Snell - Blood Supply:Nervous Dev. Flashcards
- The following statements concern the blood supply to the brain:
A. The brain receives its blood supply directly from the two external carotid arteries.
B. The circle of Willis is formed by the anterior cerebral, the internal carotid, the posterior cerebral, the basilar, and the anterior and posterior communicating arteries.
C. The cerebral arteries do not anastomose on the surface of the brain.
D. There are numerous anastomoses between the branches of the cerebral arteries once they have entered the substance of the brain.
E. The main blood supply to the internal capsule is from the central branches of the anterior cerebral artery.
B. The circle of Willis is formed by the anterior cerebral, the internal carotid, the posterior cerebral, the basilar, and the anterior and posterior communicating arteries.
A. The brain receives its blood SUPPLY DIRECTLY AND INDIRECTLY from the TWO INTERNAL CAROTID AND THE TWO VERTEBRAL ARTERIES that lie within the subarachnoid space (see p. 475).
C. The cerebral arteries ANASTOMOSE on the surface of the brain (see p.483).
D. There are NO ANASTOMOSES between the branches of the cerebral arteries once they have entered the substance of the brain (see p. 483).
E. The main blood supply to the internal capsule is from the central branches of THE MIDDLE CEREBRAL ARTERY (see p. 479).
- The areas of the cerebral cortex listed below receive their arterial supply as indicated:
A. The precentral gyrus (face area is supplied by the middle cerebral artery.
B. The postcentral gyrus (face area) is supplied by the anterior cerebral artery.
C. The cuneus is supplied by the anterior cerebral artery.
D. The inferior temporal gyrus is supplied by the middle cerebral artery.
E. The Wernicke area is supplied by the posterior cerebral artery.
A. The precentral gyrus (face area is supplied by the middle cerebral artery
B. The face area of the postcentral gyrus is supplied by the MIDDLE cerebral artery
C. The cuneus is supplied by the POSTERIOR cerebral artery
D. The inferior temporal gyrus is supplied by the POSTERIOR cerebral artery
E. The Wernicke area is supplied by the MIDDLE cerebral artery.
- The arteries listed below arise from the main stem arteries as indicated:
A. The ophthalmic artery is a branch of the middle cerebral artery.
B. The pontine arteries are branches of the internal carotid artery.
C. The posterior communicating artery is a branch of the middle cerebral artery.
D. The posterior spinal artery arises from the vertebral artery.
E. The posterior inferior cerebellar artery is a branch of the basilar artery.
D. The posterior spinal artery arises from the vertebral artery
A. The ophthalmic artery is a branch of the cerebral portion of the INTERNAL CAROTID ARTERY
B. The pontine arteries are branches of the BASILAR ARTERY
C. The posterior communicating artery is a branch of the INTERNAL CAROTID ARTERY
E. The posterior inferior cerebellar artery is a branch of the VERTEBRAL ARTERY
- The veins listed below drain into the venous sinuses indicated:
A. The superior cerebral veins drain into the inferior sagittal sinus.
B. The great cerebral vein drains into the superior sagittal sinus.
C. The superior cerebellar veins drain only into the straight sinus.
D. The spinal veins drain into the external vertebral venous plexus.
E. The inferior sagittal sinus drains into the straightsinus.
E. The inferior sagittal sinus drains into the straight sinus (see Fig. 17-5).
A. The superior cerebral veins drain into the SUPERIOR sagittal sinus (see Fig. 17-5).
B. The great cerebral vein drains into the STRAIGHT sinus (see Fig. 17-5).
C. The superior cerebellar veins drain into the STRAIGHT SINUS, THE TRANSVERSE SINUS, AND THE OCCIPITAL SINUS
D. The spinal veins drain into the INTERNAL VERTEBRAL VENOUS PLEXUS
- The following statements concern the cerebral blood flow:
A. The sympathetic postganglionic fibers exert great control over the diameter of the cerebral blood vessels.
B. It varies greatly with changes in the general blood pressure.
C. Oxygen tension in the cerebral blood has no effect on the diameter of the cerebral blood vessels.
D. One of the most powerful vasodilators of cerebral blood vessels is carbon dioxide.
E. The blood flow for a particular area of nervous tissue following occlusion of a cerebral artery does not depend on the collateral circulation.
D . One of the most powerful vasodilators of cerebral blood vessels is carbon dioxide (see p. 481).
A. The sympathetic postganglionic fibers exert VERY LITTLE control over the diameter of the cerebral blood vessels (see p. 481).
B. The cerebral blood flow varies ONLY SLIGHTLY with changes in the general blood pressure (see
p. 481).
C. LOW oxygen tension in the cerebral blood CAUSES VASODILATION of the cerebral blood vessels
E. The blood flow for a particular area of nervous tissue following occlusion of a cerebral artery DEPENDS ON THE ADEQUACY of the collateral circulation (see p. 483).
