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Areas of The Brain - Coggle Diagram
Areas of The Brain
Cerebrum
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Made up:
*Gray Matter: surface of brain-Thinking side/action cell bodies, contains dendrites + Somas of neurons (signals received and processed here)*White Matter: Deep to gray matter - Communication/Mylienated axons, responsiblle for sending signal from one place to another
- Basal Nuclei: islands of grey matter in middle of brain--> coordinate and produce smooth movement
Hemispheres:
- Contralateral control (Left side of brain controls right side of body vice versa)
- Some abilities localised to one side
-Left= Analytic thought, logic, language and science and math
-Right= Holistic thought, intuition, creativity and Art and Music
Cortex:
*Location of Conscious mind=thought processes, intellectual functions, memory storage & processing
- Localises & interprets sensory inputs
- regulation of skeletal muscle activity
Cerebral hemisphere 3 functional areas:-Sensory areas - Association areas-when you start to think about it e.g. primary visual area= seen something,Visual association area = know what it is-Motor areas - each cortex deals with contralateral body side's sensory and motor functions
Full structure:
*Anatomical features:
*Sulcus (one)/**Suci=Valley="Grooves" of brain)*
*Gyrus (one)/Gyri=Hill= Raised portions of brain
*Central Sulcus=separates frontal and Parietal lobes
*Lateral sulcus= visible from side view distinguishes between temporal lobe and parietal lobe
Cerebellum
- *2nd largest part of brain
- Location: Behind Brainstem, below occipital lobes of cerebrum
- Controls: Subconscious skeletal muscle contractions for Smooth
- many structural and functional similarities to the cerebrum
- two hemispheres, each with lobes (anterior and posterior)
- superficial cortex of grey matter --> has sensory and motor maps of the body
- deep white matter --> branches like a tree "arbor vitae"
- penduncles - three paired fibre tracts --> permits communication between cerebellum and the rest of the brain
Function:
- coordinate the motor activities initiated by the primary motor cortex
- motor cortex 'informs' the cerebella of its motor plan
- cerebellum receives sensory information from --> proprioceptors through the body, visual and equilibrium pathways --> evaluates body position and movement
- Cerebellum compares the 'plans' with the 'actions' and adjusts the output of the primary motor cortex so the resulting muscle actions are balanced, smooth and coordinated
- monitors and adjusts muscle tone and body position --> maintains posture and balance
Brain stem
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Pons:
Pons = bridge
Contains:
- Fibre tracts ('bridge various brain areas) that...
--> Relay info from the Thalamus --> Cerebellum
--> Relay info between the motor cortex & the cerebellum
- Various Somatic and visceral motor nuclei
--> concerned with sleep, hearing equilibrium, taste, eye movement, facial expression and sensation, respiratory rhythms, swallowing, bladder control and posture
Medulla Oblongata
--> Inferior portion of the brainstem, blends into the spinal cordConducting pathway Brain <--> Spinal cord
- relays sensory information between different brain areas --> thalamus, other portions of the brain stem, cerebellum (muscle stretch and joint positions)
- Autonomic reflex centres - motor nuclei, regulated by the hypothalamus, which regulate visceral functions / survival needs:
- Cardiovascular centre
--> Cardiac centre - controls force and rate of heart contraction
--> Vasomotor centre - adjusts blood vessel diameter
- Respiratory centre
--> controls rate and depth of breathing
- Centres regulating visceral functions:
--> vomiting, hiccupping, swallowing, salivation, coughing, sneezing, speech, gastrointestinal secretion
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Sensory Areas
[General senses] - Somatosensory stimuli (pain, touch, temperature) --> have receptors all over the body, and are processed in somatosensory areas
Primary somatosensory cortext - first time / detection of the sensation --> located in the post-central gyrus (behind the central sulcus) of the parietal lobes**
- Receievs somatosensory information (pain, touch, pressure, vibration) from general sensory.
