ana lab

• Neck


  Extends from the base of the cranium and inferior border of the mandible to the thoracic inlet
• Neck muscles


  • Move the neck and head
  • Move the hyoid, larynx, or tongue during speech and swallowing
• Muscles of the neck

  • Trapezius muscle
  • Scalene muscles
  • Sternocleidomastoid muscle
  • Sternohyoid muscle
  • Sternothyroid muscle
  • Omohyoid muscle
  • Digastric muscle
  • Platysma
• Trapezius muscle


  • Broad, flat, superficial muscle extending from the cervical to thoracic region on the posterior aspect of the neck and trunk
  • Origin: Medial 3rd of the superior nuchal line; external occipital protuberance, nuchal ligament and spinous process of C7-T12 vertebrae
  • Insertion: Lateral 3rd of the clavicle, acromion, and spine of scapula
  • Blood Supply: Transverse cervical artery
  • Nerve Supply: Spinal root of accessory nerve (CXll; motor) and Cervical nerves (C3and C4) pain and proprioception
  • Function: Allows and supports the spinal column to remain erect when standing, plays an important role in shoulder movements of the head, elevating and depressing the shoulders and internally rotating the arm

  
• Scalene muscles


  • Found on the lateral side of the neck, bounded by the sternocleidomastoid and turn the head to the right (Anterior, middle and posterior)
  • Origin: Transverse process of the cervical vertebrae
  • Insertion: Ribs 1 and 2
  • Action: Flexes and rotates neck, elevates ribs 1&2
  • Innervation: Spinal Nerve C4-8
• Sternocleidomastoid muscle


  • Muscles that rotate the head in a unique way
  • Origin: Manubrium and medial clavicle
  • Insertion: Mastoid process, superior nuchal line
  • Action: One: rotates and extends neck, Both: flex neck
  • Innervation: Accessory Nerve (Xl)
• Sternohyoid


  • Anchors the stable part of the muscle
  • Origin: Manubrium of sternum
  • Insertion: Hyoid
  • Action: Depresses the hyoid bone
  • Innervation: Spinal Nerves C1-C3
• Sternothyroid


  • Anchors the stable part of the muscle
  • Origin: Manubrium of sternum
  • Insertion: Thyroid cartilage of the larynx
  • Action: Depresses the larynx
  • Innervation: Spinal nerve C1-3
• Omohyoid


  • OMO means shoulder
  • Origin: Superior border of the scapula
  • Insertion: Hyoid bone
  • Action: Depresses and fixes hyoid
  • Innervation: Spinal Nerve C1-3
• Digastric muscle


  • Muscle that depresses the mandible, inserted into the hyoid that is responsible for the movement of the tongue for speech and swallowing
  • Origin: Mastoid process of the temporal (posterior belly)
  • Insertion: Mandible near the midline (Anterior Belly)
  • Action: Elevates, protracts, and retracts hyoid, depresses the mandible
  • Innervation: Trigeminal Nerve (V) and Facial nerve(Vll)
• Mylohyoid muscle


  • Broad muscle of the floor of the mouth that pushes the tongue superiorly when swallowing
  • Origin: Body of the Mandible
  • Insertion: Hyoid
  • Action: Elevates the floor of the mouth and tongue
  • Innervation: Trigeminal Nerve
• Pharynx


  A 12-14 cm long musculomembranous tube shaped like an inverted cone, extending from the cranial base to the lower border of the cricoid cartilage, with varying width depending on muscle tone
• Pharynx components


  • 3 circular contractors
  • 3 longitudinal elevators
• Pharynx blood supply


  Branches of the external carotid artery, particularly the ascending branches of the facial artery, maxillary artery and lingual artery
• Nasopharynx


  Lies above the soft palate and behind the posterior nares, allowing free respiratory passage between the nasal cavity and the nasopharynx
• Pharyngeal tonsils or adenoid


  A median mass of mucosa-associated lymphoid tissue situated in the roof and posterior wall of the nasopharynx, with a truncated pyramid shape often with a vertically oriented median cleft
• Oropharynx


  Extends from below the soft palate to the upper border of the epiglottis, opening the mouth through the oropharyngeal isthmus demarcated by the palatoglossal arch and facing the pharyngeal aspect of the tongue
• Soft palate


  A mobile flap from the posterior border of the hard palate, dividing the oral and nasal parts of the pharynx
• Oropharynx


  • Extends from below the soft palate to the upper border of the epiglottis
  • Opens the mouth through the oropharyngeal isthmus demarcated by the palatoglossal arch and faces the pharyngeal aspect of the tongue
• Soft palate


  • Mobile flap from the posterior border of the hard palate
  • Extends down and back between the oral and nasal parts
• Larynx


