Chapter 13 Flashcards
the brain!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
four main regions of the brain
cerebrum, diencephalon, brainstem, cerebellum
gyri
ridges
sulci
depressions between ridges
fissures
deep sulci
gray matter
neuron cell bodies, dendrites, unmyelinated axons
cortex
superficial to gray matter
nucleus in gray matter
the region of gray matter; cluster of cell bodies
white matter
myelinated axons
tracts
bundles of myelinated axons
neurulation
formation of nervous tissue
when does neurulation begin?
3rd week of embryonic development
neural tube in the embryo
develops into CNS
step 1/3 of neurulation
neural plate formation - cells at the neural plate margin will become neural folds
step 2/3 of neurulation
tips of folds become neural crest cells; groove deepens, folds rise and “pinch” together
step 3/3 of neurulation
neural crest cells separate from neural folds and form other structures
neural tube formation
folds meet to form neural tube
neural tube surrounds:
neural canal
neuropores
openings at the end of neural tubes
when do neuropores close?
4th week of embryonic development
three primary vesicles
forebrain, midbrain, hindbrain
prosencephalon
forebrain
mesencephalon
midbrain
rhombencephalon
hindbrain
when do primary vesicles form?
late 4th week from the neural tube
secondary vesicles (8)
cerebrum
thalamus
hypothalamus
epithalamus
midbrain
pons
cerebellum
medulla oblongata
telencephalon
becomes cerebrum
diencephalon
becomes thalamus, hypothalamus, epithalamus
mesencephalon (2ndary vesicle)
becomes midbrain
metencephalon
becomes pons and cerebellum
mylencephalon
becomes medulla oblongata
anencephaly
substantial/complete absence of the brain
spina bifida
failure to close caudal part of neural tube
cystica
no formation of vertebral arch, have large cyst instea
occults
partial defect of bony arch
brain development @ 13-26 weeks
telencephalon envelops diencephalon; develops surface folds
brain development @ birth
brain fits in cranial cavity; most gyri and sulci are present
ventricles
cavities in brain
cerebrospinal fluid
contained within ventricles (CSF) and subarachnoid space; clear/colorless
ventricles are lined with:
ependymal cells
four ventricles in the brain
2 lateral ventricles in cerebrum (separated by septum pellucidum)
3rd ventricle in diencephalon (connects to lateral ventricles by interventricular septum
4th ventricle between pons and cerebellum (connects to 3rd ventricle by cerebral aqueduct)
septum pellucidum
partition between 2 lateral ventricles in cerebrum
interventricular septum
connects 3rd ventricle to lateral ventricles
cerebral aqueduct
connects 4th ventricle to 3rd ventricle
cerebral aqueduct
connects 4th ventricle to 3rd ventricle
which ventricle merges with the central canal of the spinal cord?
4th ventricle
functions of CSF
buoyancy (reduces brain weight)
protection (liquid cushion)
environmental stability (nutrient/waste transport)
CSF is formed by:
choroid plexus within ventricles
CSF drained through:
dural venous sinuses
blood-brain barrier
regulates what enters interstitial fluid of the brain
less blood-brain barrier in what regions?
choroid plexus, hypothalamus and pineal gland
cerebrum
origin of all complex intellectual functions
functions of cerebrum
intelligence/reasoning
thought/judgment
voluntary control (skeletal muscle)
conscience/senses
longitudinal fissure
separates left/right hemispheres
corpus callosum
connects hemispheres
hemispheres of brain
left controls right side of body, right controls left
5 lobes of cerebrum
frontal, parietal, temporal, occipital, insula
frontal lobe
biggest lobe of the brain; anterior to central sulcus
pre central gyrus
primary motor cortex of frontal lobe; voluntary movement
functions of cerebrum
motor control of muscles (on opposite side)
concentration
verbal communication
decision making
planning
personality
prefrontal cortex
responsible complex thought, judgment, personality, planning, deciding (not fully developed in adolescents)
Broca’s area
movements for vocalization (left side only)
parietal lobe
posterior to central sulcus