Lecture 2 Structure of the Nervous System Flashcards
Horizontal Section
- A slice through the brain parallel to the ground
Sagittal Section
- A slice through the brain parallel to the neuraxis and perpendicular to the ground
Midsagittal
- The plane through the neurosis perpendicular to the ground - Divides the brain into two symmetrical halves
Meninges
- The three layers of tissue that encase the central nervous system - The dura mater, arachnoid membrane, and the pia mater
Dura Mater
- The outermost of the meninges - Tough and flexible
Arachnoid Membrane
- From the greek Arachne, meaning “spider” - The middle layer of the meninges, located between the dura mater and the inner pia mater
Pia Mater
- The layer of the meninges adjacent to the surface of the brain; thin and delicate
Subarachnoid Space
- The fluid-filled space that cushions the brain - Located between the arachnoid membrane and the pia mater
Cerebrospinal Fluid
- A clear fluid, similar to blood plasma, that fills the ventricular system of the brain and the subarachnoid space surrounding the brain and spinal cord
Layers (surface to CNS)
- Dura mater - Arachnoid Membrane - Subarachnoid Space (blood vessels & Cerebrospinal fluid CSF)) - Pia Mater - CNS Tissue
Ventricular System and production of cerebrospinal fluid
- Ventricles (little bellies) - 4 hollow spaces located inside the brain - Each ventricle produces CSF - CSF supports the weight of the brain - Help reduce shock to the CNS caused by sudden head movements - Brain contains about 125 ml of CSF - Half life of CSF is about 3 hours - All CSF is replaced every six hours by the choroid plexus
Development of the CNS
- CNS development begins 18 days after conception - Neural tube develops by twenty-first day to give rise to the brain and spinal cord - Neural tube closes at day 28 & forms the ventricles, forebrain, midbrain, & hindbrain
Asymmetrical division
- Division of a founder cell that gives rise to another founder cell and a neuron, which migrates away from the ventricular zone towards its final resting place in the brain
Apoptosis (literally, a “falling away”)
- Death of a cell caused by a chemical signal that activates a genetic mechanism inside the cell
Forebrain
- The most rostral of the three major divisions of the brain; includes the telencephalon and diencephalon
Cerebral hemisphere
- One of the two major portions of the forebrain, covered by the cerebral cortex
Subcortical region
- The region located within the brain, beneath the critical surface - Contains the limbic system and the basal ganglia
Sulcus
- A groove in the surface of the cerebral hemisphere, smaller than a fissure
Fissure
- A major groove in the surface of the brain, larger than a sulcus
Gyrus
- A convolution of the cortex of the cerebral hemispheres, separated by sulk or fissures
Primary visual cortex
- The region of the posterior occipital lobe whose primary input is from the visual system
Calcarine fissure
- A fissure located in the occipital lobe on the medial surface of the brain; most of the primary visual cortex is located along its upper and lower banks
Primary auditory cortex
- The region of the superior temporal lobe whose primary input is from the auditory system
Lateral fissure
- The fissure that separates the temporal lobe from the overlying frontal and parietal lobes
Primary somatosensory cortex
- The region of the anterior parietal lobe whose primary input is from the somatosensory system
Central sulcus
- The sulcus that separates the frontal lobe from the parietal lobe
Primary motor cortex
- The region of the posterior frontal lobe that contains neurons that control movements of skeletal muscle - The connections of this region are contralateral - The left primary motor cortex controls the right side of the body and vice versa
Frontal Lobe
- The anterior portion of the cerebral cortex, rostral to the parietal lobe and dorsal to the temporal lobe. This includes everything in front of the central sulcus
Parietal lobe
- The region of the cerebral cortex caudal to the frontal lobe and dorsal to the temporal lobe
Temporal Lobe
- The region of the cerebral cortex rostral to the occipital lobe and ventral to the parietal and frontal lobes
Occipital lobe
- The region of the cerebral cortex caudal to the parietal and temporal lobes. This is located posterior to the central sulcus
