Anatomy Neuroanatomy & Physiology. Michelle Heard, Katie McGrath & Shannon Woo

Transcription

1 Anatomy Neuroanatomy & Physiology Michelle Heard, Katie McGrath & Shannon Woo

2 Table of Contents Respiration: Structures & Processes Phonation: Structures & Processes Resonation and Articulation: Structures & Processes Neurons & Neural Transmission Peripheral & Autonomic Nervous Systems Central Nervous System a. b. c. d. e. Brainstem, RAS, Diencephalon, Basal Ganglia & Cerebellum Review Activity Cerebrum Review Activity Pyramidal & Extrapyramidal Activity Fibers, Ventricles & Layers Activity CSF & Blood Supply Activity

3 Respiration Structure & Processes Review Activity

4 Respiration- Anatomy Structures Lungs Bronchi Made of cartilage Extends from lungs to trachea. Trachea The right one is bigger 20 cartilaginous rings Extends from the larynx to the right and left bronchi Rib cage 12 pairs

5 Spinal Column consists of individual vertebrae: 7 cervical vertebrae (C1 - C 7) 12 thoracic vertebrae (T 1 - T 12) 5 lumbar vertebrae (L 1- L 5) 5 sacral vertebrae (S 1- S 5, fused in adults) 3-4 coccygeal vertebrae (fused and called the coccyx). Sternum or breastbone consists of three parts: Manubrium-uppermost part of sternum, provides attachment for the clavicle and the first rib. Corpus (Body)- long and narrow, cartilages of ribs 2-7 attach here. Xiphoid Process- small cartilaginous structure found at bottom of the body

6 The process of respiration...who can describe what happens?

7 Muscles of Inhalation

8 Muscles of Exhalation

9 Video Link of the muscles involved in respiration... Muscles of the thorax

10 Phonation Structure & Processes

11 Phonation Larynx Adduct: moves toward midline ABduct: moves away from midline Biological function Closure so that food and other substances does not enter the lungs Production of the cough reflex Closure to build subglottic pressure necessary for physical tasks

12 Phonation- Structures of the larynx Hyoid bone U shaped Muscles of the tongue and various muscles of the mandible, skull, and larynx attaches to the hyoid Epiglottis During the swallow the epiglottis retroflexes to cover the larynx What is the epiglottis made of?

13 Phonation- Structures of the larynx Thyroid cartilage Cricoid cartilage Forms the lateral and anterior walls of the larynx Protects the larynx Linked with the thyroid and paired with the arytenoids Completely surrounds the trachea Arytenoid cartilages Pyramid shaped cartilages Connected to the cricoid through the cricoarytenoid joint which allows sliding and circular movements

14 Phonation- Structures of the larynx Corniculate cartilages Sit on apex of arytenoid Assist in reducing the laryngeal opening when a person is swallowing Cuneiform cartilages Located under the mucous membrane that covers the aryepiglottic folds Stiffens and tenses the aryepiglottic folds

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16 Phonation- Structures of the larynx Vocal folds 3 Layers (or 5) Aryepiglottic folds Epithelium, lamina propria (deep, medial and superficial) and the vocalis muscle Composed of rings of connective tissue and muscle Extend from the tips of the arytenoid to the larynx Separate the laryngeal vestibule from the pharynx Helps preserve the airway Ventricular (false) vocal folds Vibrate only at a low fundamental frequency and usually not during typical phonation Compress during activities such as coughing and lifting

17 Phonation- Intrinsic Laryngeal Muscles Muscles (CN) Function Thyroarytenoid (X) Vibrates and produces sound Lateral cricoarytenoid (X) Adducts vocal folds Transverse arytenoid (X) Adducts vocal folds Oblique arytenoid (X) Pulls arytenoids medially Cricothyroid (X) Lengthens and thickens vocal folds Posterior Cricoarytenoid (X) ABducts vocal folds

18 Phonation- Extrinsic Laryngeal Muscles Elevators (CN) Depressors (CN) Digastric (V, VII) Thyrohyoid (XII) Geniohyoid (XII) Omohyoid Mylohyoid (V) Sternothyroid Stylohyoid (VII) Sternohyoid Hyoglossus (XII) Genioglossus (XII)

