HUBS 191 progress test 2 study guide with complete solution, Updated 2024

HUBS 191 progress test 2 study guide with complete solution, Updated 2024 central nervous system nervous system consisting of brain and spinal cord peripheral nervous system nervous system consisting of peripheral nerves glia 'glue' provide support for neurons, 5 type, 4 in CNS, 1 in PNS neurons nerve cells, transmission of information dendrites recieve input, send info into cell body cell body contains nucleus and organelles axon carries electrical impulses, may/may not be myelinated axon terminals end terminus of the axon, neuro transmitter release tract bundle of axons in the CNS grey matter group of cell bodies in cerebral cortex/spinal cord white matter bundle of axons in cerebral cortex/spinal cord ganglion group of cell bodies in PNS nerve bundle of axons in PNS input zone dendrites and cell body, receives chemical signals from other neurons summation zone axon hillock, decides to transmit signal or not conduction zone axon may be quite long, carry electrical signals between brain areas to and from spinal cord or to and from peripheral sensory receptors output zone axon terminals, contact input of other neurons, release of neuro transmitter multipolar multiple processes emanate from the cell body, the 'typical' neuron bipolar 2 processes emanate from the cell body (axon and long bridge to dendrites unipolar 1 process emanates from cell body (hangs on side of axon) anaxonic no distinct axon, all processes look alike astrocytes supply nutrients to neuron, ensheath blood capillaries, transmit information, CNS microglia immune cells of the CNS, engulf micro organisms / debris ependymal cells line fluid filled spaces of brain and spinal cord, have cillia to circulate CSF, CNS oligodentrocytes support nerve fibres, ensheath them with myelin, CNS schwann cells support peripheral nerve fibres, ensheath them with myelin, similar to oligodendrocytes, PNS myelin sheath lipid wrapped around axon, increases conduction velocity, multiple schwann cells in a row form the myelin sheath, gaps between myelin called nodes of ranivier Synapse/Synpatic Cleft neuro transmitter release from one axon terminals where electrical turns to chemical afferent information going into the brain efferent information out of brain flow of information info comes through receptors, afferent nerves, into CNS, integration/coordination, motor efferent (somatic or autonomic) somatic the stuff we are aware of and have control over somatic afferent sensory information of what we are aware of somatic efferent voluntary muscle control, 2 neurons between brain and effector, upper and lower motor neuron upper motor neuron cell body in brain, axon in spinal cord lower motor neuron cell body in spinal cord, axon in spinal nerve neuro-muscular junction Where neuron releases neurotransmitters (ACh) that depolarize muscle fiber cells - contraction autonomic involuntary control, 3 neurons between brain and effector, 2 divisions, sympathetic and parasympathetic autonomic neuron 1 cell body in brain, axon in brain or spinal cord (CNS) autonomic neuron 2 cell body in brain or spinal cord, axon in PNS , myelinated, neurotransmitter = ACh autonomic neuron 3 cell body in PNS, axon in PNS, unmyelinated, neurotransmitter = NE autonomic neurons effectors smooth muscle, cardiac muscle, glands, adipose/fat tissue autonomic ganglion area where synapse can occur in PNS sympathetic autonomic nervous system prepares body for acute/stress response, inc. HR, blood flow, pupil size, sweating, neruon 2 axon is short, neuron 3 axon is long exit from CNS parasympathetic autonomic nervous system prepares body for restful situations, opposite responses to sympathetic, neuron 2 axon long, neuron 3 axon short sympathetic chain ganglion where the preganglionic neurons synapse onto post ganglionic neurons resting membrane potential -70mV high conc. K+ inside, high conc Na+ outside action potential resting membrane - depolarzation - activation of sodium ion channels - rapid depolarization - inactivation of sodium ion channels/activation of potassium ion channels- potassium ions channels close when very hyperpolarized - both shut and pump restores voltage threshold action potential must exceed axon hillock for it to be propagated, must