Show Recommended textbook solutions
 Hole's Human Anatomy and Physiology13th EditionDavid N. Shier, Jackie L. Butler, Ricki Lewis 1,402 solutions
Hole's Human Anatomy and Physiology15th EditionDavid Shier, Jackie Butler, Ricki Lewis 1,950 solutions
Anatomy and Physiology Coloring Workbook11th EditionElaine N. Marieb 927 solutions
Essentials of Human Anatomy and Physiology11th EditionElaine N. Marieb 613 solutions
Home Subjects Expert solutions Create Log in Sign up Upgrade to remove ads Only ₩37,125/year
Terms in this set (28)What is a reflex? It is a rapid motor response to a stimulus. What are the five parts of a reflex arc? 1) Receptor Explain the Receptor Receptor responds to a stimulus which is any change in the external/internal environment. The sensory structures initiate impulse via local depolarization (graded potential) Explain the Sensory Neuron Receptor to axon termination in CNS. Transmits afferent impulse Explain the Integration Center Sensory impulse to motor impulse. Direct Monosynaptic or polysynaptic region in CNS. Motor Neuron Efferent impulses from integration center to effector. Explain Effector
Muscle Fiber or gland. Responds to efferent impulse-increase/decrease muscle contraction or gland secretion. What are the four types of somatic spinal reflexes? 1) stretch reflex Define Agonist A muscle that produces a particular movement (ex: flexion) Define Antagonist A muscle that reverses the movement (ex: extension) Describe Stretch Reflex Monosynaptic reflex = 1 synapse in CNS (1 sensory neuron + 1 motor neuron) to control agonist. Describe the phases of muscle contraction from unstretched to coactivation. unstretched muscle- action potentials are generated at a constant rate in the associated 1a fiber stretched muscle- stretching activates the muscle spindle, increasing the rate of APs. Only motor neurons activated- only the extrafusal muscle fibers contract. the muscle spindle becomes slack and no APs are fired. It is unable to signal further length changes. Coactivation- Both extrafusal and intrafusal muscle fibers contract. Muscle spindle tension is maintained and it can signal changes in length. Coactivation and gamma motor output Without coactivation, CNS could not get information about muscle changes in the muscle length during contraction Gamma motor output can be increased or decreased by the brain and allows modification of the stretch reflex (makes the muscle spindle more/less reactive) In a muscle spindle, what are the two types of afferent endings Primary sensory - Type Ia Fibers which is stimulated by rate + amount of stretch Secondary Sensory - Type II fibers stimulated by amount of stretch What parts are the distal ends of the muscle spindle? Contractile
(actin + myosin) What are the steps to contraction of agonist? Sensory neuron impulses via dorsal root synapse with motor neuron (efferent) - anterior gray horn (alpha) motor neuron exits spinal cord via ventral root Action potentials are then generated at agonist muscle leading to contraction Result= limit stretch Define Reciprocal Inhibition Sensory neuron synapses with inhibitory interneurons in the CNS to inhibit motor neurons to the antagonist muscle (polysynaptic) Relaxation of agonist The events of the stretch reflex 1) when muscle spindles are activated by stretch, the associated sensory neurons transmit afferent impulses at higher frequency to the spinal cord. 2) The sensory neurons synapse directly with alpha motor neurons which excite extrafusal fibers of the stretched muscle. Afferent Fibers also synapse with interneurons that inhibit motor neurons controlling antagonistic muscles 3) Efferent impulses of alpha motor neurons cause the stretched muscle to contract which reverses the stretch. The efferent impulses of the alpha motor neurons to the antagonist muscles are reduced (reciprocal inhibition) What is the purpose of the motor neurons? The motor neurons send activating impulses to the antagonist causing it to contract What is the purpose of the interneurons? Make inhibitory synapses with ventral horn neurons that prevent the antagonist muscles from resisting the contraction of the agonist. Explain Tendon Reflex -ipsilateral, polysynaptic What are the sequence of events in a tendon reflex? - when increased tension is applied to the tendon, nerve impulses are generated in the sensory neuron. Synapses with inhibitory interneuron in CNS. Motor neuron to agonist is inhibited. Result: relaxation of agonist muscle. Define Reciprocal Activation Sensory neuron synapses with excitatory interneurons in the CNS stimulate motor neurons to the antagonist muscle Define Ipsilateral Reflex Sensory info enters and motor output leaves spinal cord on same side Define Contralateral Reflex Sensory info enters on one side and motor output leaves spinal cord on opposite side. Explain Flexor (withdrawal) reflex -Ipsilateral, polysynaptic Explain crossed extensor Reflex -ipsilateral withdrawal reflex Define the intersegmental reflex arc Ascending and descending branches of sensory neurons involve different levels of the spinal cord resulting in several muscle groups involved at same time. One single sensory neuron can activate several motor neurons and many effector responses. Sets with similar termsReflexes20 terms millereric17 Chapter 13: Spinal control of movement62 terms melikimmy 13. Spinal Cord Reflexes97 terms morgmurph Chapter 13 (Exam 2)72 terms lmonsalv Sets found in the same folderHuman Physiology Exam 155 terms Zoellnerb Physiology ch 11 test your knowledge34 terms Kay_F1 Digestive System Physiology87 terms ecbaker12 Hypothalamus- pituitary-thyroid axis53 terms hailey_button Other sets by this creator
Blood Vessels23 terms jpagsibi Heart35 terms jpagsibi blood34 terms jpagsibi BIo124 Final Exam notes70 terms jpagsibi Recommended textbook solutions
Clinical Reasoning Cases in Nursing7th EditionJulie S Snyder, Mariann M Harding 2,512 solutions
Foundations for Population Health in Community and Public Health Nursing5th EditionJeanette Lancaster, Marcia Stanhope 156 solutions
Health: The Basics12th EditionRebecca J. Donatelle 319 solutions Health16th EditionRebecca J. Donatelle 391 solutions Other Quizlet setsNeuroanatomy week 9-1011 terms joseph_camargo1 Anatomy Semester 2 Exam129 terms TiaraHale81 OT 313 Final Essays21 terms lenishaaxo Autonomic Nervous System43 terms ImeEtokebe Related questionsQUESTION What are the three structures found in all mammalian cells? 11 answers QUESTION What are the pulmonary stretch receptors? 15 answers QUESTION How do cells communicate in the body? 15 answers QUESTION What are the 2 types of autonomic nervous system? 15 answers Which classification of neurons initiate muscle contraction and activate glands?Motor neurons are responsible for integrating signals from the brain to the muscles, glands, and organs that intend to carry out the required motor function.
What type of neuron contacts a muscle fiber and initiates a muscle contraction quizlet?Upper motor neurons directly contact and stimulate skeletal muscle fibers to contract.
Which substance is released by motor neurons to initiate a muscle contraction?Acetylcholine (ACh) is a neurotransmitter released by motor neurons that binds to receptors in the motor end plate. Neurotransmitter release occurs when an action potential travels down the motor neuron's axon, resulting in altered permeability of the synaptic terminal membrane and an influx of calcium.
What stimulates muscles to contract quizlet?When a nerve impulse arrives at a muscle fiber, calcium ions trigger muscle contraction, and ATP provides the energy. The head of a myosin molecule can attach to the actin of a thin filament. When an ATP molecule binds to the myosin head, it detaches from the actin filament.
|
Which classification of neurons initiate muscle contraction and activate glands Quizlet
zusammenhängende Posts
Urheberrechte © © 2024 defrojeostern Inc.
