A&P LAP 5 Study Guide PDF

Anatomy LAP 5 Study Guide Multiple Choice Questions: 1.​ How is the nerve stimulated? -​ An electrode delivers a small electrical impulse that triggers a signal to be sent along the nerve fiber to the brain or muscle causing a response like a sensation or muscle...

Anatomy LAP 5 Study Guide Multiple Choice Questions: 1.​ How is the nerve stimulated? -​ An electrode delivers a small electrical impulse that triggers a signal to be sent along the nerve fiber to the brain or muscle causing a response like a sensation or muscle contraction 2.​ What signals acetylcholine release? -​ An action potential reaches the axon terminus which causes the voltage-gated calcium channels to open → lets the calcium flow into the cell which triggers the release of acetylcholine 3.​ What is the main neurotransmitter in the nervous system? -​ glutamate 4.​ What is EPSP? -​ Excitatory Postsynaptic Potential → temporary depolarization of the neuron’s membrane potential 5.​ What is IPSP? -​ Inhibitory Postsynaptic Potential → electrical signal that makes a postsynaptic neuron less likely to fire an action potential (hyperpolarizing the membrane potential) 6.​ What is the difference between special and temporal summation? -​ SS: multiple neurons fire at the same time at different places on the postsynaptic neuron adding their signals together to reach the threshold for an action potential -​ TS: one neuron fires rapidly in succession causing the postsynaptic potential to build up over time to reach the threshold for an action potential 7.​ What are all the anatomical parts of a nerve and what happens at each part? -​ Axons: cord-like groups of fibers in the center of your nerve -​ Dendrites: branches that carry electrical impulses -​ Endoneurium: a layer of connective tissue that surrounds a group of axons (fascicles) 8.​ What is the difference between the central and peripheral nervous system? -​ CNS: consists of the brain and spinal cord -​ PNS: made up of all the nerves that branch out from the spinal cord and extend to the rest of the body 9.​ What are the different types of neurons? -​ Motor (control muscle movements) -​ Sensory (carries sensory info to the brain and spinal cord) -​ Interneurons (located between the sensory and motor neurons) -​ Unipolar: one axon that splits into dendrites -​ Bipolar: one axon and one dendrite extending from the body -​ Multipolar: one axon and multiple dendrites extending from the body 10.​ What is the difference between the somatic and autonomic nervous systems? -​ SNS: controls voluntary movements (walking, reaching, etc) -​ ANS: regulates the involuntary bodily functions (heart rate, digestion, breathing, etc) 11.​ What is the difference between the efferent and afferent divisions of the nervous system? -​ AD: carries sensory information from the body towards the CNS -​ ED: carries motor commands from the CNS to the muscles/glands 12.​ What are the different types of neuroglia and what are their functions? -​ Astrocytes: maintaining the extracellular environment (providing nutrients to neurons, regulating blood flow, and guiding neural developments) -​ Oligodendrocytes (CNS): produce myelin sheaths that insulate the axons of neurons, facilitating rapid signal transmission -​ Microglia (CNS): acts as the immune cells of the CNS (engulfs debris, pathogens, and damaged cells through phagocytosis) -​ Schwann cells (PNS): produce myelin sheaths around the axons of peripheral neurons -​ Satellite cells (PNS): surround the neuron cell bodies providing structural support and regulating the microenvironment around the neurons 13.​ What is the function of the sodium-potassium pump? -​ Actively transport sodium ions out of the cell and potassium ions into the cell 14.​ What are the different types of channels and gates in the nerve cell? -​ Voltage-gated channels (sodium and potassium) -​ Ligand-gated channels – also known as chemically gated channels (activated by chemical signals) -​ Mechanically-gated channels 15.​ What is the difference between repolarization, depolarization, and hyperpolarization? -​ RP: the return of the membrane potential to its resting state caused by efflux of potassium ions -​ DP: cell membrane becoming becoming less negative (more positive) due to influx of positive ions -​ HP: when the membrane potential becomes even more negative than the resting state due to continued potassium ion outflow 16.​ What is the difference between voltage-gated and chemically gated channels? -​ VG: opens and closes in response to changes in the membrane potential of a cell -​ CG: opens and closes when a specific chemical molecule binds to it 17.​ What is the structural classification for neurons and which one is most abundant in the CNS (central nervous system)? -​ Multipolar – most abundant -​ Bipolar -​ Unipolar 18.​ What happens when the sodium and potassium channels open and how does it affect the cell polarity? -​ The opening of the sodium channels leads to a positive shift in cell polarity, whereas the opening of potassium channels leads to a negative shift 19.​ What are the main steps in the generation of an action potential? -​ Depolarization (sodium influx)  -​ Reaching the threshold potential -​ Rapid sodium channel opening -​ Overshoot (positive peak due to influx of sodium ions) -​ Repolarization (potassium efflux) -​ Hyperpolarization (membrane potential slightly dips) 20.​ What is the none-or-all principle? -​ A response to a stimulus will either be a full, complete response or there will be no response at all (the strength of the stimulus doesn’t affect the intensity of the response if it reaches the threshold for activation 21.​ Identify what happens at the different parts of the nerve action potential graph. 22.​ What is the difference between continuous propagation and saltatory propagation? -​ CP: gradual movement of an action potential along an unmyelinated axon, where the electrical signal travels along the entire length of the axon -​ SP: describes the jumping of an action potential forms from one node of Ranvier to the next along a myelinated axon → much faster signal transmission 23.​ What is the threshold? -​ The minimum level of energy or membrane potential that must be reached to trigger a physiological or psychological response 24.​ What is the difference between absolute refractory and relative refractory? -​ AR: the cell is unresponsive -​ RR: the cells get gradually more responsive, but still require a strong stimulus to trigger a response Essay Question: ​ What are myelinated and unmyelinated neurons used for and how/when do they develop? -​ Myelinated: -​ Function: transmit nerve impulses quickly -​ Location: found in the central and peripheral nervous system (especially in those that require fast signal transmission) -​ How it works? -​ The myelin sheath insulates the axon, allowing electrical impulses to jump between nodes of Ranvier -​ UM: -​ Function: transmit nerve impulses more slowly than myelinated neurons -​ Location: the central and peripheral nervous system (especially in group C nerves that transmit pain or itching signals -​ How it works? -​ Action potentials travel continuously along the axon How do neurons stimulate and how do they conduct information? -​ They stimulate one another by sending electrical impulses (action potentials) along axons which trigger the release of chemical messengers (neurotransmitters) across the synapse to reach the dendrites of the receiving neuron.