Autonomic Nervous System Overview
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Questions and Answers

What is the primary function of glucagon in the body?

  • To increase blood glucose levels (correct)
  • To decrease blood glucose levels
  • To promote fat storage
  • To stimulate cell division

    • Which condition results from the hypersecretion of growth hormone after the epiphyseal plates have closed?

  • Acromegaly (correct)
  • Insulin resistance
  • Dwarfism
  • Gigantism

    • What characterizes Type 1 Diabetes?

  • Hyperactivity of glucagon
  • Overproduction of insulin
  • Autoimmune destruction of beta cells (correct)
  • Insulin receptor desensitization

    • Which gland is NOT regulated by the pituitary gland?

    <p>Parathyroid glands</p> Signup and view all the answers

    Which of the following hormones is primarily responsible for decreasing blood glucose levels?

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

    What is the primary function of the autonomic nervous system?

    <p>Adjust the activity of glands and involuntary muscles</p> Signup and view all the answers

    Which division of the autonomic nervous system is primarily responsible for 'fight or flight' responses?

    <p>Sympathetic nervous system</p> Signup and view all the answers

    Which neurotransmitter is primarily associated with the parasympathetic nervous system?

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

    What is the role of visceral reflexes in the autonomic nervous system?

    <p>Maintain homeostasis without conscious involvement</p> Signup and view all the answers

    Which of the following best describes the sympathetic nervous system's effect on blood flow during a stress response?

    <p>Redirected blood flow to skeletal muscles</p> Signup and view all the answers

    In which anatomical area do sympathetic nerves predominantly originate?

    <p>Thoracolumbar region</p> Signup and view all the answers

    What characteristic distinguishes the parasympathetic nervous system from the sympathetic nervous system?

    <p>More selective actions</p> Signup and view all the answers

    Which nerve is responsible for carrying a significant portion of parasympathetic fibers?

    <p>Vagus nerve</p> Signup and view all the answers

    Which part of the brain is primarily involved in the perception of pain modulation?

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

    What type of cells in the taste buds are responsible for releasing neurotransmitters?

    <p>Taste receptor cells</p> Signup and view all the answers

    Which of the following statements about olfactory cells is correct?

    <p>They are replaced every 60 days.</p> Signup and view all the answers

    What is the primary function of the ossicles in the middle ear?

    <p>Sound amplification</p> Signup and view all the answers

    Which structure in the nose detects odors?

    <p>Olfactory mucosa</p> Signup and view all the answers

    What primarily determines the pitch of a sound?

    <p>The frequency of the wave</p> Signup and view all the answers

    How does the auditory tube in children differ from that in adults?

    <p>It is more horizontal and shorter.</p> Signup and view all the answers

    Which structure is responsible for the perception of static equilibrium?

    <p>Utricle and saccule</p> Signup and view all the answers

    Which taste is specifically associated with alkaloids?

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

    How does loudness get determined in the auditory system?

    <p>By the number of hair cells that bend</p> Signup and view all the answers

    What is the primary role of the basilar membrane in the cochlea?

    <p>To convert vibrations into nerve impulses</p> Signup and view all the answers

    Which part of the ear does the tympanic membrane transmit vibrations to?

    <p>Middle ear</p> Signup and view all the answers

    What role do otoliths play in the vestibular system?

    <p>They provide weight to the membrane for head position changes</p> Signup and view all the answers

    Which type of equilibrium is associated with angular changes in rate of rotation?

    <p>Dynamic equilibrium</p> Signup and view all the answers

    Which feature of the auditory system detects frequency ranges of high pitches?

    <p>Basilarmembrane vibrating in the higher frequencies</p> Signup and view all the answers

    What is the function of the oculomotor nerve in relation to eye movement?

    <p>Innervates the majority of extraocular muscles</p> Signup and view all the answers

    What structure in the eye is responsible for controlling the diameter of the pupil?

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

    Which layer of the eye is highly vascular and contains pigment?

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

    What is the primary function of the vitreous body in the eye?

    <p>Maintains the shape of the eye</p> Signup and view all the answers

    What condition is characterized by a clouding of the lens?

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

    Which type of vision defect is caused by an eyeball that is too short?

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

    Where is the highest concentration of cones located within the eye?

    <p>Fovea centralis</p> Signup and view all the answers

    What part of the eye has no photoreceptors and is known as the blind spot?

    <p>Optic nerve</p> Signup and view all the answers

    What process involves the bending of light rays to focus an image on the retina?

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

    What type of hormones are primarily made from cholesterol?

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

    Which part of the brain processes visual information from the left visual field?

    <p>Right occipital lobe</p> Signup and view all the answers

    How do endocrine glands primarily release their secretions?

    <p>Directly into the bloodstream</p> Signup and view all the answers

    Which type of hormone receptor determines which tissues respond to a hormone?

    <p>Hormone receptor</p> Signup and view all the answers

    What is the main difference between endocrine and exocrine glands?

    <p>Endocrine glands secrete into the bloodstream, while exocrine glands secrete onto surfaces.</p> Signup and view all the answers

    What class of hormones is made from amino acids and hydrophilic in nature?

    <p>Peptide hormones</p> Signup and view all the answers

    What hormone behavior is marked by a slow response time following a stimulus?

    <p>Endocrine response</p> Signup and view all the answers

    Which of the following is a function of hormone receptors?