exceed -60mV (once threshold is exceeded it will continue to depolarize to +30mV before re polarization) synaptic transmission chemical binds to protein site (ACh) opening gates for protons to flow through chemically gated channels in NMJ graded depolarization chemical stimulus opens sodium ion channel, stimulus is removed and excess Na+ transported out of cytosol, chemical stimulus opens K+ ion channels, chemical stimulus removed foramen magnum A large opening at the base of the skull through which the brain connects to the spinal cord spinal cord starts at foramen magnum, finished inferior to border of first lumbar vertebra (conus medularis) inside meningeal sack which fits inside spinal cavity, filum terminale anchors spinal cord conus medularis non neural cone shaped ending to the spinal cord filum terminale fibrous non neural tissue tethering spinal cord to end of spinal cavity coccygeal tail bone/where the filum terminale anchors spinal cord segments 31 segments, 8 cervical, 12 thoracic, 5 lumbar, 5 sacral, 1 coccygeal, each has a pair of spinal nerves nerves from L1 or below must travel down to exit, called the cauda equina cauda equina collection of spinal nerves below the end of the spinal cord sulcus furrow fissure deep sulcus direction of information into CNS on dorsal aspect to spinal cord, out of CNS on ventral aspect (axons are myelinated) outwards flow info leaves spinal cord through ventral roots, somatic cell bodies in ventral horn, autonomic cell bodies in lateral horn inwards flow cell bodies of sensory neurons in dorsal root ganglion, info comes in though dorsal roots dorsal ramus efferent to back, afferent from back, somatic ventral ramus efferent to front, afferent from front, somatic epineurium surrounds the entire nerve nerve made of fasicles and blood vessels perineurium surrounds each fascicle fasicle made of endoneurium covered axons 3 protective layers to the brain dura mater, arachnoid mater, pia mater dura mater outermost layer, dense fibrous and tough, outer and inner layers, can separate to form venous sinuses, form dural folds dural folds separate major divisions of brain, made by inner layer of dura mater, falx cerebri, falx cerebelli, tentorium cerebelli, provide stability of brain falx cerebri separates cerebral hemispheres falx cerebelli separates the two hemispheres of the cerebellum tentorium cerebelli separates cerebrum from cerebellum, transverse venous sinuses located where 2 layers of duramater separate, collecting veins, collect venous blood from brain and old CSF after cycled through ventricular system arachnoid mater layer beneath dura mater and above pia mater, spider like apperance, does not extend into sulci, contains blood vessels, ft. sub arachnoid space and arachnoid granulations subarachnoid space layers/legs like pier at beach filled with cerebro spinal fluid and blood vessels, forms gel cushion arachnoid granulations perforate inner layer of dura mater forming granulations, transports old CSF from sub arachnoid space into venous sinus pia mater inner layer of the meninges, transparent and delicate, blood vessels and arachnoid space sit ontop of it, adheres to brain and follows gyri and extends into sulci ventricular system network of interconnected spaces within brain, filled with CSF which nourishes and protects brain, lined with ependymal cells which circulate the CSF produced by choriod plexus ventricles 2 lateral ventricles, third ventricle, cerebral aqueduct, 4th ventricle, central canal (spinal cord) lateral ventricles 2 of them, 1 in each hemisphere, in cerebrum 3rd ventricle located in the diencephalon cerebral aqueducts connects the third and fourth ventricles, located midbrain 4th ventricle located level with cerebellum, has small holes into the sub arachnoid space cerebro spinal fluid surrounds CNS, provides support and cushioning, transport nutrients and waste, produced by choroid plexus within ventrticles frontal lobe motor control and language/personality parietal lobe somatosensory occipital lobe vision temporal lobe memory and hearing central sulcus between frontal and parietal lobes parieto-occipital sulcus between parietal and occipital lobes lateral sulcus between temporal and parietal/frontal lobes transverse fissure separates cerebrum from cerebellum Diencephalon