Introduction To Brain, Cranial Meninges And Blood Supply Flashcards
4 main parts of the brain
Cerebrum
Cerebellum
Diencephalon
Brainstem
Where is the cerebrum
Largest part covering the superior and lateral aspects of the brain, covered in folds of tissue
Division of cerebrum
Made up of 2 hemispheres each divided into 4 lobes
Where is the cerebellum
Smaller, bolbous structure underneath the posterior part of the cerebrum
What is the location of the Diencephalon
Area is deep within the brain, beneath the cerebrum but above the brain stem
Where is the brain stem
Connects the cerebrum and Diencephalon to the spinal cord
Function of the frontal lobe
Contains the primary motor cortex involved in planning and executing conscious movement
Contains the prefrontal cortex involved in behaviour, personality and decision making
Function of the primary motor cortex
Planning and executing conscious movement
Function of the prefrontal cortex
Behaviour, personality and decision making
Function of the temporal lobe
Contains the primary auditory cortex responsible for processing auditory information
Contains the hippocampus involved in formation of memories
Function of the hippocampus
Formation of memories
Function of the parietal lobes
Contain the primary somatosensory cortex involved in processing sensory information
Function of the primary somatosensory cortex
Processing sensory information
Function of the primary auditory cortex
Processing auditory information
Function of the occipital lobe
Contains the primary visual cortex responsible for processing visual information
Function of the primary visual cortex
Processing visual information
Function of the cerebellum
Helps maintain posture, balance and corrects fine movements
Function of the brain stem
Connects the rest of the brain to the spinal cord
Contains the nuclei of cranial nerves and vital centres for regulation of breathing and cardiovascular function
Gyri
Folds/ridges of the exterior aspect of the brain
SuIci
Furrows/grooves in between the gyri
Central sulcus
Large sulcus in the coronal plane separating the frontal and parietal lobes
One on both hemispheres
Lateral sulcus (Sylvian fissure)
Large sulcus in the transverse plane separating the temporal lobe from the frontal and parietal lobes
One on both hemispheres
Insula
Part of the cerebral cortex that can only be seen by opening the lateral sulcus
Opercula
The parts of the frontal, parietal and temporal lobes that cover the insula
Longitudinal fissure
Large groove separating the two hemispheres
Corpus callosum
A large bundle of white matter that connects the two hemispheres
Olfactory tracts
Nerve fibres carrying information about smell from the nasal cavity
Run along the inferior surface of the frontal lobes on each side of the
Optic nerve
Carry visual information from the retina
On inferior surface of frontal lobe and pass posteriorly and medially to a point where they party cross over each other (optic chiasm)
Optic chiasm
Point where 2 optic nerves partly cross over each other
Mammillary bodies
Rounded structures found behind the optic chiasm and pituitary gland
Part of Diencephalon
Hypothalamus
Part of Diencephalon
Only just visible behind the optic chiasm
Mammillary bodies located on its inferior surface
What is the hypothalamus part of
Diencephalon
Crus cerebri
Pillars of white matter next to the mammillary bodies that connect the brain to the brain stem
Form part of the cerebral peduncles (part of the midbrain)
Interpeduncal fossa
Fossa between the cerebral peduncles
May have a layer of arachnoid matter overlying it
Parts of the brain stem
Midbrain
Pons
Medulla oblongata
Location of the midbrain
Most superior part of brain stem where the crus cerebri are located
Location of the pons
Large, bulbous, central part of brain stem
Location of the medulla oblongata
Most inferior part of the brain stem that tapers down to become the spinal cord inferiorly
Cerebellum
Lined with many small fissures and is made up of 2 hemispheres connected by a central vermis
Connects to the brainstem
What connects the 2 hemispheres of the cerebellum
A central vermis
Functional areas of the frontal lobe
Primary motor cortex
Pre motor cortex
Prefrontal cortex
Broca’s area
Functional areas of the parietal lobe
Primary somatosensory cortex
