Chapter 3: Strucure Of The Nervous System Flashcards
Brain
Neurons, glia, and other supporting cells and floats in pool of cerebrospinal fluid
Cerebrospinal Fluid
Clear fluid, similar to brain plasma that fills ventricular system of the brain and subarachnoid space surrounding brain and spinal cord
Neuroaxis
Imaginary line drawn through center of length of CNS, from bottom of spinal cord to front of forebrain
Rostral
“Toward the beak”
Front of face
Anterior
Located near or toward the head
Medial
Toward middle of body, away from side
Dorsal
“Toward of back”
Toward top of head or back
Perpendicular to neuroaxis
Caudal
“Toward the tail”
Away from front of face
Posterior
Located near or toward the tail
Ventral
“Toward the belly”
Bottom of skull or front surface of the body
Lateral
Toward side of body, away from middle
Ipsilateral
Located on the same side of the body
Contralateral
Located on opposite side of body
Cerebral Cortex
Outermost later of gray matter of cerebral hemispheres
3 ways of slice human nervous system
- Coronal
- Parallel
- Perpendicular
Coronal
Cut to middle to divide brain into front and back halves
- Frontal Sections
Frontal Sections
Slice through Brian parallel to forehead
Parallel sections
Cut to divide brain into top half and bottom half
- Horizontal Section
Horizontal Sections
Slice through brain parallel to ground
Perpendicular sections
Aka sagital section
- Midsagittal plane
Sagital section
Slice through brain parallel to neuroaxis and perpendicular to ground
Midsaggital Plane
Divides brain into two symmetrical left and right halves
3 layers of meninges in CNS
- Dura mater
- Arachnoid membrane
- Pia mater
Dura mater
Outermost of meninges
Tough and flexible
Arachnoid Membrane
Middle later of meninges, located between outer dura mater and inner pia mater
Pia mater
Layer of meninges that clings to surface of brain
Thin and delicate
Subarachnoid Space
Fluid-filled space that cushions brain
- in between arachnoid membrane and pia mater
PNS meninges
Only has dura mater and pia mater
Ventricle
One of hollow spaces within the brain, filled with CSF
Lateral Ventricle
One of two ventricles located in center of telencephalon
Third Ventricle
Ventricle located in center of diencephalon
Massa Intermedia
Bridge of neural tissue that crosses through middle of third ventricle
Cerebral Aqueduct
Narrow tube interconnecting third and fourth ventricles of brain, located in center of mesencephalon
Fourth Ventricle
Ventricle located between cerebellum and dorsal pons, in centerof metencephalon
CSF is made up of […]
Choroid plexus
Choroid plexus
Highly vascular tissue that protrudes into ventricles and produces CSF
Arachnoid Granulation
Small projections of arachnoid membrane through dura mater into superior sagital sinus
Forebrain
Lateral: Telencephalon: Cerebral Cortex, Basal Ganglia, Limbic System
Third: Diencephalon: Thalamus, Hypothalamus
Midbrain
Cerebral Aqueduct: Mesencephalon: tectum, tegmentum
Hindbrain
Fourth: Metencephalon: Cerebellum, pons
Fourth: Myelencephalon: medulla oblongata
Cerebral Cortex
Surrounds cerebral hemispheres; aka gray matter
- primary visual cortex, primary auditory cortex, primary somatosensory cortex
Basal ganglia
Group of subcortical nuclei in telencephalon, caudate nucleus, globus pallidus, and putamen
- importnat parts of motor system
Limbic System
Group of brain regions including anterior thalamic nuclei, amygdala, hippocampus, limbic cortex, and parts of hypothalamus, as well as their interconnecting fiber bundles
- also consists of fornix and mammillary bodies
Fornix
Connects hippocampus with other parts of brain
Thalamus
Contains nuclei that project specific info to specific regions of cerebral cortex and receive info from it
- lateral geniculate nucleus, medial geniculate nucleus, and ventrolateral nucleus
Hypothalamus
Involved in regulations of ANS, control of anterior and posterior pituitary glands and integration of species- typical behaviors
- right behind optic chiasm
Tectum
Includes superior colliculi (visual system) and inferior colliculi (auditory system)
Tegmentum
Includes nuclei controlling eye movements, PAG (pain sensation), red nucleus, substantia nigra, VTA and reticular formation
Cerebellum
Covered by cerebellar cortex and has set of deep cerebellar nuclei
- receive projections from cerebellar cortex and send projections out of cerebellum to other parts of brain
- attached to dorsal surface of pons by superior, middle, and inferior cerebellar peduncles
- integrates info and modifies motor outflow
Pons
Important in sleep and arousal
- relays info from cerebral cortex to cerebellum
Medulla Oblongata
Contains part of reticular formation, incliding nuclei that control vital function such as regulation of cardiovascular system, respiration, and skeletal muscle tone
Cerebral Hemisphere
One of two major portions of forebrain, covered by cerbral cortex
Cerebrum
Consists of two cerbral hemispheres
Subcortical Regions
Regions located within brain, beneath cortical surface
Sulcus
Groove in surface of cerebral hemisphere, smaller than fissure
Fissure
Major groove in surface of brain, longer than sulcus
Gyrus
Convolution of cortex of cerebral hemispheres, separated by sulci or fissures
Calcarine Fissure
Fissure in occipital lobe on medial surface of brain
- most of the primary visual cortex is located along its upper and lower banks
Lateral Fissure
Fissure that separates temporal lobe from overlying frontal and parietal lobes
