Chapter 12 part 1) CNS Flashcards
1
Q
Cephalization
A
- Development of the Anterior poriton of the CNS
- Results in increased nueron numbers
- Highest level of nuerons reached in Brain
2
Q
Brain Development (steps)
A
- Brain and Spinal chord begin as the Nueral Tube
- Nueral Tube Expands and constricts to from Three Primary Vessicles
- Prosencephalon) or Forebrain
- Mesencephalon) Midbrain
- Rombencephalon) Hindbrain
- Primary Vessicles become secondary vessicles
- Forebrain) Becomes Telencephalon and Diencephalon
- Telecephalon) Forms cerebral hemisphieres (Cerebrum)
- Diencephalon) Becomes epithalamus, thalamus, hypothalamus, and retina.
- Midbrain) Remains as the Mesencephalon
- Hindbrain) Becomes metencephalon and myelencephalon
- Menencephalon) becomes pons and cerbellum
- Myelencephalon) Becomes medulla oblongata
- Central Cavity) becomes the ventricles.
- Forebrain) Becomes Telencephalon and Diencephalon
3
Q
Why Does brain fold?
A
Spinal chord develops slower than the Brain. Folds are there to save space.
- Forebrain moves toward brainstem and crease/ fold while doing so.
4
Q
Brain Regions (four)
A
- Cerebral Hemispheres
- Diencephalon
- Brainstem (Midbrain, Pons, Medulla)
- Cerebellum
5
Q
White and Grey Matter
(Definition and Location)
A
- Grey matter) short, unmylinated nuersons and cell bodies.
- White Matter) Mylinated. Some axons are unmyelinated.
- Basic Pattern In CNS) Grey matter covers the outside of the brain. Inside of brain is made of white matter.
- Cerebrum and Cerebellum have scattered areas of grey matter called nuclei.
6
Q
Ventricles
A
- Ventricles) Fluid-Filled chambers that are continuous to one another
- Filled with cerebrospinal fluid (CSF), lined by ependymal cells.
- Four Major Ventricles
- Paried Lateral Ventricles) Large C-shaped chambers located in each hemisphere
- Seperated by membranous septum pellucidum.
- Connected to third ventricle via interventricular foramen
- Third Ventircle) Lies in Diencephalon
- Connected to fourth ventricle via cerebral aquaduct.
- Fourth Ventricle) Lies in Hindbrain. Continuous with spinal chord.
- Paired Lateral Apertures and Median Aperture connect fourth ventricle to subarachnoid space (surrounds brian)
- Paried Lateral Ventricles) Large C-shaped chambers located in each hemisphere
7
Q
Cerebral Hemispheres
A
- Cerebral Hemispheres) form superior part of the brain.
- Account for most (83%) of brain mass
- Gyri) ridges on surface of brain
- Sulci) Shallow grooves
- Central Suculus) Seperates Precentral and Postcentral Gyrus of parietal lobe
- Parieto-Occupital Sulus) seperates occipital and parietal lobes
- Lateral sulcus) outlines temporal lobe
- Fissures) Deep grooves.
- Longitudinal Fissure) Seperates two hemisphieres
- Transverse Cerebral Fissure) Seperates Cerebrum and Cerebellum
- Suculi Divide each hemisphere into five lobes
- Frontal
- Parital
- Temporal
- Occipital
- Insula) burried deep within laterl sulcus.
8
Q
Cerebral Cortex
A
- Enables awarness and voluntrary movments,
- Thin, superfical layer of grey matter
- Made of nueron cell bodies, dendrited and glial cells and blood vessels (no Axons)
- 40% of brain mass
9
Q
Four Considerations of Cerebral Cortex
A
- Made of three functional areas
- Motor Areas) control voluntray movment
- Sensory areas) conscious awareness of
sensation - Association areas) integrate diverse information
- Each hemisphere is concerned with colateral (opposite) side of body
- While symmetrical in structure, the two hemispheres are not equal in function. They are laterally specialized and some functions can only appear in one hemisphere.
- No Functional are of the cortex acts alone.
- Behivior involves entire cortex in one way another.
10
Q
Motor Areas
A
- Located in frontal lobe, motor areas act to control voluntary movement
- Primary motor cortex) in precentral gyrus
- Premotor cortex) anterior to precentral gyrus
- Broca’s area) anterior to inferior premotor area
- Frontal eye field) within and anterior to premotor cortex; superior to Broca’s area
11
Q
Primary (somatic) Motor cortex
A
- Located in precentral gyrus of frontal lobe
- Pyamidal Cells) Large nuerons that allow conscious control of percise, skilled, skeletal muscle movnebts
- Pyramidal (cortico spinal tracts) Formed by axons of pyramidal cells that project down spinal chord.
- Somatotopy) Mapping all muscles back to their control center on primary motor cortex)
12
Q
Premotor Cortex
A
- Helps plan movments. Selects and sequnces basic tasks into more complex tasks
- Uses processed sensory information to make more informed descisions
13
Q
Brocas Area
A
- Only found in one hemisphere (usually left)
- Directs the muscles of speech production
14
Q
Frontal Eye Field
A
- Controls Voluntary Eye movments.
15
Q
Homestatic Imbalance To Motor Cortex
A
- Primary Motor Cortex) paralyzes muscles controled by that area
- Paralysis occurs on opposite side of the body than damage.
- Only voluntary control is lost
- Premotor Cortex) Loss of moter skills programed by that area, but does not impair muscle movments.
16
Q
Sensory Areas
A
- Sensory areas) Areas of cortex concerned with conscious awareness of sensation
- Occur in parietal, insular, temporal, and occipital lobes
- Eight main areas include
- primary somatosensory cortex,
- somatosensory association cortex
- visual areas
- auditory areas
- vestibular cortex
- olfactory cortex
- gustatory cortex
- visceral sensory area
17
Q
Primary Somatosensory Cortex
A
- Located in postcentral gyri of parietal lobe
- Recives sensory information from skin, muscles, joints and tendons.
- Spatial Dicrimination) Identificaton of body part being stimulated.
18
Q
Somatosensory association cortex
A