19 Physiology of Phonation Myoelastic-Aerodynamic Theory Vocal fold vibrate because of the forces and air pressure of air and the elasticity of the vocal folds Subglottic air pressure blows the vocal folds apart which sets the folds into vibration The pressure between the edges of the vocal folds decrease and the folds are sucked together Bernoulli Effect Caused by the increased speed of air passing between the folds Results in the folds sucking back together; this cycle occurs 100x second Mucosal Wave Action The epithelium and lamina propria (all three layers) slide and produce the mucosal wave Without the mucosal wave there is no ability to phonate Surgery can stiffen the vocal folds and limit the mucosal wave

20 Phonation- Neuroanatomy of the Vocal Mechanism Cortical Areas Area 4 (primary motor cortex) Area 44 (Broca s area) Areas 1, 2, 3 (somatosensory cortex Area 6 (supplemental motor cortex) Cerebellum Regulates motor movement Crucial for phonation and all other speech systems Cranial Nerves CN VII: innervates the posterior belly of the digastric muscle CN X SLN Internal branch: sensory information the larynx External branch: motor innervation to the cricothyroid RLN All motor innervation all of the other intrinsic muscles Supplies all sensory information below the vocal folds

21 Resonation & Articulation Structures & Processes

22 Resonance & Articulation Fundamentals of Resonation The modification of laryngeal tone by selective dampening or enhancing specific frequencies Laryngeal tone is modified by the pharynx, nasal cavity and oral cavity Nasal cavity: /m/, /n/ & /ŋ/ Oral cavity: all of the other sounds Source Filter Theory Energy from the vibrating vocal folds (source) is modified by the resonance characteristics of the vocal tract (filter)

23 Resonance & Articulation Fundamentals of Articulation The movement of joined anatomic parts, as well as the production of speech sounds that result from such movements What are the structured needed for resonance and articulation?

24 Resonation & Articulation Structures Pharynx Soft Palate Hard Palate Mandible Teeth Tongue Face: Lips & Cheek

25 Articulation- Pharynx Made up of of three structures: Laryngopharynx Oropharynx Begins superior to the larynx and ends at the base of the tongue Extends from the base of the tongue to the soft palate Nasopharynx Ends where the two nasal cavities begin Innervated by CN X and XI via the pharyngeal plexus Pharyngeal plexus- formed by the joining of CN X and XI

26 Articulation- Pharyngeal Muscles Muscle (CN) Function Salpingopharyngeus (X, XI) Elevates lateral pharyngeal wall Stylopharyngeus (IX) Elevates and opens pharynx Superior pharyngeal constrictor (X, XI) Constricts pharyngeal diameter Middle pharyngeal constrictor (X, XI) Narrows diameter of pharynx Cricopharyngeus (X, XI) Constricts superior orifice of esophagus Thyropharyngeus (X, XI) Reduces diameter of lower pharynx

27 Articulation- Soft Palate (aka the velum) Definition: a flexible muscular structure at the juncture of the oropharynx and the nasopharynx Uvula: a small cone shaped located at the tip of the velum The velum can be elevated or lowered Velopharyngeal closure: The soft palate is raised and the muscles of the pharynx move inward creating closure. Lack of adequate velopharyngeal closure results in a nasal sounding voice

28 Articulation- Muscles of the Soft Palate Muscle (CN) Function Levator veli palatini (X, XI) Elevates velum Tensor veli palatini (V) Tenses velum, elevates eustachian tube Palatoglossus (X, XI) Elevates and depresses velum Palatopharyngeus (X, XI) Narrows pharyngeal cavity, lowers velum

29 Articulation- Hard Palate Roof of mouth/floor of nasal cavity Premaxilla: most anterior portion of the palate, houses the four upper incisors Palatine Process: largest part of the palate, two portion fuse to midline during time in utero Failure to fuse causes a cleft palate Alveolar Process: houses the teeth

30 Articulation- Mandible Also known as the lower jaw Houses the lower teeth and forms the floor of the mouth Serves as the framework for the tongue and lower lip Function Open and closes the mouth Chewing food Hinged to the skull with muscles and tendons via the temporomandibular joint

31 Articulation- Muscles of the Mandible Elevators Muscle (CN) Function Masseter (V) Elevates mandible Temporalis (V) Elevates mandible Medial pterygoid (V) Elevates mandible Lateral pterygoid (V) Protrudes mandible

