Neck Region PA 544 Clinical Anatomy

Anterior Surface

Triangles at Surface

Hyoid 1.C3 level 2.Suprahyoid muscles 3.Infrahyoid muscles

Vertebral Column

Intervertebral disc

Vertebra Parts

C1 & C2

Cervical Vertebra

Typical Cervical Vertebra

Spinal Cord Receives and generates signals to body through the spinal nerves

Cord in Spinal Canal Dorsal Root Ganglion Denticulate Ligament Posterior Median Sulcus Posterior Root Anterior Root Spinal Nerve

Spinal Cord (X.S.)

Spinal Nerve Anatomy

Functional Arrangement of SC Ascending and descending pathways

Ascending Pathways

Descending Pathways

Cervical Plexus Serves neck and diaphragm

Brachial Plexus and pectoral nerves

Brachial Plexus Innervates most of the arm and some of the body wall.

Spinal Cord Segments 4 segments: Cervical, Thoracic, Lumbar, and Sacral (only 1 coccygeal nerve) 31 pairs of spinal nerves

Cervical Segment

Neck Fascia Prevertebral fascia Alar fascia Pretracheal fascia Investing fascia Superficial fascia

Platysma

SCM Trapezius SCM and Trapezius

Cervical Triangles Posterior Triangle Anterior Triangle

Posterior Triangle Supraclavicular triangle Occipital triangle

Superficial and Deep Posterior Triangle Platysma Nerve Point of Neck Ext. jugular v. SCM Accessory n. Prevertebral fascia Brachial plexus Scalenes Phrenic n. Splenius Levator scapulae

Supraclavicular Triangle Brachial Plexus Subclavian vessels SCM

Anterior Triangles Submental Carotid Submandibular Muscular

Muscular Triangle

Muscles of Triangle Sternohyoid Sternothyroid Thyrohyoid Thyroid

Thyroid Location

Accessory Thyroid gland Accessory thyroid along thyroglossal duct

Pyramidal lobe (50% of people have this lobe structure)

Thyroid Follicle (follicular cells  thyroxine) Parafollicular cells  calcitonin

T 3 & T 4

Control of Thyroxine Secretion Short loop Long loop

Thyroid Malfunction Hypothyroidism Endemic goiters –due to iodine deffeicency Cretinism –  thyroxine in child results in  growth (dwarf) and severe mental retardation Myxedema –  thyroxine in adult, leads to swelling of tissues plus other symptoms

Cretinism

Thyroid Malfunction Hyperthyroidism Toxic goiters (Graves disease) –Ab may stimulate thyroid without negative feedback control Exophthalmos –symptom present in many hyperthyroid patients

Parathyroid Location

PTH Actions Stimulates resorption of bone   Ca + and PO 4 - in blood Stimulates Ca + absorption in intestine (active Vit. D 3 necessary for Ca + absorption) Stimulates Ca + reabsorption and PO 4 - excretion in kidney Stimulates Vit. D 3 formation (skin) and activation (kidney) Vital for life

Thyroid cartilage Cricoid cartilage Epiglottis Arytenoid cartilage Laryngeal Cartilages Hyoid (posterior) (anterior)

Voice Box Vocal fold Vestibular fold Ventricle

CN X: supply to laryngeal muscles Recurrent Laryngeal n. (motor to all other laryngeal muscles) External Laryngeal n. (motor to inf. Pharnygeal constrictor and the cricohyoid) Internal Laryngeal n. (sensory & autonomic) Inf. Vagal ganglion

Submental Triangle Digastric Mylohyoid -contains submental lymph nodes

Carotid Triangle Digastric (posterior belly) SCM Ansa cervicalis Common carotid a. Internal carotid a. External carotid a. IJV Omohyoid

Ext. Carotid Branches Common Carotid IJV Int. carotid Ext. carotid Sup. Thyroid Facial Lingual Occipital Post. Auricular Maxillary Superficial Temporal Asc. Pharyngeal (not show) Ansa cervicalis Hypoglossal n.

External carotid (isolated) Occipital Post. Auricular Superficial Temporal Maxillary Sup. Thyroid Facial Lingual Asc. Pharyngeal Note: Internal carotid has NO neck branches.

Carotid bodies

IJV Sup. Bulb of IJV Inf. Bulb of IJV IJV Facial Sup. Thyroid

Lymph nodes of neck Deep Cervical Lymph nodes (most located in carotid sheath)

Submandibular Triangle Submandibular glands Digastrics

Submandibular Lymph nodes

Pharynx Function: deglutition Mucosa: Str. Squamous Muscularis: Skeletal

Oro- and nasopharynx Pharyngeal tonsil Pharyngeal recess Palatine bone Soft palate Uvula Lingual Tonsil Tubal tonsils (small holes) Pharyngotympanic (Eustachian) tube Salpingopharyngeal fold Tonsillar cleft Palatoglossal arch Palatopharyngeal arch

Longitudinal pharyngeal muscles Palatopharyngeus

Tonsils Pharyngeal Tonsil

Pharyngeal Constrictors Superior Middle Inferior

Peristalsis

Deglutition (Swallowing)

Fluid Drinking

Deglutition (cont’d)

Laryngopharynx Epiglottis Piriform recess