Central Sulcus
Sulcus that separates frontal lobe from parietal lobe
Insular Cortex
Sunken region of cerebral cortex that is normally covered by rostral superior temporal lobe and caudal inferior frontal lobe
- Sensory info and emotinal valence
Sensory Assocaition Cortex
Regions of cerebral cortex that receive info from regions of primary sensory cortex
Motor Association Cortex
Region of frontal lobe rostral to primary motor cortex
Prefrontal Cortex
Region of frontal lobe rostral to motor association cortex
Nucleus
Identifiable group of neural cell bodies in CNS
Lateral Geniculate Nucleus
Receives fibers from retina and projects fibers to primary visual cortex
Medial Geniculate Nucleus
Recieves fibers from auditory system and projects fibers to primary auditory cortex
Ventrolateral Nucleus
Nucleus of thalamus that receives input from cerebellum and sends axons to primary motor cortex
Anterior Pituitary Gland
Endocrine gland whose secretions are controlled by hypothalamic hormones
Neurosecretary Cell
Neuron that secretes hormone or hormone-like substance
Posterior Pituitary Gland
Endocrine gland that contained hormone-secreting terminal buttons of axons whose cell bodies lie within hypothalamus
- produces and secretes oxytocin and vasopressin
Reticular Formation
Large network of neural tissue located in central region of brain stem
Periaqueductal Gray
Surrounds cerebral aqueduct
- contains neural circuits involved in species- typical behaviors
Red Nucleus
Receives input from cerebellum and motor cortex and sends axons to motor neurons in spinal cord
Substantia Nigra
Darkly stained region of tegmentum that contains neurons that communicate with caudate nucleus and putamen in basal ganglia
Spinal Cord
Composed of vertal column with 24 individual vertebrae and spinal roots
Dorsal Root
Spinal root that contains incoming (afferent) sensory fibers
- larger than ventral root
Ventral Root
Spinal root that contains outgoing (efferent) motor fibers
Spinal Root
Bundle of axons surrounded by connective tissue that occurs in pairs, which fuse and form spinal nerve
Cauda Equina
Bundle of spinal roots located caudal to end of spinal cord
Caudal Block
Anesthesia and paralysis of lower part of body produced by injection of local anesthetic into CSF surrounding cauda equina
Cranial Nerves
Peripheral nerves attach directly to brain
- 12 pairs
Ex. Vagus nerve
Olfactory Bulb
Protrusion at end of olfactory nerve
- receives input from olfactory receptors
Spinal Nerve
Peripheral nerve attached to spinal cord
- nerves leave the vertebral column and travel to the muscles or sensory receptors they innervate (or supply), branching repeatedly as they go
Afferent Axon
Axon directed toward CNS, conveying senory info
Dorsal Root Ganglion
Nodule on dorsal root that contains cell bodies of afferent spinal nerve neurons
Efferent Axon
Axon directed away from CNS, conveying motor commands to muscles and glands
Somatic Nervous System
Part of PNS that controls movement of skeletal muscles or transmits somatosensory info to CNS
Autonomic Nervous System
Portion of PNS that controls body’s vegetative functions
Sympathetic Division
Portion of ANS that controls functions that accompany arousal and expenditure of energy
Sympathetic Ganglia
Nodules that contain synapses between preganglionic and postganglionic neurons of sympathetic nervous system
Sympathetic Ganglion Chain
One pair of groups of sympathetic ganglia that lie ventrolateral to vertebral column
Preganglionic Neuron
Efferent neuron of ANS whose cell body is located in cranial nerve nucleus or immediate horn of spinal gray matter and whose terminrla buttons synapse upon postganglionic neurons in autonomic ganglia
Postganglionic Neuron
Neurons of ANS that form synapses directly with target organ
Parasympathetic Division
Portion of ANS that controls functions that occur during relaxed state
The brain floats in a bath of […] within the […]
The brain floats in a bath of CSF within the subarachnoid space
Frontal Lobe
anterior portion of the cerebral cortex, rostral to parietal lobe and dorsal to the temporal lobe
Parietal Lobe
the region of the cerebral cortex caudal to the frontal lobe and dorsal to the temporal lobe
Temporal Lobe
region of the cerebral cortex rostral to the occipital lobe and ventral to the parietal and frontal lobes
Occipital Lobe
region of cerebral cortex causal to the parietal and temporal lobes
Sensory Cortex
Telencephalon: primary visual cortex, primary auditory cortex, primary somatosensory cortex
Primary Visual Cortex
receives visual information
- region of posterior occipital lobe whose primary input is from the visual system
Primary Auditory Cortex
receives auditory information
- the region of the superior temporal lobe whose primary input is from the auditory system
Primary Somatosensory Cortex
receives information from the body senses except olfaction and gustation
- the region of the anterior parietal lobe whose primary input is from the somatosensory system
Lateralization in the Cerebral Cortex
some functions of cerebral hemispheres are lateralized
- Left: analyzes info - Right: synthesizes info
Tentorium
tent-shaped duplicated fold of meningeal dura
Superior Colliculi
protrusions on top of the midbrain
- part of visual system
Inferior Colliculi
protrusions on top of the midbrain
- part of auditory system
Vagus Nerve
regulates functions of organs in the thoracic and abdominal cavities