32 Articulation- Muscles of the Mandible Depressors Muscle Function Anterior belly of digastric (V) Depresses mandible, pulls hyoid forward Posterior belly of digastric (VII) Depresses mandible, pulls hyoid back Geniohyoid (XII) Depresses mandible Mylohyoid (V) Depresses mandible

33 Articulation- Teeth Major function of the teeth Baby teeth Appear usually around 6 to 9 months Babies usually have 20 teeth (10 per arch) Adult teeth 32 (16 per arch) Of the 16, 4 are incisors, 2 are canine, 4 are premolar, and 6 are molar) Occlusion Deciduous teeth Mastication Articulation: Labiodentals Refer to the way the two arches come together when the person bites down Normal if symmetrical and aligned Malocclusion Deviation in the position of individual teeth and the shape and relationship of the upper and lower dental arches Three different types of malocclusion

34 Articulation- Tongue Job of the tongue Sound production Linguadentals Lingua-alveolars Lingua palatal (fricative & affricates) Divided into 4 parts Eating Articulation Tip: thinnest and most flexible part of the tongue Blade: in resting position, it is the portion that lies inferior to the alveolar ridge Dorsum: largest part of tongue that lies in contact with the hard and soft palate Root: back and bottom portion of the tongue Lingual Frenulum: Connects the mandible with the tongue

35 Articulation- Muscles of the Tongue Intrinsic Muscle (CN) Function Superior longitudinal muscle (XII) Shortens tongue Inferior longitudinal muscle (XII) Shortens tongue Transverse muscles (XII) Narrows and elongates tongue Ventricular muscle (XII) Flattens tongue

36 Articulation- Muscles of the Tongue Extrinsic Muscle (CN) Function Genioglossus (XII) Forms bulk of tongue, retracts tongue Styloglossus (XII) Draws tongue up and back Hyoglossus (XII) Retracts and depresses tongue Chondroglossus (XII) Depresses tongue Palatoglossus Elevates tongue

37 Articulation- Muscles of the Lips & Cheeks Sound production: /m/, /p/, and /b/ Muscle Function Mentalis (VII) Pulls lower lip out Platysma (VII) Depresses mandible Risorius (VII) Retracts lips at corners Buccinator (VII) Constricts oropharynx Depressor labii inferioris (VII) Pulls lip down and out to dilate orifice Depressor anguli oris (VII) Presses upper and lower lip together, depresses corners of mouth

38 Articulation- Muscles of the Lips & Cheeks Muscle Function Zygomatic minor (VII) Elevates upper lip Zygomatic major (VII) Retracts and elevates angles of mouth Orbicularis oris (VII) Pulls lip together, serves as a point of insertion for other muscles Levator anguli oris (VII) Draws corner of mouth upward and toward medial Levator labii superioris (VII) Elevates upper lip Levator labii superioris alaeque nasi (VII) Elevates upper lip

39 Neurons & Neural Transmission Review Activity

40 Neurons & Neural Transmission Afferent neurons carry sensory/motor impulses away/toward the brain. Efferent neurons carry sensory/motor impulses away/toward the brain. Afferent= Sensory Efferent= Motor (think takes effort to move) The neuron cell has two main parts: Nerve fibers Soma (cell body)

41 QUARTERBACK Dendrites: RECEIVE impulses Axons: SEND OUT impulses RECEIVER Neurons communicate via SYNAPSES

42 Peripheral & Autonomic Nervous System Review Activity

43 Peripheral Nervous System The peripheral nervous system (PNS) is a collection of nerves that are outside the skull and spinal column. These nerves carry motor/sensory impulses which originate in the peripheral sense organs, to the brain, and motor/sensory impulses which originate in the brain, to the glands and muscles of the body. The PNS contains three types of nerves: Cranial- 12 pairs Spinal- 31 pairs Autonomic

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45 Damage to CN s result in... Trigeminal (V) - mixed nerve possible inability to close the mouth, difficulty in chewing, and trigeminal neuralgia (sharp pain in facial area). Facial (VII) - mixed nerve a mask-like appearance with minimal or no facial expression. Vestibulocochlear (VIII)sensory nerve Hearing loss, problems with balance, or both. Glossopharyngeal (IX) mixed nerve Difficulty in swallowing, unilateral loss of the gag reflex, and loss of taste and sensation from the posterior third of the tongue. Vagus (X) - mixed nerve Difficulty swallowing, paralysis of the velum, and voice problems. Spinal Accessory (XI) motor nerve Neck weakness, paralysis of the sternocleidomastoid, and consequent inability to turn heard as well as an inability to shrug the shoulders or raise the arm above shoulder level.

