DB - neuroanatomy week 1 Flashcards
What is hypomyelination?
Diminished amounts of myelin sheath
What is dysmyelination?
Disorders resulting in malformations or defects in the myelin sheath.
What is demyelination?
Disorders causing damage to pre-existing normal myelin.
What is the function of general somatic afferent nerves?
Touch, temperature and pain from non-visceral structures.
What is the function of general somatic efferent nerves?
Motor to skeletal muscles.
What is the function of general visceral afferent nerves?
Distension, touch, temperature and pain from visceral structures.
What is the function of general visceral efferent nerves?
Motor to viscera, smooth muscles and glands.
What is the function of special somatic afferent nerves?
Vision, hearing and balance.
Innervated by the optic nerve.
What is the function of special visceral afferent nerves?
Taste and olfaction.
Innervated by the facial and glossopharyngeal nerve.
What is the function of special visceral efferent nerves?
Innervates the branchial arches.
Embryological regions within the head and neck that causes skeletal muscle to grow.
What is the difference between funiculi and fasciculi?
Funiculi - white matter in the spinal cord.
Fasciculi - Axons of the same origin, destination and function.
What structures are derived from the forebrain (prosencephalon)?
Telencephalon - cerebral hemispheres and basal nuclei.
Lumen: lateral ventricle, which is found between the cerebral hemispheres.
Diencephalon - thalamus, hypothalamus.
Lumen: 3rd ventricle, which is found between the thalamus and hypothalamus.
What structures are derived from the midbrain (mesencephalon)?
Tectus - roof
Tegmentum - floor
Cerebral aqueduct, which allows the flow of CSF.
What structures are derived from the hindbrain (rhombencephalon)?
Metencephalon - pons and cerebellum
Myelencephalon - medulla oblongata
Lumen: 4th ventricle
What is the embryological cause of spina bifida?
Failure of the caudal neuropore to close.
Surrounding tissues fail to meet and fuse.
Nervous tissue can be exposed and is only protected by skin and subcutaneous tissue.
What is the embryological cause of a dermoid sinus?
Neuroectoderm tissue fails to detach from normal ectoderm.
Resembles a tube down the cervical and thoracic regions of the back.
Sometimes there is communication between the skin and spine.
What is the embryological cause of anencephaly?
Failure of the rostral neuropore to close.
Forebrain structures fail to form and this is not compatible with life.
What is the significance of the ratio of the size of the cerebrum to the cerebellum?
The smaller the ratio of cerebrum to cerebellum, the more complicated the gait cycle.
Where is the lateral horn of the grey matter situated?
In the thoracolumbar regions. It contains sympathetic nerve bodies.
What are the functional areas of the cortex?
Frontal lobe - motor cortex
Parietal lobe - somatosensory cortex
Temporal lobe - olfactory and auditory cortex
Occipital lobe - visual cortex
Why is there a cranial shift of the spinal cord segments?
The spinal cord grows at a much faster rate than the vertebrae.
What is the main blood supply to the rostral portion of the brain via the circle of Willis?
Internal carotid artery
What is the main blood supply to the caudal portion of the brain via the circle of Willis?
Vertebral arteries anastomose to form the basilar artery.
Which artery of the circle of Willis supplies the medial hemisphere?
Rostral cerebral artery