| meninges | three membranous layers |
| dura mater | strong, white fibrous tissue, outer layer of meninges and inner periosteum of the cranial bones |
| arachnoid mater | delicate, spiderweb like layer between the dura mater and the Pia mater |
| pia mater | innermost, transpartents layers, adhere to the outer surface of the brain and spinal cord, and contains blood vessels |
| film terminale | blends with dura mater to form a fibrous cord that disappears into the periosteum of the coccyx |
| epidural space | located between the dura mater and inside the bony covering of the spinal cord, contains a supporting cushion of fat and other connective tissues |
| subdural space | located between the dura mater and the arachnoid mater, this contains lubercating serous fluid |
| subarachnoid space | located between the arachnoid and Pia mater, contains a significant amount of cerebrospinal fluid (CSF) |
| epidural hematoma | lucid intervals of consciousness with slowly deteriorating neurological signs (middle meningeal artery) |
| subdural hematoma | loss of consciousness that could be fluctuating with dizziness and headaches (venous tears) |
| subarachnoid hematoma | immediate rapid onset, LOC, headache, confusion, nausea (10-15% fatal) |
| CSF function | support and protective cushion, reservoir of circulating fluid, which is monitored by the brain to detect changes in the internal environment |
| CSF | found in the subarachnoid space around the brain and spinal cord and within the cavities and canals of the brain and spinal cord |
| ventricles | fluid-filled spaces within the brain |
| first and second ventricles | lateral- first and second, they are located in each hemisphere of the cerebrum |
| fothird ventricle | thin, vertical pocket of fluid below and medial to the later ventricles |
| fourth ventricle | tiny, diamond shaped space where the cerebrum attaches to the back of the brainstem |
| cerebrospinal fluid | occurs by separation of fluid from the blood in the choroid plexuses form the fourth ventricle, fluid goes to two different areas |
| arachnoid villi | fluid circulates in the subarachnoid space and then is absorbed into venous blood |
| structure of the spinal cord | within the spinal cavity and extends from the foramen magnum to the lower border of L1
tow bulges, one in the cervical region and one in the lumbar region
anterior median fissure and posterior median sulcus are two deep grooves, anterior fissure is deeper and wider |
| nerve roots | fibres of the dorsal nerve root
carry sensory info into the spinal canal |
| dorsal root ganglion | cell bodies of unipolar, sensory neurons make up a small region of grey matter in the dorsal nerve root |
| ventral nerve root | carry motor info out of the spinal cord
cell bodies of multipolar, motor neurone are in the grey matter of the spinal cord |
| spinal nerve | a single mixed nerve on each side of the spinal cord where the dorsal and ventral nerve roots join together |
| cauda equina | bundle of nerve roots extending from the conus medullar is (inferior end of the spinal cord) |
| grey matter | extends the length of the spinal cord, consists predominantly of cell bodies of interneurons and motor neurone
in transverse section, it look like an H with the limbs being called the anterior, posterior, and lateral horns of the grey matter- crossbar of the H is the grey COMMISSURE |
| white matter | surrounds the grey matter and is subdivided in each half |
| ascending tracts | conduct impulses UP the cord and to the brain |
| descending tracts | conduct impulses DOWN the cord from the brain |
| lateral spinothalamic | tracts- crude touch, pain, and temp |
| anterior spinothalamic | tracts- crude touch, pressure |
| fascicule gracilis and cuneatus | discriminating touch and conscious kinaesthesia |
| spinocerebellar | tracts- subconscious kinaesthesia |
| spinotectal | touch related to visual reflexes |
| lateral corticospinal | voluntary movements on opposite sides of the body |
| anterior corticospinal | voluntary movements on the same side of the body |
| reticulospinal | maintains posture during movement |
| rubrospinal | transmits impulses that coordinate body movements and maintenance of posture |
| tectospinal | head and neck movements during visual reflexes |
| vestibulospinal | coordination of posture and balance |
| the brain | largest organ, weighs 1.4 kg |
| medulla oblongata | lowest part of the brainstem, attaches to the spinal cord located above the foramen magnum
composed of white matter and a network of grey and white matter called the reticular formation network |
| pyramids | two bulges of white matter located on the ventral side of the medulla, formed by fibres of the pyramidal tracts |
| medulla | olive and nuclei |
| medulla: olive | oval projection located in the reticular formation |
| medulla: nuclei | clusters of neurone cell bodies located in the reticular formation |
| pons | located above the medulla and below the midbrain, composed of white matter and reticular formation |
| midbrain | located above the pons and below the cerebrum, forms the midsection of the brain
composed of white tracts and reticular formation
extending divergently through the midbrain and cerebral peduncles |
| corpora quadrigemina | landmark in midbrain, composed of two inferior colliculi and two superior colliculi
forms the posterior, upper part of the midbrain that lies just above the cerebellum |
| inferior colliculus | contains auditory centres |
| superior colliculus | contains visual centres |
| red nucleus and substantial nigra | clusters of cell bodies or neurone involved in muscular control |
| functions of the brain | sensory, motor and reflex functions |
| spinothalamic | important sensory tracts that pass through the brainstem |
| fascicule cuneatus and gracillis and spinoreticular | sensory tracts who's axons terminate in the grey matter of the brainstem |
| corticospinal and reticulospinal | two major tracts present in the white matter of the brainstem |
| nuclei in medulla | cardiac, vasomotor, and respiratory centres, also controls vomitting, coughing, sneezing etc |
| pons | contains reflexes mediated by fifth, sixth, seventh, and eighth |