46 Autonomic Nervous System The autonomic nervous system (ANS) controls and regulates the internal environment of our bodies with it s two branches: Sympathetic- regulates the fight or flight, accelerates heart rate, dialates pupils, raises the blood pressure Parasympathetic- brings the body back to a state of relaxation, lowers blood pressure, slows the heart rate, increases activity within the stomach.

47 Central Nervous System

48 Central Nervous System Composition Spinal cord Enclosed within vertebral column Brain Pop Review: What is contained in the PNS? Enclosed in the skull Function Command center for planning, originating and carrying out messages Gathers info from the PNS Sends impulses that lead to actions

49 Roadmap Cerebrum Cerebellum Basal Ganglia Diencephalon Brainstem Reticular Activating System Pyramidal & Extrapyramidal Fibers Ventricles Blood Supply

50 CNS - Brainstem Connects spinal cord & brain Internal Structures: Longitudinal fiber tracts Cranial nerve nuclei Reticular formation External Structures: Midbrain Pons Medulla

51 CNS - Brainstem 1. Midbrain - Mesencephalon a. b. c. d. 2. Midbrain & pons connect cerebellum to other structures Controls postural & visual reflexes, eye movement Help connect brainstem to cerebellum Substantia nigra runs along it CN IV & CN III (not involved in speech) Pons - Metencephalon a. b. c. d. Movement info from cerebral hemispheres to cerebellum Contains descending motor fibers Involved in hearing & balance Houses nuclei for: i. V: trigeminal ii. VII: facial /medium_thumbs/cdr jpg

52 CNS - Brainstem 3. Medulla - Myelencephalon a. b. c. d. Uppermost part of spinal cord Centers that control bodily functions i. Breathing, digestion, HR and BP Motor information to CN nuclei i. VIII: vestibulocochlear ii. IX: glossopharyngeal iii. X: vagus iv. XI: accessory v. XII: hypoglossal Contains pyramidal tracts i. Decussation

53 CNS - Reticular Activating System AKA Reticular Formation Structure within midbrain, brainstem and upper spinal cord Integrates efferent motor info with afferent sensory info Mechanism of attention & consciousness Sleep-wake cycles, alertness

54 CNS - Diencephalon Between brainstem & cerebral hemispheres Thalamus Hypothalamus Regulates sensory information Receives motor info from cerebellum Consciousness & alertness Controls emotions Integrates ANS Third Ventricle CSF

55 CNS - Basal Ganglia Structures deep in brain, near thalamus Related to control of background movement & initiation of movement patterns Damage = movement disorders Corpus striatum I/AAAAAAAADVY/1bEQrvUhrBMYV-jisJQtSfiLHh8CkJTU gclcbgas/s1600/bg%2bchooses.jpg Lenticular nucleus Globus pallidus Putamen Caudate Nucleus Part of extrapyramidal system Substantia nigra is functionally related

56 CNS - Cerebellum The little brain - two hemispheres Cerebellar peduncles Helps coordinate and regulate impulses Both efferent & afferent Regulates Superior, middle & inferior Connect to brainstem Equilibrium Body posture Coordinate fine motor movements Very important for speech production Damage = ataxia

57 Brainstem, RAS, Diencephalon, Basal Ganglia & Cerebellum Review Questions

58 CNS - Cerebrum Cerebral cortex Wrinkled surface Gyrus - ridge Sucus - shallow valley Fissure - deep valley Main fissures/sulci Gray matter 6 layers billion neurons Longitudinal fissure Central sulcus/fissure Sylvian/lateral sulcus Four lobes 0dd1e0e5a3a9a719f2e70b

59 Frontal Lobe 1. Higher-level thinking, problem-solving conscious behavior, social interaction 2. Primary motor cortex a. b. c. d. 3. Supplementary motor cortex 4. Broca s area a. b. Precentral gyrus, anterior to central sulcus Contralateral motor control All muscles of body are connected to this strip Pyramidal system Motor movements for speech Anterior to primary motor cortex