Sensory Association Cortex
- Those regions of the cerebral cortex that receive information from regions of the primary sensory cortex. Perception takes place here and memories are stored here
Motor Association Cortex (Premotor Cortex)
- The region of the frontal lobe rostral to the primary cortex; also known as the premotor cortex. Controls overall motor behavior
Prefrontal Cortex
- The region of the frontal lobe rostral to the motor association cortex. This region is involved in formulating plans and strategies
Corpus Callosum
- A large bundle of axons that interconnects corresponding regions of the association cortex on each side of the brain
Neocortex
- The phylogenetically newest cortex, including the primary sensory cortex, primary motor cortex, and association cortex
Limbic Cortex
- Phylogenetically old cortex, located at the medial edge of the cerebral hemispheres; part of the limbic system
Cingulate gyrus
- A strip of limbic cortex lying along the lateral walls of the groove separating the cerebral hemispheres, just above the corpus callosum
Limbic system
- A group of brain regions including the anterior thalamic nuclei, amygdala, hippocampus, limbic cortex, and parts of the hypothalamus, as well as their interconnecting fiber bundles
Hippocampus
- A forebrain structure of the temporal lobe, constituting an important part of the limbic system; includes the hippocampus proper, dentate gyrus, and subiculum
Amygdala
- A structure in the interior of the rostral temporal lobe, containing a set of nuclei
Fornix
- A fiber bundle that connects the hippocampus with other parts of the brain, including the mammillary bodies of the hypothalamus
Mammillary bodies
- A protrusion of the bottom of the brain at the posterior end of the hypothalamus, containing some hypothalamic nuclei - Serve as relay stations in reflexes related to the sense of smell
Basal ganglia
- Part of the telencephalon, including the caudate nucleus, the globes plaids, and the putamen - Parkinson’s disease is caused by degeneration of the caudate nucleus and putamen - Parkinson’s disease includes weakness, tremors, rigidity of the limbs, poor balance and difficulty initiating movements
Thalamus ( Greek thalamus, “inner chamber”)
- The largest portion of the diencephalon, located above the hypothalamus; contains nuclei that project information to specific regions of the cerebral cortex and receive information from it.
Projection fiber
- An axon of a neuron in one region of the brain whose terminals form synapses with neurons in another region
Hypothalamus
- A group of nuclei in the diencephalon situated beneath the thalamus - Controls the autonomic nervous system - Controls the anterior and posterior pituitary glands - Organizes behavior such as fighting, feeding, fleeing, and mating
Hypothalamus- Optic chiasm
- A connection between the optic nerves where half of the fibers of the optic nerve cross to the contralateral side
Hypothalamus- Anterior pituitary gland
- The “master gland” - The anterior part of the pituitary gland; an endocrine gland whose secretions are controlled by the hypothalamic hormones
Hypothalamus- Neurosecretory cell
- A neuron that secretes a hormone or hormone-like substance
Hypothalamus - Posterior pituitary gland
- The posterior part of the pituitary gland; an endocrine gland that contains hormone-secreting terminal buttons of axons whose cell bodies lie within the hypothalamus
Hindbrain-metencephalon Hindbrain
- The most caudal part of the brain; includes the mesencephalon and myelencephalon
Hindbrain-metencephalon Cerebellum (little brain)
- A major part of the brain located dorsal to the pons, containing the two cerebellar hemispheres, covered with the cerebellar cortex; important component of the motor system
Hindbrain-metencephalon Cerebellar peduncle
- One of three bundles of axons that attach each cerebellar hemisphere to the dorsal pons
Hindbrain-metencephalon Pons (‘bridge’)
- The region of the metencephalon rostral to the medulla, caudal to the midbrain, and ventral to the cerebellum; appears to be important in sleep and arousal
Hindbrain-metencephalon Medulla oblongata
- The most caudal portion of the brain, located in the mylencephalon, immediately rostral to the spinal cord - Includes nuclei that control vital functions such as the cardiovascular system, respiration, and skeletal muscle tone.
