Nervous System I

Neuron (nerve cell) = basic structural and functional unit of the nervous system Neuroglia = major supporting cells of neurons Nerve = bundle of axons (or nerve fibres) and their sheaths (outer covering) Sensory receptors = separate specialised cells which detect temperature, pain, touch, pressure, light, sound, odour and other stimuli

Action potential = electrical signal Effector organ or effector cell = the organ, tissue or cell in which an effect or an action takes place Synapse = junction of a neuron with another cell e.g., end of a neuron with a muscle cell or another neuron Autonomic = The involuntary division of the peripheral nervous system which innervates smooth muscle, cardiac muscle or glands

Axon = A nerve fiber extending from the cell body of a neuron Central Nervous System = A subdivision of the nervous system which consists of the brain and spinal cord Dendrites = Cellular projects that extend from the cell body of a neuron Enteric = Referring to the digestive tract

<p>Ion channels = A membrane protein channel through which an ion moves Motor = A division of the peripheral nervous system that transmits action potentials from the central nervous system to effector organs e.g. muscles or glands Myelination = The process by which a myelin sheath wraps around an axon Neuroglial cells = Supporting cells of the nervous system</p> Signup and view all the answers

<p>Neuron = The basic structural unit of the nervous system Neurotransmitters = A chemical that transmits information from the neuron to its effector cell Peripheral Nervous system = All nervous tissue outside the central nervous system which includes the sensory receptors, nerves, ganglia and plexuses Polarised = The existence of opposite charges across the cell membrane</p> Signup and view all the answers

<p>Receptors = Cell membrane proteins to which a ligand binds Resting membrane Potential = The electrical charge difference across the cell membrane in an unstimulated or resting cell Saltatory conduction = The conduction of an action potential from one node of Ranvier to another Sensory = A division of the peripheral nervous system that transmits action potentials from sensory receptors to the central nervous system</p> Signup and view all the answers

<p>Somatic = The voluntary division of the peripheral nervous system which innervates skeletal muscle Synapse = A junction between the presynaptic and postsynaptic cells Vesicles = Cytoplasmic organelles that contain neurotransmitters Voltage-gated Channel = Gated ion channels that open or close when there is a change in membrane potential</p> Signup and view all the answers

<p>Receive internal and external sensory input, integrate information, motor output, maintaining homeostasis, establishing and maintaining mental activity</p> Signup and view all the answers

<p>31</p> Signup and view all the answers

<p>Plexus</p> Signup and view all the answers

<p>central nervous system (CNS), the peripheral nervous system (PNS)</p> Signup and view all the answers

<p>CNS = brain CNS = spinal cord PNS = sensory receptors, cranial nerves, spinal nerves PNS = ganglia, plexuses</p> Signup and view all the answers

<p>Cranial nerves = 12 pairs Spinal nerves = 31 pairs Ganglia = collection of neuron cell bodies outside the CNS Plexuses = extensive network of usually axons outside CNS</p> Signup and view all the answers

<p>peripheral, central, 3, somatic, automatic, enteric, sensory, motor, sensory, motor, sensory, motor.</p> Signup and view all the answers

<p>Somatic N.S = voluntary and under conscious control Autonomic N,S = Involuntary and under subconscious control Somatic N.S = Action potentials in the motor neurons travel from the CNS to the skeletal muscles Autonomic N.S = Action potentials in the motor neurons travel from the CNS to smooth or cardiac muscle, or glands</p> Signup and view all the answers

<p>Somatic N.S = single neuron system, one synapse Autonomic N.S = Two-neuron system, two synapses Somatic N.S = Cell bodies are located in the CNS Autonomic N.S = Cells bodies of first neuron are located in the CNS and second in an autonomic ganglion</p> Signup and view all the answers

<p>Somatic N.S = skeletal muscles contracts Autonomic nervous system = target tissues stimulated or inhibited Somatic N.S = myelinated axons Autonomic N.S = preganglionic are myelinated and postganglionic are unmyelinated</p> Signup and view all the answers

<p>Nerve plexuses</p> Signup and view all the answers

<p>Stimulating and inhibiting smooth muscle contraction</p> Signup and view all the answers

<p>Sensory = collects input from specialised receptors and transmit the input as electrical signals to the CNS Motor = transmit electric signals from the CNS Sensory = cell body located in the dorsal root ganglion (outside the CNS) Motor = cell body located inside the CNS</p> Signup and view all the answers

<p>False</p> Signup and view all the answers

<p>Sympathetic = Thoraco-lumbar region Parasympathetic = Cranial-sacral regions Sympathetic = increased heart rate, increased respiratory rate, sweating, pupil dilation Parasympathetic = stimulates digestion, defaecation, diuresis, pupil constriction</p> Signup and view all the answers

<p>Star-shaped, highly branched cells that scaffold CNS cells and capillaries = astrocytes Cells that have a role in the insulation of axons in CNS = oligodendrocytes Cells that phagocytose foreign substances, necrotic tissue and pathogens = microglial cells Cells that line the ventricles of brain and central canal of spinal cord have a role in the production and regulation of cerebrospinal fluid = ependymal cells</p> Signup and view all the answers

<p>Cells that surround neuron cell bodies in sensory and autonomic ganglia, and provide support and nutrition to cell bodies = satellite cells Cells that have a role in the insulation of axons in PNS = Schwann cells filler 1 = filler 1 filler 2 = filler 2</p> Signup and view all the answers

<p>motor neuron = ventral horn Sensory neuron = dorsal root ganglion somatic (motor division) = ventral root -&gt;effector autonomic (motor division) = ventral root -&gt;autonomic ganglion -&gt;effector</p> Signup and view all the answers

<p>Sensory neurons = unipolar neurons with on cell body and one process Bipolar neurons = unipolar neurons with one cell body and two processes, specialised sensory neurons in locations like the retina of the eye, and nasal cavity Motor neurons, interneurons = multipolar neurons with one cell body and many dendritic processes Neuron structural classifications = multipolar, bipolar, unipolar</p> Signup and view all the answers

<p>Conducts action potential from sensory receptors to CNS, afferent neuron = sensory neuron Conducts action potential away from CNS toward muscles or glands, efferent neuron = motor neuron Conducts action potential within CNS from one neuron to another = interneuron spare = spare</p> Signup and view all the answers

<p>100 billion neurons</p> Signup and view all the answers

<p>Structure and/or function of the neuron</p> Signup and view all the answers

<p>Neuron</p> Signup and view all the answers

<p>To receive, integrate and respond to information</p> Signup and view all the answers

<p>10-50:1</p> Signup and view all the answers

<p>Supporting neurons</p> Signup and view all the answers

<p>6 different types of neuroglia: 4 in CNS, 2 in PNS</p> Signup and view all the answers