Exam I - Structure Flashcards
Name the general order of neural development.
What structures arise from each: Forebrain (Prosencephalon), Midbrain (Mesencephalon), and Hindbrain (Rhombencephalon)?
Neural groove – neural tube, differentiation.
Forebrain (Prosencephalon) – Telencephalon, Diencephalon.
Midbrain (Mesencephalon)– Tectum, tegmentum.
Hindbrain (Rhombencephalon) - Cerebellum, pons, medulla.
Describethe embryo’s – 3 distinct layers of cells (germ layers).
The entire nervous system arises from? Cell bodies in PNS arise from?
germ layers: Endoderm - viscera . Mesoderm - bones, muscle. Ectoderm- skin, nervous system. Neural tube –Entire nervous system. Neural Crest-Cell bodies in PNS.
Primary Neurulation?
Notochord – forms from? When? Why is it important?
Primary Neurulation – process by which neural plate becomes neural tube, brain and spinal cord to lumbar level.
Notochord – forms from mesoderm at about 16 days post fertilization – Notochord is important for induction (causes overlying ectoderm to form neural plate).
Describe neural dev. between days 18-26 post-fertilization.
Neural folds form day 18. Neural folds contact day 20 Zipper-like from cervical levels. Secondary Neuralation also begins. Anterior neuropore – day 24. Posterior neuropore – day 26. Secondary Neurulation Sacral and coccygeal Levels of spinal cord Begins day 20 - 42
Secondary Neurulation? When does it begin and end?
Secondary Neurulation - Sacral and coccygeal
Levels of spinal cord
Begins day 20 - 42.
Dysgraphic or Neural Tube Defects –defined as what?
____failure to close results in anencephly (no brain) or cleft palette.
____ failure to close results in spina bifida.
Defects during _____result in loss of sensation to leg/feet and bladder control.
Dysgraphic or Neural Tube Defects – Congenital defects from malformations during early development.
Anterior neuropore: Failure to close results in anencephly (no brain).
Posterior neuropore: Failure to close results in spina bifida.
Secondary Neurulation defects result in loss of sensation
to leg/feet and bladder control.
Describe the 4 Imp. Parts of the First Phase of Differentiation.
Cellular proliferation and migration in second trimester, continue until term.
First Phase of Differentiation:
1. Primary Vesicle formation.
2. Rostral end of neural tube - Forms entire brain.
3. 3 vesicles (about 6 weeks).
4. Encephalon – “Brain” formation begins. Prosencephalon (forebrain).
Mesencephalon (midbrain).
Rhombencephalon (hindbrain).
The optic nerve and retina develop from the ___? Describe their development.
Develop from the prosencephalon.
Optic vesicles sprout to become the optic stalk and optic cups which ultimately becomes optic nerve and retina
Five major parts of prosencephalon differentiation?
- Telencephalon (end brain)– two cerebral hemispheres .
- Vesicles sprout off the ventral surface – olfactory bulbs.
- Cells of the telencephalon differentiate.
- White matter system develops.
- Optic vesicles sprout to become the optic stalk and optic cups which ultimately becomes optic nerve and retina.
Telencephalon - becomes the Cerebral Cortex and Basal Telencephalon, which includes what structures?
Diencephalon – between brain, becomes what?
Ventricles – what are they? where do each arise from?
Describe the 3 systems of white matter.
Telencephalon - Cerebral Cortex and Basal Telencephalon – hippocampus, amygdala, basal ganglia.
Diencephalon – between brain - Thalamus, Epithalamus and Hypothalamus.
Ventricles – fluid-filled space. lateral ventricles, (telencephalon), 3rd ventricle (diencephalon).
White Matter – 3 systems:
Cortical White Matter - cerebral cortex.
Corpus Callosum – connects hemispheres, communication between them.
Internal Capsule – facilitates communication between cortex w/ diencephalon and brainstem.
Structures of the mesencephalon: Dorsal surface is the? Ventral surface is the? Describe the kind of info passes through the midbrain. Tectum differentiates into ? Tegmentum differentiates into?
Structures of the mesencephalon:
Dorsal surface - tectum .
Ventral surface - tegmentum.
Sensory information passes through – as well as nuclei (groups) of neurons that control movement, contribute to sensory information.
Tectum differentiates into superior and inferior colliculus - visual and auditory processing.
Tegmentum – substania nigra and red nucleus – control movement.
Structures of the hindbrain: Metencephalon includes what structures? Myencephalon includes what? \_\_\_\_ grow to form the cerebellum. Most motor axons from the cortex synapse where? And then subsequently project to where?
Structures of the hindbrain –
Pons and Cerebellum - Metencephalon.
Medulla oblongata - Myencephalon.
Rhombic lips grow to form the cerebellum
Most motor axons from the cortex synapse in pons and project to cerebellum.
Caudal hindbrain differentiation:
Motor axons (efferents) from the cortex cross (decussate) where?
Medulla is used for what?
Caudal hindbrain: Motor axons (efferents) from the cortex cross (decussate) in medullary pyramids.
Medulla - Somatic sensory relay, autonomic sensory and motor nuclei.
Spinal cord differentiates into what major structures? (8)
Caudal Neural Tube. Gray Matter – Neurons (dorsal and ventral horns). Dorsal Horns – sensory . Ventral Horns – motor. White Matter – Axons Dorsal Columns - carry somatic information up spinal cord to medulla where it crosses. Lateral Columns – corticospinal tract. Ventral Columns.
Function/makeup of each spinal component? Caudal Neural Tube. Gray Matter. Dorsal Horns . Ventral Horns . White Matter. Dorsal Columns . Lateral Columns. Ventral Columns.
Caudal Neural Tube. Gray Matter – Neurons (dorsal and ventral horns). Dorsal Horns – sensory . Ventral Horns – motor. White Matter – Axons Dorsal Columns - carry somatic information up spinal cord to medulla where it crosses. Lateral Columns – corticospinal tract. Ventral Columns.