- The following statements concern cerebral ischemia:
A. Atheromatous degeneration of a cerebral artery does not cause degeneration of the nerve cells in the avascular area due to the presence of cerebrospinal fluid.
B. Neuronal function ceases after the blood flow has stopped for about 10 seconds.
C. Irreversible cerebral damage starts to occur after the blood flow has ceased for about 4 minutes.
D. Shock occurring as the result of severe physical trauma does not result in cerebral ischemia.
E. Cooling of the patient’s body following a cerebrovascular accident speeds up cerebral degeneration.
C. Irreversible cerebral damage starts to occur after blood flow has ceased for about 4 minutes
A. Atheromatous degeneration of a cerebral artery MAY CAUSE degeneration of the nerve cells in the avascular area and proliferation of the microglial cells in the surrounding area
B. Neuronal function ceases after blood flow has stopped for about 1 MINUTE
D. Shock occurring as the result of severe physical trauma CAN RESULT in cerebra ischemia
E. Cooling of the patient’s body following a cerebrovascular accident SLOWS DOWN cerebral degeneration.
- The following statements concern the blood supply to the spinal cord:
A. The posterior spinal arteries supply the posterior third of the spinal cord.
B. The veins do not communicate with the veins of the brain and the venous sinuses.
C. The arteria radicularis magna (artery of Adamkiewicz) arises in the upper thoracic region from the arch of the aorta.
D. The anterior spinal artery is double but usually arises from one vertebral artery.
E. The spinal arteries are not reinforced by branches of local arteries.
A. The posterior spinal arteries supply the posterior third of the spinal cord (see p. 481).
B. The spinal cord veins COMMUNICATE with the veins of the brain and the venous sinuses (see p.482).
C. The arteria radicularis magna (artery of Adamkiewicz) arises from the aorta in the LOWER THORACIC OR UPPER LUMBAR vertebral levels
D. The anterior spinal artery is SINGLE but usually arises from BOTH vertebral arteries (see p. 482).
E. The spinal arteries are REINFORCED by RADICULAR ARTERIES, which are branches of local arteries (see p. 482).
- The following statements concern the neural tube:
A. It is lined by stratified squamous cells.
B. The neuroblasts migrate medially to form the intermediate zone.
C. The repeated division of the matrix cells does not increase the length and diameter of the tube.
D. The ventricular zone will form the gray matter of the spinal cord.
E. The nerve fibers in the marginal zone become myelinated and form the white matter of the spinal cord.
E . The nerve fibers in the marginal zone of the developing neural tube become myelinated and form the white matter of the spinal cord.
A. The wall of the neural tube is formed of a single layer OF PSEUDOSTRATIFIED COLUMNA epithelial cells (see Fig. 18-2).
B. The neuroblasts migrate PERIPHERALLY to form the intermediate zone (see Fig. 18-2).
C. The repeated division of the matrix cells of the neural tube results in an INCREASE in the length and diameter of the tube (see p. 502).
D. The INTERMEDIATE ZONE of the neural tube will form the gray matter of the spinal cord
- The following statements concern the neural crest cells:
A. They are formed from the medial margin of the neural plate.
B. They give rise to the posterior root ganglia.
C. They do not form the neurons of the autonomic ganglia.
D. The Schwann cells of peripheral nerves are not formed from neural crest cells.
E. They form the cells of the suprarenal cortex.
B. The neural crest cells give rise to the posterior root ganglia (see Fig. 18-1).
A. The neural crest cells are formed from the LATERAL MARGIN of the neural plate (see Fig. 18-1).
C. The neural crest cells FORM the neurons of the autonomic ganglia (see Fig. 18-1).
D. The Schwann cells of peripheral nerves are FORMED from neural crest cells (see Fig. 18-1).
E. The neural crest cells form the cells of the suprarenal MEDULLA (see Fig. 18-1).
- The following statements concern the developing spinal cord:
A. The alar plates form the neurons in the anterior gray columns.
B. The nerve cells of the sympathetic outflow are not formed from the basal plates.
C. In the adult, the lower end of the spinal cord lies at the level of the lower border of the first lumbar vertebra.
D. At birth, the lower end of the spinal cord lies at the level of the third sacral vertebra.
E. The meninges surrounding the spinal cord are developed from the endoderm.
C. In the adult, the lower end of the spinal cord lies at the level of the lower border of the first lumbar vertebra (see p. 504).
A. The alar plates form the neurons in the POSTERIOR gray columns (see p. 502).
B. The nerve cells of the sympathetic outflow are FORMED from the basal plates (see p. 502).
D. At birth, the lower end of the spinal cord lies at the level of the third LUMBAR vertebra (see p. 503).
E. The meninges of the spinal cord are developed from the MESENCHYME that surrounds the neural tube (see p. 503).
- The following statements concern the development of the brainstem:
A. The cerebellum is formed from the dorsal part of the alar plates of the metencephalon.
B. The neurons of the deep cerebellar nuclei are derived from the matrix cells lining the cavity of the midbrain vesicle.
