Autonomic Nervous System & Hearing: Overview of Reflexes, Neurotransmitters, & Ear Anatomy, Study notes of Physiology

Download Autonomic Nervous System & Hearing: Overview of Reflexes, Neurotransmitters, & Ear Anatomy and more Study notes Physiology in PDF only on Docsity! Chapter 15 I. Overview of ANS a. Self-governing (happen automatically) b. Visceral motor division aka ANS i. Sympathetic division 1. Prepares body for physical activity ii. Parasympathetic division 1. Calms many body functions c. Responsible for body’s visceral reflexes i. Visceral reflex arc 1. Receptors 2. Afferent neurons 3. Interneruons 4. Efferent neurons 5. Effectors d. Most organs innervated by parasympathetic and sympathetic fibers. Sometimes they have cooperative (same) effect but sometimes they have antagonist (opposite) effect. II. Autonomic effects on target organs a. Neurotransmitters and their receptors i. How can different autonomic neurons have different effects constricting some vessels but dilating others? ii. Effects determined by: 1. Types of neurotransmitters release and 2. Types of receptors found on target cells iii. Cholinergic fibers 1. All preganglionic neurons release ACh (in para & sym) iv. Cholinergic receptor: receptor of ACh 1. All parasympathetic postganglionic neurons release ACh sympathetic postganglionic release ACh or norepinephrine. 2. Two types: a. Nicotinic receptors: stimulated by nicotine. Almost always excitatory. b. Muscarinic receptors v. Norepinephrine is secreted by many sympathetic postganglionic neurons 1. Adrenergic fibers 2. Adrenergic receptors a. Alpha-adrenergic receptors: usually excitatory b. Beta-adrenergic receptors: usually inhibitory Pages 562-575 Visceral Reflexes-Neurotransmitters Chapter 16 I. Hearing a. Properties and types of sensory receptors i. Sensory receptor ii. Transduction: energy the brain can use iii. Receptor potential 1. Strong receptor potential > action potential iv. Sensation v. Must turn sound waves into something that the brain can read (nerve stimuli) b. General properties of receptors i. Sensory receptors transmit 4 kinds of information 1. Modality 2. Location 3. Intensity 4. Duration c. Hearing i. Outer ear 1. Auricle: cartilage 2. Auditory canal: passageway from outer ear to tympanic membrane 3. External acoustic meatus: opening of auditory canal ii. Inner ear 1. Housed in bony labyrinth 2. Membranous labyrinth a. Filled with endolymph b. Floating in perilymph 3. Vestibule a. Saccule b. Utricle 4. Cochlea: organ of hearing. Transduction of sound waves a. Damage to hairs can cause hearing loss b. Snail like c. Scala vestibule d. Scala media (cochlear duct) has hairs that are in contact with basilar membrane. When basilar membrane is stimulated it move stimulating the hairs which end in