| midbrain | contains centres for certain cranial nerve reflexes |
| structure of the cerebellum | second largest part of the brain, contains more neurone than the rest of the nervous system
located just below the posterior portion of the cerebrum
grey matter is on the outside, white is on the inside
has a lot of sluice, and parallel gyre (folia) |
| arbor vitae | internal white matter of the cerebellum, distinctive pattern similar to the veins of a leaf |
| white mater (short tracts) | conduct impulses from neurone cell bodies located in the cerebellar cortex to neurone who's dendrites and cell bodies compose nuclei located in the interior of the cerebellum |
| white matter (long tracts) | conduct impulses to and from the cerebellum fibres enter or leave by way of three pairs of penducles |
| inferior cerebellar peduncles | composed chiefly of tracts into the cerebellum from the medulla and cord |
| middle cerebellar peduncles | composed almost entirely of tracts into the cerebellum from the pons |
| superior cerebellar peduncles | compared principally of tracts from dentate nuclei in the cerebellum through the red nucleus of the midbrain to the thalamus |
| dentate nuclei | located in each hemisphere, nuclei is connected with thalamus and with motor arms of the cerebral cortex by tracts by means of the tracts, cerebellar impulses influence the motor cortex, and the motor cortex influences the cerebellum |
| functions of the cerebellum | compares motor commands of the cerebrum with the info coming from the proprioceptors in the muscle
impulses travel from the cerebellum to both the cerebrum ad muscles to coordination the intended action |
| functions of the cerebellum | produces skilled movements, controls skeletal muscles to maintain balance, controls posture, processes sensory info |
| diencephalon | located between the cerebrum and the midbrain, consists of several structures located around the third ventricle: thalamus, hypothalamus, optic chiasma, pineal gland, and others |
| thalamus | dumbbells shaped mass of grey matter, serves as a major relay station for sensory impulses on their way to cerebral cortex, plays a role in emotions by associating sensory impulses with feeling of good or bad |
| hypothalamus | beneath the thalamus, crucial part of regulating appetite, maintains body temp |
| infundibulum | the stalk leading to the post lobe of pit gland, small, performs functions for survival and enjoyments, links body and mind, links nervous system to endocrine system |
| pineal gland | located above the corpora quadrigemina of the midbrain, regulates the bodies biological clock produces melatonin |
| cerebral cortex | largest uppermost division of the brain, consists of the right and left cerebral hemisphere and is made up of six layers of grey matter |
| longitudinal fissure | deepest fissure and it divides cerebrum into two hemispheres |
| central sulcus | groove between frontal and parietal lobes |
| cerebral tracts | make up cerebrums white matter |
| projection tracts | extensions of the sensory spinothaamic tracts and motor corticospinal tracts |
| speciation tracts | most numerous cerebral tracts, extend from one convolution to another in the same hemisphere |
| commissural tracts | extend from one to convolution to a corresponding conviction in the other hemisphere, compose the croups callous and the anterior posterior commissures |
| basal nuclei | islands of great matter located deep inside the white matter of each hemisphere including: caudate nucleus, lentiform nucleus, amygdaloid nuclei |
| basal nuclei function | regulation of voluntary (conscious) motor control related to posture, walking, and other repetitive movements, possible roles in thinking and learning |
| precentral gyrus | somatic motor area, impulses from neurone in this area descend over motor tracts and stimulate skeletal muscles |
| postcentral gyrus | general somatic sensory area, receives impulses from receptors active by heat, cold and touch stimuli |
| transverve gyrus | auditory area |
| occipital lobe | primary visual area |
| consciousness | state of awareness of ones self, environments, and other humans |
| reticular activating system | functions as the arousal system for the cerebral cortex, it is crucial for maintaining consciousness |
| emotions | subject to experiencing and objective expressing of emotions involve functioning of the limbic system |
| limbic system | "emotional brain" located on the medial surface of the cerebrum, they have primary connections with other parts of the brain like the thalamus, fornix, septal nuclei, amygdaloid nucleus, and hypothalamus |
| memory | capable of storing and retrieving both short and long term memory
temporal, parietal, occipital lobes are response for short and long term memory |
| primary sensory neurons | conduct impulses from the periphery to the central nervous system |
| secondary sensory neurons | conduct impulses form the cord or brainstem to the thalamus
dendrites and cells dies are located in the grey matter of the cord and brainstem |
| tertiary sensory neurons | conduct impulses from thalamus to the postcenrral gyrus of the parietal lobe, bundle of axons of tertiary sensory neurone from the thalamocortical tracts, emend though the internal capsule to the cerebral cortex |
| medial lemniscal system | tracts that make up the fascicule cuneatus and gracilis and the medial lemniscus, axons of secondary sensory neurone make up medial lemniscus, it transmits imputes that produce discriminating touch and pressure sensations and kinaesthesia |
| spinothalamic pathway functions | pain, temp and crude touch |
| principal of the final common path | the motor neurone from the anterior grey horn of the spinal cord, conducts impulses to skeletal muscles |
| pyramidal tracts | located on the opposite side of the spinal cord in the later white column, 3 quarters of the fibres deviate in the medulla and extend down the cord, and one quarter of the fibres do not decussate but they do extend down the same side as they came |
| exrapyramidal - in the brain | relays motor neurone between the basal nuclei, thalamus, cerebellum, and brainstem |