Spinal Cord
- The cord of nervous tissue that extends caudally from the medulla
Spinal root
- A bundle of axons surrounded by connective tissue that occur in pairs, which fuse and form a spinal nerve
Spinal Cord Dorsal Root
- The spinal root that contains incoming (afferent) sensory fibers
Spinal Cord Ventral root
- The spinal root that contains the outgoing (efferent) motor fibers
Spinal Nerves
- A peripheral nerve attached to the spinal cord
Spinal Nerves Afferent axon
- An axon directed toward the CNS, conveying sensory information
Spinal Nerves Dorsal root ganglion
- A nodule on a dorsal root that contains cell bodies of afferent spinal nerve neurons
Spinal Nerves Efferent Axon
- An axon directed away from the CNS, conveying motor commands to muscles and glands
Cranial Nerves
- Twelve pairs of peripheral nerves attached directly to the brain that serve sensory & motor functions of the head, neck, and shoulders
Cranial Nerves Vagus Nerve ( “wandering”)
- The largest of the cranial nerves, conveying efferent fibers of the parasympathetic division of the autonomic nervous system to organs of the thoracic and abdominal cavities
ANS Somatic nervous system
- The part of the peripheral nervous system that controls the movement of skeletal muscles or transmits somatosensory information to the CNS
Autonomic nervous system
- The portion of the peripheral nervous system that controls the body’s vegetative functions
ANS Sympathetic division
- The portion of the ANS that controls functions that accompany arousal and expenditure of energy
ANS Sympathetic ganglia
- Nodules that contain synapses between preganglionic and postganglionic neurons of the sympathetic nervous system
ANS - Sympathetic Preganglionic neuron
- The efferent neuron of the ANS whose cell body is located in a cranial nerve nucleus or in the intermediate horn of the spinal gray matter and whose terminal buttons synapse upon postganglionic neurons in the ANS
ANS - Sympathetic Postganglionic neuron
- Neurons of the ANS that form synapses directly with their target organ
ANS - Sympathetic Adrenal medulla
- The inner portion of the adrenal gland, located atop the kidney, controlled by sympathetic nerve fibers; secretes epinephrine and norepinephrine
ANS Parasympathetic Division
- The portion of the ANS that controls functions that occur during a relaxed state. - Supports activities involved with increases in the body’s supply of stored energy including salivation, gastric and intestinal motility, secretion of digestive juices, and increased blood flow to the gastrointestinal system
Reversed Prompt
- A slice through the brain parallel to the ground
Horizontal Section
Reversed Prompt
- A slice through the brain parallel to the neuraxis and perpendicular to the ground
Sagittal Section
Reversed Prompt
- The plane through the neurosis perpendicular to the ground - Divides the brain into two symmetrical halves
Midsagittal
Reversed Prompt
- The three layers of tissue that encase the central nervous system - The dura mater, arachnoid membrane, and the pia mater
Meninges
Reversed Prompt
- The outermost of the meninges - Tough and flexible
Dura Mater
Reversed Prompt
- From the greek Arachne, meaning “spider” - The middle layer of the meninges, located between the dura mater and the inner pia mater
Arachnoid Membrane
Reversed Prompt
- The layer of the meninges adjacent to the surface of the brain; thin and delicate
Pia Mater
Reversed Prompt
- The fluid-filled space that cushions the brain - Located between the arachnoid membrane and the pia mater
Subarachnoid Space
Reversed Prompt
- A clear fluid, similar to blood plasma, that fills the ventricular system of the brain and the subarachnoid space surrounding the brain and spinal cord
Cerebrospinal Fluid
Reversed Prompt
- Dura mater - Arachnoid Membrane - Subarachnoid Space (blood vessels & Cerebrospinal fluid CSF)) - Pia Mater - CNS Tissue
Layers (surface to CNS)
Reversed Prompt
- Ventricles (little bellies) - 4 hollow spaces located inside the brain - Each ventricle produces CSF - CSF supports the weight of the brain - Help reduce shock to the CNS caused by sudden head movements - Brain contains about 125 ml of CSF - Half life of CSF is about 3 hours - All CSF is replaced every six hours by the choroid plexus
Ventricular System and production of cerebrospinal fluid
Reversed Prompt
- CNS development begins 18 days after conception - Neural tube develops by twenty-first day to give rise to the brain and spinal cord - Neural tube closes at day 28 & forms the ventricles, forebrain, midbrain, & hindbrain
Development of the CNS
Reversed Prompt
- Division of a founder cell that gives rise to another founder cell and a neuron, which migrates away from the ventricular zone towards its final resting place in the brain
Asymmetrical division
Reversed Prompt
- Death of a cell caused by a chemical signal that activates a genetic mechanism inside the cell
Apoptosis (literally, a “falling away”)
Reversed Prompt
