both very fine motor skills and greater sensory inputs from different areas of the body.
Cerebellum
Located posterior to brainstem and beneath the occipital lobe of the cerebrum
Highly organised structure composed of folded grey matter
Contains 1/2 of brains neurons
2 hemispheres - mainly highly organised ridges and grooves
Function of cerebellum
Structures within the cerebellum
Medulla Oblongata and Pons: Key parts of brainstem
Tentorium cerebelli: extension of the dura mater separating the occipital lobes and the cerebellum
Cerebellar cortex: outer layer of grey matter folded into folia
Arbor vitae: white matter deep to the grey matter - branched, tree-like appearance
Cerebellar nuclei:
Masses of grey matter deep within the white matter
Four key nuclei when cerebellum is sectioned: Dentate (largest), emboliform, globose and fastigial (Don’t Eat Greasy Food)
Critical roles in fine-tuning motor coordination, balance and motor learning
Basic embryonic development of the brain
Describe and identify the brains stem (midbrain, pons and medulla) and describe its basic functions
Vital structure located at the base and centrally in the brain connecting the cerebral hemisphere with the spinal cord
Serves as a relay centre for transmitting sensory and motor signals between the brain and spinal cord as well as regulating basic life-sustaining functions e.g. HR, breathing and consciousness
3 parts of brain stem and their function
Identify the components of the diencephalon (thalamus, hypothalamus and epithalamus) and describe their basic functions
Region of the brain located between the cerebral hemisphere and the midbrain
Crucial role in sensory processing, homeostasis and regulation of physiological functions in body
3 main structures
thalamus
One in each hemisphere of the brain connected by the intermediate adhesion
Acts as a relay station for sensory information, transmitting signals to the cerebral cortex
Over 50 distinct nuclei
Responsible for:
Relaying sensory impulses
Crude perceptions (pain, temperature, pressure)
Motor function through transmission of impulses from cerebellum and basal ganglia to the primary motor cortex
Regulation of autonomic activities
Maintenance of consciousness
hypothalamus and epithalamus
Hypothalamus:
Below the thalamus
Regulates vital functions e.g. temperature, thirst, hunger, circadian rhythms
Controls body’s hormones through the endocrine system
Considered as the homeostasis centre of the body
Epithalamus
Above and behind thalamus
Consists of pineal gland and habenula
Pineal gland: secretes melatonin (promotes sleepiness, sleep-wake cycles)
Habenula: connections to limbic system (regulates mood, reward processing, stress response, olfaction)
Identify the components of the basal ganglia (caudate nuclei, putamen and globus pallidus) and describe their basic function
Found deep within white matter of the cerebral hemispheres
Group of interconnected nuclei
Nuclei = caudate (green), putamen (blue) and globalus pallidus (light purple and purple)
Regulate voluntary motor control, movement coordination and cognitive functions
Describe the basic functions of the limbic system
Function of emotions, memory, behavioural regulation, pain, pleasure and motivation
Made of limbic lobe, basal ganglia, thalamus, hypothalamus, amygdala and hippocampus