60 Parietal Lobe Primary somatic sensory area Sensory cortex/strip Postcentral gyrus Supramarginal gyrus Integrates and controls sensory impulses Damage = conduction aphasia and/or agraphia Angular gyrus Damage = writing, reading and naming difficulties, sometimes transcortical sensory aphasia lan_1b.jpg

61 Occipital Lobe Primary visual cortex Not very relevant to speech and hearing Expect maybe for lip reading

62 Temporal Lobe Primary auditory cortex Superior temporal gyrus Receives sound stimuli from CN VIII Auditory association area Synthesizes info so it can be recognized Dominant hemisphere (L) Analyzes speech sounds Recognize words & sentences Nondominant hemisphere Primary auditory cortex & association area sometimes called Heschl s gyri Environmental noise & music Wernicke s area Posterior 2/3rds of superior temporal gyrus Comprehension of written & spoken language

63 Label the Brain Word Bank: Frontal Lobe Parietal Lobe Temporal Lobe Occipital Lobe Cerebellum Pons Medulla Central Sulcus Lateral Sulcus Precentral gyrus What else is this called? Postcentral gyrus What else is this called?

64 1. Lower Motor Neurons a. b. Upper & Lower Motor Neurons 2. Upper Motor Neurons a. b. c. 3. Cranial nerves Spinal nerves Within the CNS Pyramidal system i. Corticospinal tract ii. Corticobulbar tract Extrapyramidal system Summary a. b. UMN communicate with LMN LMN carry message to muscles

65 CNS - Pyramidal System Direct motor activation pathway Corticospinal tract Voluntary muscle movement Cerebral cortex spinal cord Spinal nerves innervate muscles Decussate at medulla anterior horn of vertebrae Corticobulbar tract Cerebral cortex brainstem (CN nuclei) Voluntary movement of speech muscles

66 CNS - Extrapyramidal System Indirect activation system Transmits impulses that control postural support needed for voluntary movement Anything not in the pyramidal system Subcortical nuclei, basal ganglia, substantia nigra (cerebellum contributes too probably) Includes pathways between these structures Influences lower motor neurons Helps maintain posture and tone Damage = involuntary movement disorders

67 Pyramidal & Extrapyramidal Review Questions

68 CNS - Connecting Fibers in the Brain Projection Fibers Association Fibers Commisural Fibers Connect cortex with subcortical structures like cerebellum, basal ganglia, brainstem Connect areas within the same hemisphere Connect corresponding areas of the 2 hemispheres Arcuate fasiculus connects Broca s area with Wernicke s area Corpus callosum connects hemispheres at their base Internal capsule contains concentrated PFs Intrahemispheric Originate in frontal lobe and form UPN system of pyramidal tract Afferent fibers fan out into corona radiata Damage = disconnection syndromes Interhemispheric

69 CNS - Cerebral Ventricles System of interconnected cavities filled with cerebrospinal fluid (CSF) CSF facts Made by choroid plexus Circulates and nourishes neural tissue Cushions brain Regulates pressure Removes waste Four ventricles Lateral (2) - inferior to corpus callosum Third - behind lateral at top of brainstem Fourth - between cerebellum and pons 3 & 4 connected by cerebral aqueduct

70 CNS - Protective Layers of the Brain 1. Layer of skin 2. Skull bones 3. Layers of tissue - meninges a. b. c. 4. Dura mater - thick and tough Arachnoid - thin and delicate, vascularized Pia mater - adheres to brain surface Where is the CSF? a. b. Between arachnoid & pia mater Subarachnoid space

71 CNS - Central Blood Supply Anterior System Posterior System Aorta common carotid arteries Aorta vertebral arteries Carotid arteries split into internal & external branches Vertebral arteries join & become basilar artery External branch supplies face Internal divides into anterior & middle cerebral arteries Basilar artery divides into posterior cerebral arteries Middle supplies lateral surface of cortex Anterior supplies medial surfaces of hemispheres Supply inferior surface of brain

72 CNS - Circle of Willis Base of brain Carotid & vertebral arteries join Circle completed by communicating arteries Blockage Below the circle - minimal damage Above the circle -bad news

73 Another visualization of Circle of Willis

74 Fibers, Ventricles, Layers, CSF & Blood Supply Questions

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