CNS Embryogenesis- Reynolds Flashcards
What is the difference between somatic and visceral?
Somatic- innervates skin and skeletal muscle
Visceral- (autonomic) innervates smooth muscle; sympathetic and parasympathetic
Which part closes first on the neural tube: cranial or caudal?
Caudal
Name the primary CNS segments
Prosencephalon
Mesencephalon
Rhombencephalon
Name the corresponding structures for :
Prosencephalon
Mesencephalon
Rhombencephalon
Prosencephalon- Forebrain
Mesencephalon- Midbrain
Phombencephalon- Hindbrain
What does the Prosencephalon split into?
Telencephalon
Diencephalon
Name the corresponding structures for the Telencephalon and the Diencephalon
Telencephalon - Cerebral Hemispheres
Diencephalon - eyes, pituitary, hypothalamus, thymus
What does the Mesencephalon split into?
Nothing; does not split
Name the corresponding structures for the Mesencephalon
Cerebral aqueduct
What does the Rhombencephalon split into?
Metencephalon
Myelencephalon
Name the corresponding structures for the Metencephalon and the Myelencephalon
Metencephalon - cerebellum and the pons
Myelencephalon - medulla oblongata
What is neurite outgrowth?
When neurons test the environment with filopodia
What is hydrocephalus?
When there is too much “water” or cerebral spinal fluid in the brain because of the cerebral aquaduct doesnt function correctly
What do the pons do?
Relay signals between the spinal cord and the cortex
What does the cerebellum do?
Center for balance and posture
What does the medulla oblongata do/
Control center for respiration, heart beat, reflex movements and other functions
Describe how peripheral neurons form
Neuroblasts - make up motor neurons from the basal plate
Neural crest cells extend peripherally (cranial) to form dendrites and dorsally to form axons- makes up the sensory neurons
Interneurons form to make the connection between sensory and motor
What is Hirschsprung’s Disease?
Neural crest cells do not migrate properly towards the gut
What is stabilization in terms of neurons?
The interaction between neuron and target tissue determines connection type and how many
Describe the migration of a neural crest cell
Becomes a mesenchymal cell (SEM)
Loses cell adhesion and gains integrins
What are the three main divisions of the neural crest?
Cranial - cells migrate before the neural tube closes
Circumpharyngeal- marks pathways for two groups
Trunk - cells migrate after the neural tube closes
What does the cranial neural crest give rise to?
Skin, bones, and cartilage in the face
What does the circumpharyngeal neural crest give rise to?
Vagal- Gut
Cardiac- vessels of the heart
What does the trunk neural crest give rise to?
Dorsolateral- melanocytes
Ventrolateral- sensory ganglia
Ventral- adrenal chromaffin
What does the central nervous system consist of?
Brain and spinal cord
What does the peripheral nervous system consist of?
Sensory and Motor
Describe sensory, motor, and interneurons
Sensory- goes from the receptor to the CNS
Motor- goes from the CNS to the receptor
Interneuron- goes inbetween sensory and motor in the spinal cord
What is the function of neuroglial cells?
Provide nutrients
Support
Forms myelin
Has a role in transmission
What are the three integral parts of a synapse?
Presynaptic neuron
Synaptic cleft
Postsynaptic neuron
Where are graded potentials located?
Dendrites
Where are action potentials located?
Axon Hillock and Axon
Describe astrocytes
Glial cells of the CNS
Help with the blood brain barrier
Describe oligodendrocytes
Glial cells of the CNS
Multi-myelinate axons
Describe microglia
Glial cells of the CNS
Immune phagocytic cells
Describe ependymal
Glial cells of the CNS
Cuboidal cells that secrete cerebral spinal fluid
Describe schwann cells
Glial cells of the PNS
Single- myelinate axons
Describe satellite cells
Glial cells of the PNS
Surrounds neuronal cells and provides support
Which is faster conduction: myelinated or unmyelinated?
Myelinated
Which is faster conduction: large or small diameter?
Large
What are the three PNS CT coverings?
Endoneurium
Perineurium
Epineurium
What are the three layers of menigial CT?
Dura mater (tough mother) Arachinoid (spiders) Pia mater (tender mother)
“The tough mother squashed the spider before it got to the wimpy mother”
What are ganglia?
A gang of neurons
