The brain Flashcards
mesencephalon
(midbrain)
an expansion caudal to the prosencephalon
Prosencephalon
(forebrain)
at the anterior tip of the neural tube
rhombencephalon
(hindbrain)
most caudal of the primary vesicles, continuous with the spinal cord
@ 5 weeks of development, what are the subdivisions of the prosencephalon? What is the function of the subdivisions?
diencephalon: becomes major relay and processing centre for info headed to and from the cerebrum
telencephalon: begins to expand rapidly to become cerebrum
@ 5 weeks of development, what are the subdivisions of the rhombencephalon?
metencephalon: caudal to the midbrain, will form the cerebellum and the pons
myelencephalon: becomes medulla oblongata
what is the function of the cerebral cortex?
conscious thought, memory storage and processing, sensory processing and regulating skeletal muscle contractions
What are fissures, Gyri and sulci?
fissures: deep grooves that subdivide each hemisphere
gyri: folds in the cerebral hemispheres that increase its SA
sulci: shallow grooves in the cerebral hemispheres that separate adjacent gyri
What is the function of the thalamus?
contains relay and processing centres for sensory information
what is the function of the hypothalamus?
contains centres involved with emotions, autonomic function and hormone production
What is the diencephalon? What parts of the brain are included in it?
- the structural and functional link between cerebral hemispheres and the rest of the CNS
thalamus and hypothalamus
What is included in the brainstem?
midbrain, pons and medulla oblongata
What is the function of the midbrain?
- contains nuclei that process visual and auditory information and control relaxes triggered by these stimuli
- maintains consciousness
What is the function of the pons?
- connects cerebellum to brainstem
- functions in somatic and visceral motor control
What is the function of the medulla oblongata?
relays sensory info to other parts of the brain
- autonomic functions such as heart rate and BP
What is the function of the cerebellum
coordinating and modulating motor commands from the cerebral cortex
Where are the lateral ventricles?
in each cerebral hemisphere
How do the lateral ventricles communicate with the third ventricle?
via the ventricular foramen
Where is the third ventricle located?
in the diencephalon
What connects the third and fourth ventricles of the brain?
the cerebral aquaduct
Where is the fourth ventricle?
begins in the mesencephalon and extends into the superior portion of the medulla oblongata
what is the corpus callosum?
a thick tract of white matter that interconnects the two cerebral hemispheres
What is the septum pellucidum?
a thin partition that separates the two lateral ventricles
What are dural folds?
inner layer of dura mater that extends into the cranial cavity– they dip inwards, then return
What are dural venous sinuses?
large collecting veins located within the dural folds
What is the tentorium cerebelli?
a venous sinus that separates the cerebral hemispheres from the cerebellum
What is the falx cerebelli?
a venous sinus that separates the two cerebellar hemispheres along the midsagittal line inferior to the tenorium cerebelli
What is the falx cerebri?
a fold of dura mater between the cerebral hemispheres
What are the three functions of CSF?
1: support weight of brain
2: cushioning the brain and spinal cord against physical trauma
3: transporting nutrients, chemical messengers and wastes
What produces CSF?
choroid plexus (located in each ventricle)
What are arachnoid granulations and what is their function?
finger like extensions of arachnoid membrane that penetrates the meningeal layer of the dura mater and extends into the superior sagittal sinus
function: CSF is absorbed into the venous circulation
How does the CSF reach the subarachnoid space?
through two lateral apertures and a single median aperture in the roof of the fourth ventricle
what is the limbic system? what are the functions of the limbic system?
a functional group of tracts and nuclei located in the cerebrum and diencephalon
functions:
1) establishing emotional states
2) linking the conscious/intellectual functions of the cerebral cortex with the unconscious and autonomic functions of the brainstem
3) facilitating memory storage and retrieval
4) affecting motivation
What are the components of the limbic system?
in the diencephalon:
- anterior thalamic nuclei, hypothalamus, mammillary body, reticular formation
in the cerebrum:
- cingulate gyrus, parahippocampal gyrus, dentate gyrus
- fornix
- amygdala, hippocampus
What is the function of the amygdaloid body?
interface among the limbic system. cerebrum and other sensory systems
- regulation of heart rate and fight or flight, links emotions with memories
What is the function of the hippocampus?
elongated nucleus, important in learning, especially in the storage and retrieval of long term memories
What are the basal nuclei
masses of gray matter that lie within each cerebral hemisphere
provides subconscious control of skeletal muscle tone and help coordinate learned movement patterns
- once movement is underway the basal nuclei provide the general pattern and rhythm especially for movements of the trunk and limbs
What are the functions of the left cerebral hemisphere?
language based skills (reading, writing, speaking), mathematics and logic
What are the functions of the right cerebral hemisphere ?
analyzes sensory info, recognizes faces and 3D relationships, emotional context