Functional areas of the temporal lobe
Primary auditory cortex
Hippocampus
Amygdala
Wernicke’s area
Functional areas of the occipital lobe
Primary visual cortex
Location of the primary motor cortex
Most posteriorly in the frontal lobe
Immediately anterior to the central sulcus
Location of Broca’s area
Inferior frontal lobe of the dominant hemisphere (usually left0
Which hemisphere is usually dominant
Left
Anterior to posterior frontal lobe functional areas
Prefrontal cortex
Premotor cortex
Primary motor cortex
Function of the primary motor cortex
Execution of motor function
Function of the premotor cortex
Planning and preparation of movements
Function of the prefrontal cortex
Personality, behaviour, problem solving, impulse control and inhibition, social and sexual behaviour
Function of Broca’s area
Spoken language production
Location of the parietal lobe
Central sulcus to the parietooccipital fissure
Location of the primary somatosensory cortex
Immediately posterior to the central sulcus
Role of the dominant parietal lobe (left)
Perception and mathematical and language operations
Role of the non-dominant parietal lobe (right)
Visuospatial function
Location of the primary auditory cortex
Immediately below the lateral sulcus
Location of the hippocampus
Inferior and medially in the temporal lobe
Location of the amygdala
Deep within the temporal lobe
Role of amygdala
Perception of fear
Location of wernicke’s area
Most superior and posterior part of dominant temporal lobe
Function of wernicke’s area
Understanding and coordination spoken language
Location of the occipital lobe
Most posterior part of cerebrum
Limbic system contains
Group of structures found in the medial margins of the hemispheres, including the hippocampus, amygdala and parts of the cortex
Also contains the Diencephalon
Function of limbic system
Involved in emotion, memory and behaviour
Influence over the endocrine function of the body
Parts are specifically related to sensations of fear, pleasure and rewarding behaviours
Homunculus
Mapping of specific parts of the body to parts of the cortex (the gyri)
There is a motor and sensory cortices
Where are the face and mouth represented in the homunculus
On the lateral aspects of the primary motor and somatosensory cortices
Where are the upper limb and torso represented in the homunculus
Most superior part of the cortex
Where are the feet represented in the homunculus
Most medial part of the cortices
Cranial meninges
3 layers of tissue that envelop the brain and spinal cord
3 layers of cranial meninges
Dura mater
Arachnoid mater
Pia mater
Dura mater
Most external, lying against the skull
It is fibrous, thick and does not stretch
Arachnoid mater
Intermediate layer
It is much thinner and more flexible
Resembles a spider’s web
Pia mater
Most internal- lies on surface of the brain
It is very thin (cannot be seen with the naked eye)
Layers of matter from skin to cerebral cortex
Skin
Aponeurosis
Periosteum
Skull
Dura mater (endosteal layer and meningeal layer)
Arachnoid mater
Subarachnoid space
Pia mater
Cerebral cortex
2 layers of dura mater
Outer Endosteal layer
Inner Meningeal layer
Outer endosteal layer
Layer of dura
Adherent to interior of the skull
Inner meningeal layer
Layer of dura
Completely envelops the brain and spinal cord
Peels away from the endosteal layer in certain places and folds down into the brain to form a double layer of dura that separates certain parts of the brain
Falx cerebri
A double layer of folded dura lying in the longitudinal fissure that separates the 2 hemispheres
Tentorium cerebelli
A double layer of folded dura that separates the occipital lobe and cerebellum
Falx cerebelli
Separates the 2 lobes of the cerebellum
Dural venous sinuses
Channels between the outer endosteal layer and inner meningeal layer filled with venous blood
What separates the cerebellum and occipital lobe
Tentorium cerebelli
Superior sagittal sinus
Formed in the space between the 2 layers of dura
Located superiorly and runs along the top of the brain in the sagittal plane
Inferior sagittal sinus
A smaller version of the superior sagittal sinus
Runs in same direction but is located inferior to it
Lies on top of the corpus callosum
Formed as the meningeal layer of dura that forms the Falx cerebri folds back on itself in the longitudinal fissure