brain Flashcards
What structure forms during the 3rd and 4th week of embryological development?
The neural tube forms during the 3rd and 4th week of embryological development.
What happens to the cranial end of the neural tube during development?
The cranial end of the neural tube bulges and separates into three primary vesicles during development.
How many secondary vesicles are eventually produced from the cranial end of the neural tube?
Two of the three primary vesicles divide further, eventually producing five secondary vesicles.
What structures do the secondary vesicles at the cranial end give rise to?
The secondary vesicles at the cranial end will give rise to the cerebrum.
What structures arise from the vesicle caudal to those forming the cerebrum?
The vesicle caudal to those forming the cerebrum will give rise to the thalamus and hypothalamus.
What do the remaining three vesicles eventually form?
The remaining three vesicles will eventually form the brainstem and cerebellum.
How many “primary vesicles” does the cranial end of the neural tube separate into?
The cranial end of the neural tube separates into three “primary vesicles”.
What happens to two of the primary vesicles during development?
Two of the primary vesicles further sub-divide during development, giving rise to five “secondary vesicles”.
What do the walls of these vesicles form?
The walls of these vesicles form specific regions of the brain.
What do the fluid-filled cavities within these vesicles form?
The fluid-filled cavities within these vesicles form the ventricles and canals of the brain.
What is the largest region of the brain?
The largest region of the brain is the highly folded cerebrum.
What is located inferior to the posterior end of the cerebrum?
Inferior to the posterior end of the cerebrum is the cerebellum.
What is the name of the stock-like structure that extends from the inferior surface of the brain?
The stock-like structure is the brainstem.
What is located at the cranial end of the brainstem?
At the cranial end of the brainstem is the diencephalon.
What structures form the walls and ceiling of the diencephalon?
The walls and ceiling of the diencephalon form the thalamus.
What structure forms the floor of the diencephalon?
The floor of the diencephalon forms the hypothalamus.
What are the three sections of the brainstem?
The three sections of the brainstem are the midbrain, pons, and medulla oblongata.
what is the largest potion of the brain?
cerebrum
What is the core composition of the cerebrum?
The cerebrum contains a core of white matter surrounded by a layer of highly folded gray matter.
What is white matter composed of?
White matter is composed of myelinated axons.
What is gray matter composed of?
Gray matter is composed of unmyelinated axons and cell bodies.
What are the elevated ridges on the surface of the cerebrum called?
The elevated ridges on the surface of the cerebrum are referred to as gyri.
What are the depressions between the gyri called?
The depressions between the gyri are referred to as sulci or fissures.
How is the cerebrum divided?
The cerebrum is divided into left and right hemispheres.
What separates the left and right hemispheres of the cerebrum?
The left and right hemispheres of the cerebrum are separated by a deep depression called the longitudinal fissure.
What is located at the base of the longitudinal fissure?
At the base of the longitudinal fissure is a mass of white matter called the corpus callosum.
What structure is located at the “floor” of the longitudinal fissure?
At the “floor” of the longitudinal fissure is the corpus callosum, a mass of transversely running axons that connect the left and right hemispheres.
What does the cerebral white matter consist of?
The cerebral white matter consists of several tracts of axons that transmit signals between various portions of the cerebrum.
What do association tracts connect?
Association tracts connect regions of the same hemisphere.
What do commissural tracts connect?
Commissural tracts connect analogous regions of the two hemispheres, with the largest being the corpus callosum.
What do projection tracts carry signals between?
Projection tracts carry signals between the cerebrum and other portions of the brain and spinal cord.
What is the function of the corpus callosum?
The corpus callosum is the largest of the commissural tracts whose axons transmit signals between the left and right hemispheres.
Besides commissural tracts, what other types of tracts are found in the cerebrum?
In addition to commissural tracts, the cerebrum also contains association tracts whose axons transmit signals between regions of the same hemisphere.
What do association tracts do?
Association tracts transmit signals between regions of the same hemisphere.
What are projection tracts responsible for?
Projection tracts transmit signals between the cerebrum and other regions of the brain and spinal cord.
How is the cerebral grey matter (cortex) divided in each hemisphere?
In each hemisphere, the cerebral grey matter (cortex) is divided into 4 lobes that are separated by prominent sulci.
How are the cerebral hemispheres divided into lobes?
The cerebral hemispheres are divided into four lobes by prominent depressions, with their names mirroring the cranial bones superficial to them.
Which lobe of the cerebrum lies deep to the frontal bone?
The frontal lobes of the cerebrum lie deep to the frontal bone.
Which lobe of the cerebrum lies deep to the parietal bones?
The parietal lobes lie deep to the parietal bones.
Which lobe of the cerebrum lies deep to the temporal bones?
The temporal lobes lie deep to the temporal bones.
Which lobe of the cerebrum lies deep to the occipital bone?
The occipital lobes lie deep to the occipital bone.
What separates the frontal and parietal lobes in each hemisphere?
The frontal and parietal lobes in each hemisphere are separated by the central sulcus.
What separates the frontal and temporal lobes in each hemisphere?
The frontal and temporal lobes in each hemisphere are separated by the lateral sulcus.
What separates the parietal and occipital lobes in each hemisphere?
The parietal and occipital lobes in each hemisphere are separated by the parietal occipital sulcus.
What is the general function associated with the frontal lobe?
The frontal lobe is associated with motor functions and higher functions.
What are the major functional areas associated with each lobe of the cerebrum?
The major functional areas associated with each lobe of the cerebrum include motor functions and higher functions in the frontal lobe, and sensory functions in the parietal, temporal, and occipital lobes.
What is the general function associated with the parietal, temporal, and occipital lobes?
The parietal, temporal, and occipital lobes are generally associated with sensory functions.
What has allowed for the development of a map of functional areas specific to each lobe of the cerebrum?
The relatively constant organization of functional areas between individuals has allowed for the development of a map of functional areas specific to each lobe of the cerebrum.
What function is associated with the primary motor area of the frontal lobe?
The primary motor area of the frontal lobe is associated with the initiation of voluntary movements.
What is the function of the premotor area in the frontal lobe?
The premotor area in the frontal lobe serves as a “memory bank” of learned movements.
What functions are associated with the prefrontal cortex in the frontal lobe?
The prefrontal cortex in the frontal lobe is associated with “higher functions” such as intellect, learning, memory, planning, judgment, personality, and mood.
Besides voluntary movements, what other functions are associated with areas in the frontal lobe?
Areas in the frontal lobe are also involved in the articulation of speech and the recognition of olfactory stimuli (odours).
What areas are contained within each frontal lobe?
Each frontal lobe contains the primary motor area, pre-motor area, and prefrontal cortex.
Where is the primary motor area located within the frontal lobe?
The primary motor area is located in the precentral gyrus, immediately anterior to the central sulcus.
What is the function of the primary motor area?
The primary motor area is responsible for initiating voluntary movements
What does the motor homunculus represent?
The motor homunculus represents the portions of the cortex responsible for initiating movements in various regions of the body.