- The most rostral of the three major divisions of the brain; includes the telencephalon and diencephalon
Forebrain
Reversed Prompt
- One of the two major portions of the forebrain, covered by the cerebral cortex
Cerebral hemisphere
Reversed Prompt
- The region located within the brain, beneath the critical surface - Contains the limbic system and the basal ganglia
Subcortical region
Reversed Prompt
- A groove in the surface of the cerebral hemisphere, smaller than a fissure
Sulcus
Reversed Prompt
- A major groove in the surface of the brain, larger than a sulcus
Fissure
Reversed Prompt
- A convolution of the cortex of the cerebral hemispheres, separated by sulk or fissures
Gyrus
Reversed Prompt
- The region of the posterior occipital lobe whose primary input is from the visual system
Primary visual cortex
Reversed Prompt
- A fissure located in the occipital lobe on the medial surface of the brain; most of the primary visual cortex is located along its upper and lower banks
Calcarine fissure
Reversed Prompt
- The region of the superior temporal lobe whose primary input is from the auditory system
Primary auditory cortex
Reversed Prompt
- The fissure that separates the temporal lobe from the overlying frontal and parietal lobes
Lateral fissure
Reversed Prompt
- The region of the anterior parietal lobe whose primary input is from the somatosensory system
Primary somatosensory cortex
Reversed Prompt
- The sulcus that separates the frontal lobe from the parietal lobe
Central sulcus
Reversed Prompt
- The region of the posterior frontal lobe that contains neurons that control movements of skeletal muscle - The connections of this region are contralateral - The left primary motor cortex controls the right side of the body and vice versa
Primary motor cortex
Reversed Prompt
- The anterior portion of the cerebral cortex, rostral to the parietal lobe and dorsal to the temporal lobe. This includes everything in front of the central sulcus
Frontal Lobe
Reversed Prompt
- The region of the cerebral cortex caudal to the frontal lobe and dorsal to the temporal lobe
Parietal lobe
Reversed Prompt
- The region of the cerebral cortex rostral to the occipital lobe and ventral to the parietal and frontal lobes
Temporal Lobe
Reversed Prompt
- The region of the cerebral cortex caudal to the parietal and temporal lobes. This is located posterior to the central sulcus
Occipital lobe
Reversed Prompt
- Those regions of the cerebral cortex that receive information from regions of the primary sensory cortex. Perception takes place here and memories are stored here
Sensory Association Cortex
Reversed Prompt
- The region of the frontal lobe rostral to the primary cortex; also known as the premotor cortex. Controls overall motor behavior
Motor Association Cortex (Premotor Cortex)
Reversed Prompt
- The region of the frontal lobe rostral to the motor association cortex. This region is involved in formulating plans and strategies
Prefrontal Cortex
Reversed Prompt
- A large bundle of axons that interconnects corresponding regions of the association cortex on each side of the brain
Corpus Callosum
Reversed Prompt
- The phylogenetically newest cortex, including the primary sensory cortex, primary motor cortex, and association cortex
Neocortex
Reversed Prompt
- Phylogenetically old cortex, located at the medial edge of the cerebral hemispheres; part of the limbic system
Limbic Cortex
Reversed Prompt
- A strip of limbic cortex lying along the lateral walls of the groove separating the cerebral hemispheres, just above the corpus callosum
Cingulate gyrus
Reversed Prompt
- A group of brain regions including the anterior thalamic nuclei, amygdala, hippocampus, limbic cortex, and parts of the hypothalamus, as well as their interconnecting fiber bundles
Limbic system
Reversed Prompt
- A forebrain structure of the temporal lobe, constituting an important part of the limbic system; includes the hippocampus proper, dentate gyrus, and subiculum
Hippocampus
Reversed Prompt
- A structure in the interior of the rostral temporal lobe, containing a set of nuclei
Amygdala
Reversed Prompt
- A fiber bundle that connects the hippocampus with other parts of the brain, including the mammillary bodies of the hypothalamus
Fornix
Reversed Prompt
- A protrusion of the bottom of the brain at the posterior end of the hypothalamus, containing some hypothalamic nuclei - Serve as relay stations in reflexes related to the sense of smell
Mammillary bodies
Reversed Prompt
- Part of the telencephalon, including the caudate nucleus, the globes plaids, and the putamen - Parkinson’s disease is caused by degeneration of the caudate nucleus and putamen - Parkinson’s disease includes weakness, tremors, rigidity of the limbs, poor balance and difficulty initiating movements
Basal ganglia
Reversed Prompt
- The largest portion of the diencephalon, located above the hypothalamus; contains nuclei that project information to specific regions of the cerebral cortex and receive information from it.
