A3 - Embryology (Mitchell) Flashcards
Envelops CNS axon
Plasma membrane of oligodendrocyte
Rostral neuropore closes
Day 25
Folding begins here
6th somite
Flexure where brain meets spinal cord
Cervical flexure
Caudal 1/3 neural tube
Spinal cord
Gives rise to:
Thalami, etc.
Diencephalon
Gives rise to:
Lower part of 4th ventricle
Myelencephalon
Responsible for:
Consciousness
Sensorimotor transformation
Sensory integration
Planning
Telencephalon
Envelops peripheral axon
Cell body of neurolemma (schwann cell)
Embryonic cell layer continuous with early CNS
Surface ectoderm
Development of neural tube
4th week
Wrappings lose cytoplasm
Oligodendrocyte
Suci and gyri develop in the human brain at this age
9 months
Gives rise to:
Telencephalon
Diencephalon
Forebrain (Prosencephalon)
Gives rise to:
Lateral ventricles
Telencephalon
Major relay center for hearing and vision
Midbrain (Mesencephalon)
Flexure where the pons develops
Pontine flexure
Oligodendrocytes are derivatives of _________
Neuroepithelium
Gives rise to:
Aqueduct
Mesencephalon
Alar neurons migrate to marginal zone, responsible for:
Fine touch proprioception
- Gracile & Cuneate nucleii
Cerebellum develops as an expansion of _____
alar plates
Cells that help absorb & produce CSF in central canal & ventricles
Ependymal cells
Produces CSF
Choroid plexus
Surrounds neuroectoderm
Mesenchyme
4th Somite
Spinal cord development
Membranous layer of CNS derived from neural crest
Arachnoid mater
Changes in reflexes in adolescents due to
Myelination
Wrappings retain cytoplasm
Neurolemma (schwann cell)
Portion of the pituitary gland that grows from the roof of the mouth
Anterior hypophysial diverticulum
Gives rise to:
Medulla
Myelencephalon
Neurolemma (schwann cells) derived from _________
Neural crest cells
Layer that contains axons
Marginal layer
Gives rise to:
Mesencephalon
Midbrain – actually is the mesencephalon
In the rostral myelencaphalon, motor nucleii are located _____ while sensory nucleii are located _____
medially
laterally
Gives rise to:
Pons
Cerebellum
Metencephalon
Layer that contains neuronal bodies
Mantle layer
Portion of the pituitary gland that is an outgrowth of the hypothalamus
Posterior neural hypophysial diverticulum
Gives whitish appearance to white matter
Myelin sheath
Myelination of CNS axons
Oligodendrocytes
Transmits signal from sensory neuron axon to somatic motor neuron
Association neuron
Can wrap up to 50 axons
Oligodendrocytes
Layer that becomes gray matter
Mantle layer
Gives rise to:
Upper part of 4th ventricle
Metencephalon
Canal within the neural tube becomes
Central canal
Gives rise to:
Cerebral hemispheres
Telecephalon
Location of sensory neurons
Outside CNS - dorsal root ganglia
Forms brain and spinal cord
Neural tube
Integrates sensory input to fine tune motor output
Cerebellum
Caudal neuropore closes
Day 27
Motor or sensory fibers myelinated first?
Motor
Myelination of peripheral axons
Neurolemma (schwann cells)
Flexure between forebrain & midbrain
Midbrain flexure
Cranial 2/3 neural tube
Brain
Divides alar and basal plates
Sulcus limitans
Relay station for sensory neurons
Alar plates
Gives rise to:
Metencephalon
Myelencephalon
Hindbrain (Rhombencephalon)
Cells that provide support throughout CNS
Glial cells
Formed from ependymal cells and overlying pia
Choroid plexus
Layer that becomes white matter
marginal layer
Walls of neural tube become
Spinal cord
Relay information to and from cerebral cortex
Regulates basic functions - sleep, thirs, alertness
Diencephalon
- Thalamic structures
Provides path for regeneration of peripheral nerves
Myelin sheath
Sensory neurons are derived from _______
Neural crest cells
Contains motor neurons
Basal plate
Layer that lines the central canal
Ventricular (ependymal)
Gives rise to:
3rd ventricle
Diencephalon
Closure of neuropores drives _________
Vascularization of CNS