- Receptors are located in the skin, skeletal muscles, joints and tendons
- Receives information on the body position from proprioceptors in the skeltal muscles, joints and tendons
Somatotopic organisation
- stimulus destination indicates site of origin
- the amount of sensory cortex devoted to a particular body region is related to that region's sensitivity (more sensory receptiors = greater sensitivity = greater area of cortex required to analyse incoming info)
Somatosensory Association Cortex
- located posterior to the primary somatosensory cortex in the parietal lobe
- Interprets incoming sensory information by comparing it to stored memories of past sensory experiences
- Damage = loss of ability to identify objects by touch alone
[Special senses] - (vision, hearing, taste, smell, balance) --> have a specific structure for their detection (ie eyes for vision), and have their own areas of the brain where the information is processed
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[Other
sensory areas]
Olfactory cortex (smell)
- temporal lobe
- conscious awareness of odour
Viseral cortex (viseral)
- Insula
- Perception of visceral sensations e.g. upset stomach, full bladder
Gustatory cortex (taste)
- Insula (deep to the temporal lobe)
- perception of taste
Vestibular (equilibrium) cortext (balance)
- Insula
- Awareness of balance
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Motor Areas
Primary motor cortex
- located in the pre-central gyrus of the frontal lobe
- plans and initiates all voluntary motor activity
- contains the cell bodies of upper motor neurons of somatic motor pathways
- directs movement of skeletal muscles via somatic motor pathways which control the contralateral side of the body (right primary motor cortex controls skeletal muscles on the left side of the body and vise versa)
- specific areas of the primary motor cortex are devoted to controlling specific body party
- somatic organisation
- the amount of motor cortex devoted to controlling a body part is indicative if the complexity and precision of the movements of that body part e.g. hands and face
- damage = paralysed the skeletal muscles controlled by the damaged area - voluntary movements only, not reflexive movement
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Frontal eye field
- directs muscles involved in eye movements
Broca's Area
- directs the muscles involved in speech generation (in only 1 hemisphere)
The premotor Area, Broca's Area and Frontal eye field all:
- contain 'memory banks' e.g. for complex motor activities
- coordinate the movement of several muscle groups
- act via the primary motor cortex
Diecephalon
- mid-sagittal section of the brain
Thalamus
- Bilateral egg-shaped collection of nuclei
- Acts as a relay station for sensory information coming into the cerebral cortex --> 'gateway to the cerebral cortex'
- sorts and edits sensory information and conducts it to the relevant areas of the cerebral cortex e.g. somatosensory information
- conducts impulses between the cerebral motor areas and the cerebellum
- involved in cortical arousal (alterness), learning and memory processing
Hypothalamus
- small structure (below the thalamus)
- collection of nuclei with many vital functions
- Chief integration centre of the autonomic nervous system - regulates the ANS by controlling centres in the brain stem and spinal cord i.e. cardiac and regulatory function
- Centre for emotional response - part of the limbic system
- Thermoregulatory centre - monitors and regulates body temperature
- Regulation of food intake - appetite and satiety
- Regulation of water balance by monitoring plasma Na+ concentration and triggering the release of anti-diuretic hormone (ADH) and prompting thirst and reduce urine output
- Regulation of sleep-wake cycles - biological clock
- controls endocrine system functioning - primarily via the pituitary gland
Epithalamus
- epi = on top (above the hypothalamus)
- most posterior portion if the dicephalon
- incorporates the pineal gland
- produces melatonin --> induces sleep
- helps the hypothalamus regulate sleep-wake cycles
Acts as a sensory filter - cuts of 99% of sensory input
- filters out repetitive, familiar or weak signals
- allows strong or unusual stimuli to reach cerebral cortex and consciousness
Contain the reticular activating sytem
- maintains cortical alterness (consciousness) by regulaing sensory input to the cerebrum
- inhibited by sleep centres in the hypothalamus
- depressed by alcohol
- Extends through the central core of the brain stem
- Projection fibres to the cerebral cortex, thalamus and other brain areas