Thalamus ( Greek thalamus, “inner chamber”)
Reversed Prompt
- An axon of a neuron in one region of the brain whose terminals form synapses with neurons in another region
Projection fiber
Reversed Prompt
- A group of nuclei in the diencephalon situated beneath the thalamus - Controls the autonomic nervous system - Controls the anterior and posterior pituitary glands - Organizes behavior such as fighting, feeding, fleeing, and mating
Hypothalamus
Reversed Prompt
- A connection between the optic nerves where half of the fibers of the optic nerve cross to the contralateral side
Hypothalamus- Optic chiasm
Reversed Prompt
- The “master gland” - The anterior part of the pituitary gland; an endocrine gland whose secretions are controlled by the hypothalamic hormones
Hypothalamus- Anterior pituitary gland
Reversed Prompt
- A neuron that secretes a hormone or hormone-like substance
Hypothalamus- Neurosecretory cell
Reversed Prompt
- The posterior part of the pituitary gland; an endocrine gland that contains hormone-secreting terminal buttons of axons whose cell bodies lie within the hypothalamus
Hypothalamus - Posterior pituitary gland
Reversed Prompt
- The most caudal part of the brain; includes the mesencephalon and myelencephalon
Hindbrain-metencephalon Hindbrain
Reversed Prompt
- A major part of the brain located dorsal to the pons, containing the two cerebellar hemispheres, covered with the cerebellar cortex; important component of the motor system
Hindbrain-metencephalon Cerebellum (little brain)
Reversed Prompt
- One of three bundles of axons that attach each cerebellar hemisphere to the dorsal pons
Hindbrain-metencephalon Cerebellar peduncle
Reversed Prompt
- The region of the metencephalon rostral to the medulla, caudal to the midbrain, and ventral to the cerebellum; appears to be important in sleep and arousal
Hindbrain-metencephalon Pons (‘bridge’)
Reversed Prompt
- The most caudal portion of the brain, located in the mylencephalon, immediately rostral to the spinal cord - Includes nuclei that control vital functions such as the cardiovascular system, respiration, and skeletal muscle tone.
Hindbrain-metencephalon Medulla oblongata
Reversed Prompt
- The cord of nervous tissue that extends caudally from the medulla
Spinal Cord
Reversed Prompt
- A bundle of axons surrounded by connective tissue that occur in pairs, which fuse and form a spinal nerve
Spinal root
Reversed Prompt
- The spinal root that contains incoming (afferent) sensory fibers
Spinal Cord Dorsal Root
Reversed Prompt
- The spinal root that contains the outgoing (efferent) motor fibers
Spinal Cord Ventral root
Reversed Prompt
- A peripheral nerve attached to the spinal cord
Spinal Nerves
Reversed Prompt
- An axon directed toward the CNS, conveying sensory information
Spinal Nerves Afferent axon
Reversed Prompt
- A nodule on a dorsal root that contains cell bodies of afferent spinal nerve neurons
Spinal Nerves Dorsal root ganglion
Reversed Prompt
- An axon directed away from the CNS, conveying motor commands to muscles and glands
Spinal Nerves Efferent Axon
Reversed Prompt
- Twelve pairs of peripheral nerves attached directly to the brain that serve sensory & motor functions of the head, neck, and shoulders
Cranial Nerves
Reversed Prompt
- The largest of the cranial nerves, conveying efferent fibers of the parasympathetic division of the autonomic nervous system to organs of the thoracic and abdominal cavities
Cranial Nerves Vagus Nerve ( “wandering”)
Reversed Prompt
- The part of the peripheral nervous system that controls the movement of skeletal muscles or transmits somatosensory information to the CNS
ANS Somatic nervous system
Reversed Prompt
- The portion of the peripheral nervous system that controls the body’s vegetative functions
Autonomic nervous system
Reversed Prompt
- The portion of the ANS that controls functions that accompany arousal and expenditure of energy
ANS Sympathetic division
Reversed Prompt
- Nodules that contain synapses between preganglionic and postganglionic neurons of the sympathetic nervous system
ANS Sympathetic ganglia
Reversed Prompt
- The efferent neuron of the ANS whose cell body is located in a cranial nerve nucleus or in the intermediate horn of the spinal gray matter and whose terminal buttons synapse upon postganglionic neurons in the ANS
ANS - Sympathetic Preganglionic neuron
Reversed Prompt
- Neurons of the ANS that form synapses directly with their target organ
ANS - Sympathetic Postganglionic neuron
Reversed Prompt
- The inner portion of the adrenal gland, located atop the kidney, controlled by sympathetic nerve fibers; secretes epinephrine and norepinephrine
ANS - Sympathetic Adrenal medulla
Reversed Prompt
- The portion of the ANS that controls functions that occur during a relaxed state. - Supports activities involved with increases in the body’s supply of stored energy including salivation, gastric and intestinal motility, secretion of digestive juices, and increased blood flow to the gastrointestinal system
ANS Parasympathetic Division