  • Air passage, a sphincter and an organ of phonation
  • Extends from the tongue to the trachea
  • At rest it lies opposite the 3rd and 6th cervical vertebrae in adult males, somewhat higher in females and children
• Laryngeal skeletal framework


  • Formed by a series of cartilages interconnected by ligaments and fibrous membranes
  • Hyoid bone is attached to the larynx
• Epiglottis


  • Leaf-like plate of elastic fibrocartilage
  • Projects obliquely upwards behind the tongue and hyoid body and in the front of the laryngeal inlet
  • Functions: During swallowing, the hyoid bone moves upwards and forwards, and it is bent posteriorly as a result of passive pressure from the base of the tongue, and active contraction of the aryepigllotic muscles
  • Not essential for swallowing
  • Not essential for respiration or phonation
• Brain


  • Located in the cranial cavity of the skull
  • Weighs approximately 1.4 kilograms (3 pounds)
  • Derived from 3 embryonic parts that develop into more specific parts
  • Cranial nerves are associated with the brain
  • Gray matter is extensive and forms the cerebral cortex in which the most active and integrative process
• Meninges


  • Dura mater - tough, dense connective tissue sheath that encircles the brain and series shelves that extends into the brain
  • Arachnoid Mater - thin membrane that resembles a spider's web
  • Subdural space - deep space to the dura
  • Subarachnoid space - contains the cerebrospinal fluid (CSF)
  • Pia Mater - deepest layer, a membrane directly on the outer surface of the brain
• Major regions of the brain

  • Prosencephalon - develops the FOREBRAIN which contains the cerebrum, and diencephalon
  • Mesencephalon - develops the MIDBRAIN which small in in adult brain
  • Rhombencephalon or HINDBRAIN - develops into Pons, Medulla Oblongata, Cerebellum
• Ventricles


  • Lateral Ventricles - occupies each cerebral hemisphere
  • Third Ventricle - located at the thalamus and receives CSF from the choroid plexus and drains into the fourth ventricle by the cerebral Aqueduct
  • Septum Pellucidum - wall that separates the lateral ventricle from the third ventricle
  • Internal hydrocephalus - condition wherein the duct occludes and produces more fluid and put pressure on the nervous tissue
• Midbrain


  • Small area posterior to diencephalon
  • Cerebral peduncles occupy the area superior to the pons
• Hindbrain


  • Pons - relay center shunting information from the inferior regions of the body through the thalamus and to other areas of the brain
  • Respiratory Centers - located in pons that are involved in controlling the breathing rate
  • Medulla Oblongata - presence of respiratory rate, center for heart rate and other vital centers
  • Decussation of the Pyramids - area where motor tracts cross over the medulla oblongata
• Cranial nerves


  • Olfactory
  • Optic
  • Oculomotor
  • Trochlear
  • Trigeminal
  • Abducent
  • Facial
  • Vestibulocochlear
  • Glossopharyngeal
  • Vagus
  • Spinal accessory
  • Hypoglossal

  
• Cranial nerves


  • Emerge directly from the brain and primarily innervate structures in the head and neck
  • Named numerically and serve diverse functions, including sensory, motor, and autonomic roles
  • Transmit information between the brain and different parts of the body, contributing to functions such as vision, hearing, taste, smell, and facial movements
• Olfactory nerve


  • Sensory nerve that contributes to the sense of smell in human beings
  • Carries the information from the nasal epithelium to the olfactory center in brain
• Optic nerve


  • Sensory nerve that transforms information about vision to the brain
  • Supplies information to the retina in the form of ganglion cells
• Oculomotor nerve


  • Motor nerve that supplies to different centres along the midbrain
  • Functions include superiorly uplifting the eyelid, superiorly rotating the eyeball, construction of the pupil on the exposure to light and operating several eye muscles
• Trochlear nerve


  • Motor nerve that supplies to the midbrain and performs the function of handling the eye muscles and turning the eye
• Trigeminal nerve


  • Largest cranial nerve and performs many sensory functions related to the nose, eyes, tongue and teeth
  • Further divided in three branches: ophthalmic, maxillary and mandibular
  • Mixed nerve that performs sensory and motor functions in the brain
• Abducent nerve


  • Motor nerve that supplies to the pons and performs the function of turning the eye laterally
• Facial nerve


  • Motor nerve responsible for different types of facial expressions
  • Performs some functions of sensory nerve by supplying information about touch on the face and senses of tongue in mouth
  • Present over the brain stem

  
• Vestibulocochlear nerve


  • Motor nerve that provides information related to balance of head and sense of sound or hearing
  • Carries vestibular as well as cochlear information to the brain
• Glossopharyngeal nerve


  • Sensory nerve that carries sensory information from the pharynx (initial portion of throat) and some portion of tongue and palate
  • Carries information about temperature, pressure and other related facts
  • Covers some portion of taste buds and salivary glands
  • Performs some motor functions such as helping in swallowing food