TSM1.3 - Development of the CNS and PNS Flashcards
What is the main function of the post-central gyrus?
It is the somatosensory cortex of the brain.
What is neurulation and when does it begin?
Neurulation is the formation of the neural plate and begins in the 3rd week of development.
What is grey matter primarily composed of?
Neuron cell bodies.
What is white matter primarily composed of?
Myelinated axons.
What is the basal ganglia involved in?
The basal ganglia is involved in motor activity.
What are nuclei?
Nuclei are a collection of cell bodies that lie deep within the brain.
What are the main derivatives of the neural plate?
The main derivatives of the neural plate are Dorsal Root Ganglia, melanocytes and Schwann cells.
Fusion of the neural tube begins in which region? And how does it proceed?
Fusion of the neural tube begins in the cervical region and proceeds in caudal and cephalic directions.
How does the cavity of the cranial tube stay in communication with the amniotic cavity?
Through the cranial and caudal neuropores.
When does the cranial neuropore close?
At the 18-20 somite stage (or 25th day).
When does the caudal neuropore close?
2 days after the cranial neuropore closes.
What does the failure of closure of neural pores cause?
Neural tube defects (NTDs).
What protein has increased levels with the neural tube defects?
Maternal Alpha feto-protein.
How can neural tube defects (NTDs) be detected?
Via ultrasound.
What are the three primary brain vesicles present by the 4th week of development?
The forebrain, the midbrain and the hindbrain.
By the fifth week of development the five secondary brain vesicles have developed. What are their names?
Telencephalon, diencephalon, mesencephalon, metencephalon and myelencephalon.
What secondary brain vesicle(s) does the forebrain develop into?
The telencephalon and the diencephalon
What secondary brain vesicle(s) does the midbrain develop into?
Mesencephalon.
What secondary brain vesicle(s) does the hindbrain develop into?
The metencephalon and the myelencephalon.
What adult brain structure does the telencephalon develop into?
The cortex.
What adult brain structure does the Diencephalon develop into?
The hypothalamus, thalamus and the pituitary gland.
What adult brain structure does the metencephalon develop into?
The pons and the cerebellum.
What adult brain structure does the myelencephalon develop into?
The medulla.
At which week of development does the surface of the growing brain begin to fold into sulci and gyri?
15 weeks.
How is the grey matter in the spinal cord organised?
A pair of basal (ventral) lamina, a pair of alar (dorsal) lamina and the sulcus limitans
What is the sulcus limitans?
The border between the basal and alar plates.
What does the basal lamina form?
The motor areas of the spinal cord and brain stem.
What does the alar lamina form?
The sensory areas of the brain stem and spinal cord.
How many cranial nerves does the PNS contain?
12
How many spinal nerves does the PNS contain?
31
From which cells do skeletal motor neurons and preganglionic autonomic neurons in the CNS develop?
From cells of the neural tube.
From which cells do sensory neurons and postganglionic autonomic neurons in the PNS develop?
Neural crest cells.
What connects the third and fourth ventricles?
The cerebral aqueduct.
Where is the fourth ventricle located?
In the hindbrain.