C. The neuroblasts in the dorsal plates will form the nuclei of the trochlear and oculomotor nerves.
D. The neuroblasts of the superior and inferior colliculi are also formed from the neurocytes in the basal plates.
E. The pons arises from the alar part of the metencephalon with cellular contributions from the alar part of the myelencephalon.
A. The cerebellum is formed from the dorsal part of the alar plates of the metencephalon (see Fig.
18-7).
B. The neurons of the deep cerebellar nuclei are derived from the matrix cells lining the cavity of the HINDBRAIN vesicle (see p. 506).
C. The neuroblasts in the BASAL plates will form the nuclei of the trochlear and oculomotor nerves (see p. 507).
D. The neuroblasts of the superior and inferior colliculi are formed from the neurocytes in the ALAR PLATES (see Fig. 18-9).
E. The pons arises from the ANTERIOR PART of the metencephalon, with cellular contributions from the alar part of the myelencephalon (see p. 506).
- The following statements concern the fate of the forebrain vesicle:
A. The optic vesicle grows out of the midbrain vesicle.
B. The thalamus is formed from the alar plates in the medial walls of the diencephalon.
C. The lamina terminalis is formed from the rostral end of the diencephalon.
D. The pars nervosa of the hypophysis is formed from the floor of the diencephalon.
E. The hypothalamic nuclei are formed from the basal plates of the diencephalon.
D. The pars nervosa of the hypophysis cerebri is formed from the floor of the diencephalon (see
p. 509).
A. The optic vesicle grows out of the FOREBRAIN vesicle (see Fig. 18-4).
B. The thalamus is formed from the alar plates in the LATERAL walls of the diencephalon (see Fig. 18-12).
C. The lamina terminalis is formed from the rostral end of the TELENCEPHALON (see p. 509).
E. The hypothalamic nuclei are formed from the ALAR plates of the diencephalon (see p.509).
- The following statements concern the development of the cerebral hemispheres:
A. The corpus striatum is formed from the proliferation of the matrix cells lining the roof of the forebrain vesicle.
B. The interventricular foramen is formed by the cavity of the diencephalon.
C. The choroid plexus of the lateral ventricle is formed by vascular ectoderm covered by ependymal cells.
D. The internal capsule is formed by the developing ascending and descending tracts growing between the developing thalamus and caudate nucleus medially and the lentiform nucleus laterally.
E. The cortical neurons develop in situ and do not migrate out laterally from the matrix cells lining the cavity of the cerebral hemisphere.
D. The internal capsule is formed by the developing ascending and descending tracts growing between the developing thalamus and caudate nucleus medially and the lentiform nucleus laterally (see Fig.18-12).
A. The corpus striatum is formed from the proliferation of the matrix cells lining the FLOOR of the forebrain vesicle (see p. 511).
B. The interventricular fora-men is formed by the cavity of the TELENCEPHALON (see Fig. 18-12).
C. The choroid plexus of the lateral ventricle is formed by vascular MESENCHYME covered by ependymal cells (see p.509).
E. The neurons of the cerebral cortex develop from matrix cells lining the cavity of the cerebral hemisphere. These cells produce large numbers of neuroblasts that MIGRATE OUT into the marginal zone (see p. 512).
- The following statements concern the development of myelination in the brain:
A. Myelination begins at birth.
B. The sensory fibers are myelinated last.
C. The process of myelination is haphazard.
D. Myelination of the nerve tracts is largely complete by the fourth year of life.
E. Myelination is carried out by oligodendrocytes and not by neurons.
E. In the developing brain, myelination is carried out by oligodendrocytes and not by neurons (see p.512).
A. In the developing brain, myelination begins at about the SIXTH MONTH OF FETAL LIFE (see p. 512).
B. In the developing brain, the sensory fibers are myelinated FIRST (see p. 512).
C. Myelination of the nerve tracts is not haphazard but SYSTEMATIC, occurring in different nerve fibers at specific times (see p. 512).
D. Myelination of the nerve tracts is largely complete by the END OF THE SECOND YEAR (see p. 512).
- The following statements concern the condition of spina bifida:
A. It is one of the more common congenital anomalies of the central nervous system.
B. The most common form of spina bifida is syringomyelocele.
C. The condition occurs most often in the cervical and upper thoracic regions.
D. In a myelocele, the neural tube closes in the region of the defect.
E. Most cases of spina bifida occulta require explorative surgery.
A . Spina bifida is one of the more common congenital anomalies of the central nervous system see p. 512).
B. The most common form of spina bifida is SPINA BIFIDA OCCULTA (see Fig. 18-14).
C. Spina bifida occurs most often in the LOWER THORACIC, LUMBAR, AND SACRAL REGIONS (see p. 512).
D. In a myelocele, the neural tube FAILS TO CLOSE in the region of the defect (see Fig. 18-14).
E. Most cases of spina bifida occulta REQUIRE NO TREATMENT (see p. 512).
