CNS structure & ventricles organization & development Flashcards
DAYS 2-3 - WHAT HAPPENS
7 STAGES OF FORMATION OF MORULA & BLASTOCYST
WHAT ARE THE 3 PARTS OF THE BLASTOCYST & WHAT DO THE 2 MAIN PARTS FORM
Rapid cell division
- pronuclear stage - 1 day after retrieval
- 2-Cell stage - 1.5 days after
- 4-Cell stage - 2 days after
- 8-Cell stage - 3 days after
- Morula - 4 days after
- Early Blastocyst - 5 days after
- Expanded Blastocyst - 5.5-6 days after
Inner cell mass - forms embryo
Trophoblas - contributes to placenta
Blastocoel
WEEK 2 - WHAT HAPPENS
Inner cell mass continuous to grow and organizes into a bilaminary germ disc
WHAT ARE THE 3 PARTS OF THE GERM DISC
Epiblast
Hypoblast
Amniotic Cavity
WEEK 3 - WHAT HAPPENS & HOW
Gastrulation: Development of trilaminar germ disc
Epiblast invaginates to form the mesoderm and endoderm while the remaining cells form ectoderm
WHAT PARTS OF THE DO THE 3 GERM LAYERS FORM
- Ectoderm
epidermis of skin - hair - brain - spinal cord
- Mesoderm
dermis of skin - muscle - bone - cartilage - blood - connective tissue
- Endoderm
digestive organs - lungs, bladder
WEEKS 3-4 - WHAT HAPPENS & HOW
Neurulation: formation of neural tube & neural crest from ectoderm.
lateral edges of ectoderm have migrated ventrally and fused together to form a tube like structure which is the body of the embryo
WHAT IS THE FATE OF THE NEURAL TUBE CELLS
WHAT IS THE FATE OF THE NEURAL CREST CELLS
tube cells develop into brain and spinal cord
crest cells are multipotent
- sensory neurons (DRG)
- craniofacial cartilage & bone
- adrenal medulla
- sympathetic neurons
- glia
WEEK 4 - WHAT HAPPENS
WHAT PARTS OF THE NEURAL TUBE FORM THE SENSORY INTERNEURONS AND MOTOR NEURONS
Neural tube cell growth and differentiation
Dorsal/Alar plate cells
- sensory interneurons in the dorsal horn
Ventral/Basal plate cells
- motor neurons in the ventral horn
WEEKS 4-5 - WHAT HAPPENS & HOW
Development of cerebral cortex and brain stem - grow from 3 vesicle stage to 5 vesicle stage
The cranial end of the neural tube is modified to form the cerebral cortex and brain stem
The cavity w/in the neural tube forms ventricles
The first stage of development is the formation of vesicles/ventricle or fluids filled swelling
LIST THE PARTS OF THE 3 VESICLE STAGE
Forebrain / prosencephalon
Midbrain / mesencephalon
Hindbrain / rhombencephalon
LIST THE PARTS OF THE 5 VESICLE STAGE
Telencephalon-cerebral hemisphere & lateral ventricle
Diencephalon-optic vesicle & 3rd ventricle
Mesencephalon - cerebral aqueduct
Metencephalon - 4th ventricle
Myelencephalon - 4th ventricle
WHAT HAPPENS AS THE HEAD DEVELOPS
Different parts of the brain and brain stem grow at different rates
such that
the cortex come to form a cap over the rest of the diencephalon & brain stem
1 (2)
NAME EACH OF THE 5 VESICLES & WHAT IS CONTAINED IN EACH OF THEM & THE SPINAL CORD
SPINAL CORD (2)
- Telencephalon: cerebral cortex - basal ganglia
- Diencephalon: retina - thalamus - hypothalamus
- Mesencephalon: midbrain - superior - Inf collicullus
- Metencephalon: pons - cerebellum
- Meyelencephalon: medulla
Spinal Cord: posterior horn - sensory
ventral horn - motor
SURFACE ANATOMY OF CORTEX
LOBES (4)
FISSURE (1)
SULCI (2)
GYRI (6)
Lobes: frontal / temporal / parietal / occipital
Fissure: lateral
Sulci: central / parieto-occipital
Gyri: precentral / postcentral / supramarginal / angular / superior temporal / inferior frontal lobe
WHAT ARE THE BRAIN STEM STRUCTURES
Midbrain
pons
medulla oblongata
WHAT ARE THE MAJOR STRUCTURES OF THE MIDBRAIN
- cerebral aqueduct
- superior colliculi
- substantia nigra
- crus cerebri
- 4th ventricle
- cranial nerve V
- corticospinal tract
- olive
- pyramid
- dorsal motor nucleus of vagus nerve
- ML
- carries CSF btw 3rd & 4th ventricles
- relay nucleus in the processing of visual information to control coordinated head & eye mvments
- has dopamine neurons involved in Parkinson’s disease
- has motor neuron axons for voluntary mvment of head and body
- contains CSF
- sensory info from face & motor to muscles of mastication
- has motor neuron axons for voluntary mvment of body
- relay nucleus to cerebellum involved in motor coordination
- condensed bundle of fibers of corticospinal tract
10.
- carries somatosensory axons from truck & limbs
WHAT ARE THE 4 VENTRICLES
RIGHT LATERAL VENTRICLE
LEFT LATERAL VENTRICLE
3RD VENTRICLE
4TH VENTRICLE
WHAT ARE THE 4 PARTS OF THE LATERAL VENTRICLE
- Frontal (anterior) horn
- Body
- Temporal (inferior) horn
- Occipital (posterior) horn
NAME TO THE OTHER 5 PARTS OF THE VENTRICULAR SYSTEM
- interventricular foramen of Monro - connects each lateral ventricle with the thrid ventricle
- cerebral aqueduct - connects 3rd & 4th ventricle
- Foramen of Luschka & Magende: openings in roof of 4th ventricle to allow CSF to move into subarachnoid space
- central canal
- atrium
WHAT SECRETS CSF
WHAT FORM DOES THE CSF COME FROM THIS STUCTURE
WHERE IS THE STRUCTURE FOUND
CHOROID PLEXUS
ULTRAFILTRATE OF PLASMA
LATERAL, 3RD, 4TH VENTRICLES
BRODMANN’S AREAS
more closely linked to physiological function than are specific anatomical gyri
WHAT ARE THE 3 CHARACTERISTICS OF CSF
- colorless
- 3% plasma proteins, glucose, ions (Na,Cl, K,Ca) but no RBCs/WBCs
- can be test for diagnosis of variety of neurological disease & infections
collect fluid by lumbar puncture
- pathological conditions result in changes in
color / presence of WBCs / changes in protein & glucose levels
WHAT IS THE PATH OF FLOW OF CSF (7)
LATERAL VENTRICLE
3RD VENTRICLE
CEREBRAL AQUEDUCT
4TH VENTRICLE
SUBARACHNOID SPACE
ARACHNOID GRANULATION (valve like)
VENOUS SINUS
WHAT ARE THE FUNCTIONS OF CSF (3)
- Protects against physical injury
shock absorber / supports brain b/c of its buoyancy
- Helps maintain a constant external environment for neurons and glial cells
- may also help remove byproducts of brain metabolism
