NB1 Flashcards
What are neurons
Cells that transmit nerve impulses
What are glia
Non-neuronal cells in the central and peripheral nervous system that do not produce electrical impulses
What are microglia
Macrophages found in the brain and spinal cord
What consist of the central nervous system
Brain, brain stem, and spinal cord
What consist of the peripheral nervous system
All the nerves in the body that are found outside the spinal cord
What is the term for ribosomes in the cell body of a neurone
Nissl bodies
What is the term for cell body of a neurone
Perikaryon
Function of glial cells
-Provide structural support and myelin to the nervous system
Function of astrocytes
Provide structural support / blood brain barrier
Function of oligodendrocytes
Form myelin in central nervous system
Schwann cells in PNS
Function of ependymal cells
Line the ventricles and produce cerebrospinal fluid
Function of microglia
Macrophages of the brain (phagocytic)
Cells that give rise to brain tumours
Glial cells give rise to gliomas
What is the cerebrum
- Consist of right and left cerebral hemisphere
- Has 4 lobes : Frontal, Parietal, Occipital, Temporal
What is the brainstem
- Final part of brain before spinal cord begins
- Divided into 3 parts; (from top to bottom - Midbrain, Pons, Medulla)
What is the cerebellum
Posterior aspect of the brain/brainstem
What does the hindbrain consist of
Pons, Medulla, Cerebellum
What is grey matter
Neural tissue that is grey in colour and is comprised of neural cell bodies
What is white matter
Neural tissue that is white in colour and is compromised of myelinated axon
What is cortex
Outer layer of the cerebral hemispheres, composed of folds of grey matter
What is gyrus
Convex fold of grey matter (mountains)
What is sulcus
Concave folds of grey matter (valleys)
What does association fibres do
Interconnect cortical sites within one cerebral hemisphere
What does commissural fibres (corpus callosum) do
Run from one cerebral hemisphere to the other
What does projection fibres do
Pass from cerebral cortex to subcortical structures
Definition:
- ipsilateral
- contralateral
- decussate
- on the same side
- on the opposite side
- to switch from one side to another
What are cranial nerves
A set of 12 pairs of nerves that emerge directly from the brain
What are spinal nerves
Nerves that exit from the spinal cord (below brainstem)
Difference between afferent & efferent neurone
Afferent is a 3 neurone pathway while efferent is a 2 neurone pathway
Meningeal layers
Skin Bone -Dura mater -Arachnoid mater Subarachnoid space Trabeculae -Pia mater Blood vessel Cerebral cortex White matter
note: ‘-‘ are the actual meninges
What is pia mater (soft)
Very outer layer of brain tissue and intimately connected with the brain
What is arachnoid mater (spidery)
Thin, transparent tissue that covers brain specimen
Overlies sulcus
What is dura mater (hard)
Thick, fibrous connnective tissue associated with skull and form partitions between hemispheres
What does ectoderm, mesoderm and endoderm become
Ectoderm - all epidermis and nervous system
Mesoderm - bone, muscle, connective tissue and dermis
Endoderm - inner lining of GI tract; respiratory tract
Places in the embryonic disc that has ectoderm and endoderm only
- Oropharyngeal membrane - dissolves; anterior is stomodeum which give rise to mouth
- Cloacal membrane - posterior is proctodeum which gives rise to anus
What does neural crest cells contribute to
- Neurons and glial cells of the sensory, sympathetic and parasympathetic nervous system
- The epinephrine-producing (medulla) cells of the adrenal gland
- The pigment-containing cells of the epidermis
- Many of the skeletal and connective tissue components of the head
Describe zipping process
- Begins at day 22
- Tube close completely at the cranial end 3 or 4 days later and at the tail (caudal) end 2 to 3 days subsequently (day 27)
- Neurulation is complete - CNS is a closed tube - narrow caudal end = spinal cord
- Broader region at head region = brain