    <p>To determine tissue response</p> Signup and view all the answers

    Study Notes

    Autonomic Nervous System (ANS)

    • Self-governed
    • Part of the efferent division
    • Adjusts gland and smooth/cardiac muscle activity.
    • Involuntary and unconscious
    • Two divisions: sympathetic and parasympathetic
    • Visceral reflexes
      • Involuntary, stereotyped, slower than somatic reflexes.
      • Maintain homeostasis (example: Baroreflex regulates blood pressure)

    Somatic vs. Autonomic Motor Control

    • Somatic:

      • Voluntary skeletal muscle control
      • One neuron from spinal cord to muscle
      • Only myelinated fibers
      • Acetylcholine (ACh) always excitatory

    • Autonomic:

      • Involuntary control of cardiac, smooth muscles, and glands
      • Two neurons from spinal cord
      • Myelinated preganglionic and unmyelinated postganglionic fibers

    Sympathetic Nervous System (SNS)

    • "Fight or Flight" response
    • Activated by stress, trauma, danger, or exercise
    • Increases blood flow to skeletal muscles, heart rate, blood pressure, respiration rate, blood glucose
    • Dilates pupils, increases alertness, and reduces blood flow to digestive system.
    • Thoracolumbar division (T1-L2)
    • Short preganglionic fibers, long postganglionic fibers (sympathetic chain ganglia)
    • Some nerves have widespread effect

    Parasympathetic Nervous System (PSNS)

    • "Rest and Digest"
    • Maintains normal body maintenance and calming effects.
    • Causes: reduced heart rate, constricted pupils, increased digestion, waste elimination, reproduction, glycogen synthesis
    • Craniosacral division (brainstem, S2-S4 spinal nerves)
    • Long preganglionic fibers, short postganglionic fibers (terminal ganglia)
    • Localized effect

    Neurotransmitters of the ANS

    • Somatic: CNS to skeletal muscles, always excitatory, uses acetylcholine (Ach) + nicotinic receptors
    • Parasympathetic: CNS ganglion → smooth/cardiac muscle/glands, Ach + nicotinic receptors (excitatory), muscarinic receptors (inhibitory)
    • Sympathetic: CNS ganglion → smooth/cardiac muscle/glands, norepinephrine (NE) + adrenergic receptors (typically excitatory; some inhibitory)
    • Adrenal medulla secretes Epinephrine (Epi) and norepinephrine (Ne) directly into the bloodstream

    Dual Innervation

    • Most organs receive both SNS and PSNS input.
    • Effects can be antagonistic (opposing, e.g., pupil dilation vs. constriction) or cooperative (unifying, e.g., salivation).

    Senses (Afferent division)

    • Sensory receptors convert stimuli into nerve signals.
    • Sensation is awareness of a nerve signal reaching the brain.
    • Sensory receptors detect stimulus, convert it to an Action Potential (AP), and send it through sensory neurons
    • Sensory coding determines location, intensity, duration, and type of stimulus.
    • Receptive field = the area innervated by a sensory neuron.
    • Stimulus intensity = increased stimulus strength = increased neuron activation = higher frequency of APs
    • Sensory adaptation = firing rate of sensory neurons decreases or stops over time
      • Phasic receptors adapt rapidly (e.g., smell, hair movement).
      • Tonic receptors adapt slowly (e.g., body position, pain).
    • Stimulus type (modality) = different receptors designed for specific stimuli.
    • Labelled line code (specific pathways for specific sensory input)

    Pain

    • Discomfort caused by injury or noxious stimulation leading to protective actions
    • Fast pain = myelinated fibers (sharp)
    • Slow pain = unmyelinated fibers (aching)
    • Referred pain = visceral pain perceived as originating from another area

    Sensory Pathways

    • Ascending pathways transmit general sensory information.
    • They usually have three neurons (first, second, third-order neurons), and relay station in thalamus (somesthetic cortex)
    • Pain signals are sent to the limbic system and hypothalamus, proprioception to cerebellum, visceral to medulla oblongata

    Taste (Gustation)

    • Chemicals stimulate taste cells.
    • Five basic tastes: salty, sweet, sour, bitter, umami
    • Taste perception involves combination of tastes + smell, temperature, and texture
    • Taste cells are epithelial cells with chemoreceptors
    • Taste cells replaced every 7-10 days

    Smell (Olfaction)

    • Olfactory receptors in olfactory mucosa detect odors.
    • Olfactory cells have chemoreceptors for specific odorants.
    • Olfactory information does not go through the thalamus

    Anatomy of the Ear

    • Outer ear: funnels sound to eardrum. Middle ear: ossicles transmit vibrations, eardrum to inner ear. Inner ear: balance (vestibule/semicircular ducts), hearing (cochlea)
    • Sound waves cause vibrations in the cochlea.
    • Hair cells convert vibrations into nerve impulses.
    • Pitch is determined by which part of the basilar membrane vibrates.

    Equilibrium (Vestibular Apparatus)

    • Static equilibrium: head position (utricle and saccule).
    • Dynamic equilibrium: head movement (semicircular canals).
    • Otoliths increase the weight and inertia of the membranes.
    • Information travels to the vestibular cortex and other areas for balance control.

    Vision

    • Six extrinsic eye muscles help move the eye
    • Components (3 layers): fibrous layer (sclera, cornea), vascular layer (choroid, iris, ciliary body), neural layer (retina, optic nerve)
    • Retina contains photoreceptors (rods and cones).
    • Image formation - involves reflection and refraction of light rays, accommodation adjusts the lens's shape
    • Defects: myopia (nearsightedness), hyperopia (farsightedness).
    • Visual pathways: left visual field to right brain, and vice versa

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    Autonomic Nervous System Notes PDF

    Description

    Explore the intricacies of the Autonomic Nervous System (ANS), its functions, and how it contrasts with somatic motor control. This quiz will test your understanding of the sympathetic and parasympathetic divisions and their roles in regulating bodily functions and maintaining homeostasis.

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