Central Nervous System Flashcards
Embryonic Development of the Brain
- Neural tube (the brain and spinal cord begins as this and contains neural canal)
- Primary brain vesicles (the anterior/rostral end of neural tube expands into three primary brain vesicles - the prosencephalon/ forebrain, mesencephalon/ midbrain, rhombencephalon/
hindbrain)
PFMMRH = precious forgets monique’s mango right here - Secondary brain vesicles (primary brain vesicles give rise to this by the forebrain divides into telencephalon/endbrain and diencephalon/interbrain, the hindbrain constricts into metencephalon/afterbrain and myelencephalon/spinal brain, midbrain stays the same)
- Adult brain structures
-telencephalon specializes and becomes cerebrum with the two cerebral hemispheres including cortex, white matter
-diencephalon specializes and becomes thalamus, hypothalamus, epithalamus and retina of eye
-mesencephalon becomes midbrain of brain stem
- metencephalon becomes pons of brain stem and cerebellum
-myelencephalon becomes medulla oblongata of brain stem
-hindbrain becomes spinal cord
gray matter
short, nonmyelinated neurons and neuron cell bodies.
white matter
myelinated and nonmyelinated axons
-myelin is what gives white matter its color.
Basic Pattern of the CNS
- central cavity surrounded by grey matter and then white matter on top
- spinal cord matches that
- brain stem has additional grey matter added into the white matter
- cerebellum and cerebral hemispheres has an outer layer of grey matter which is the cortex
Brain Ventricles
-hollow and filled with cerebrospinal fluid and lined by ependymal cells (neuroglia cells) and the ventricles are continuous to one another and with the central canal of the spinal cord
Lateral Ventricle
C-shaped chambers in each cerebral hemisphere
-separated by septum pellucidum
Third ventricle
-each lateral ventricle communicates with the third ventricle in the diencephalum via inter ventricular foramen channel
Fourth Ventricle
-third ventricle is contrinous with the fourth ventricle via the cerebral aqueduct
-lies in the hindbrain dorsal to the pons and superior medulla
-continous with the central canal of the spinal cord
-Has 3 openings: 1 lateral apertures in the side walls on both sides, and the median aperture
Lobes/Fissures of the Brain
(come back)
Elevated ridges of tissue called gyri which are eparated by shallow grooves called sulci mark the entire surface of the cerebral hemispheres
-Deeper grooves, called fissures, separate large regions of the brain
-median longitudinal fissure separates the cerebral hemi- spheres
-transverse cerebral fissure separates the cerebral hemispheres from the cerebellum below
Cerebral cortex
- Site of conscious mind
- allows awareness, sensory perception, voluntary motor initiation, communication, memory
storage, understanding
Contains three types of functional areas:
* Motor areas: control voluntary movement
* Sensory areas: conscious awareness of sensation
* Association areas: integrate diverse information
- Each hemisphere is concerned with contralateral (opposite) side of body
- Lateralization (specialization) of cortical function can occur in only one hemisphere (e.g., language abilities)
- Conscious behavior involves entire cortex in one way or another
Motor area of cerebral cortex
Located in frontal lobe and act to control voluntary movement
Includes =
-Primary motor cortex
-Premotor cortex: Help plan for movements and controls learned, repetitious or patterned movements
- frontal eye fieldL Controls voluntary eye movement
-Broca’s area: present in one hemisphere (usually left), motor speech area, active in planning speech
Sensory area of cerebral cortex
-areas of cortex associated with conscious awareness of sensation
-occur in parietal, insular, temporal, and occipital lobes
-includes olfactory bulb, olfactory tract, and primary olfactory cortex
Multimodal association area of cerebral cortex
- Receive inputs from multiple sensory areas, send outputs to multiple areas
- information flows from sensory receptors to primary sensory cortex, to sensory association cortex and then to multimodal association cortex
- Allows us to give meaning to information received, store in memory, tie to previous
experience, and decide on actions
-This is where Sensations, thoughts, emotions become conscious: makes us who we are
- Divided into three parts: anterior association area, posterior association and limbic association areas
Anterior Association area
-ALSO CALLED PREFRONTAL CORTEX
-involved with intellect, cognition, recall and personality
-contains working memory
-tumors cause mental and personality disorders
Posterior Association Area
-contains parts of the temporal, parietal and occipital lobes
-plays a role in recognizing patterns and faces, localizing us in space
-involved in understanding written and spoken language
-lesions cause an issue with a person’s awareness in space (e.g., they may not wash the body opposite to the side the lesion is on)
