Revision II Anatomy of the Neck (11-12-2024) - PDF

REVISION 11.12.2024 Panagiotis Karanis, Professor of Anatomy UNic Medical School Anatomy of the Neck  Respiratory System  The surface anatomy of the neck The differential diagnosis of lumps...

REVISION 11.12.2024 Panagiotis Karanis, Professor of Anatomy UNic Medical School Anatomy of the Neck  Respiratory System  The surface anatomy of the neck The differential diagnosis of lumps in the neck and the effective clinical and surgical management of pathological lesions in the neck require a sound knowledge of the surgical anatomy of the head and neck. By pressing the jaw laterally against the resistance of one’s hand, the opposite sternocleidomastoid is tensed. This muscle helps define the posterior triangle of the neck, bounded by sternocleidomastoid, trapezius and the clavicle, and the anterior triangle, defined by The triangles of the neck sternocleidomastoid, the mandible and the midline (Figure).  Platysma muscle Lying immediately deep to the subcutaneous fat, on either side of the anterior midline, is the platysma, a relatively thin but wide sheet of muscle. Platysma. The thin platysma muscle spreads subcutaneously like a sheet, passes over the clavicles, and is pierced by cutaneous nerves. The platysma (G. flat plate) is supplied by branches of the facial nerve, CN VII. The platysma is a feature of the anterolateral part of the neck and does not extend to the back of the neck. Above the level of the hyoid, the medial borders of the right and left platysma muscles are contiguous, whereas, below the hyoid level, they are separated from each other by an interval of 2.5 cm.  Neck fascial layers Deep to the skin of the neck is the superficial fascia or panniculus adiposus, which is essentially a layer of subcutaneous fat, more or less homogeneous. The degree of adiposity in this layer varies between individuals; it also varies, to some extent, between the anterior and posterior aspects of the neck in the same individual, being generally somewhat thinner in the front of the neck than in the back.  Cervical regions. Triangles and their borders Between the cranium (mandible anteriorly and occipital bone posteriorly) and clavicles, the neck is divided into four major regions based on the usually visible and/or palpable borders of the large and relatively superficial SCM and trapezius muscles, which are contained within the outermost (investing) layer of deep cervical fascia.  The anatomy of the neck The differential diagnosis of lumps in the neck and the effective clinical and surgical management of pathological lesions in the neck require a sound knowledge of the surgical anatomy of the head and neck. In the midline, from above down, can be felt (Fig): 1 the hyoid bone – at the level of C3; 2 the notch of the thyroid cartilage – at the level of C4; 3 the cricothyroid ligament – important in cricothyroid puncture; 4 the cricoid cartilage – terminating in the trachea at the level of C6; 5 the rings of the trachea, over the 2nd and 3rd of which lies the isthmus of the thyroid gland (sometimes palpable); 6 the suprasternal notch. Structures palpable on the anterior aspect of the neck, together with their corresponding vertebral levels.  The fascial compartments of the neck The topographical arrangement of the fascial and muscular planes in the anterior aspect of the neck is fundamental to accuracy in the clinical diagnosis of neck lumps, besides being an essential prerequisite to safety and precision in neck surgery. The deep fascia can be classified into four parts: investing layer of deep cervical fascia, pretracheal fascia, prevertebral fascia and carotid sheaths (right and left). (a) Transverse section of the neck through C6, showing the fascial planes and also the contents of the pretracheal fascia (or ‘visceral compartment of the neck’).  The fascial compartments of the neck Immediately deep to the platysma is the investing layer of deep cervical fascia, the most superficial of the multiple layers of the deep cervical fascia. It invests the neck like a collar. All the cervical viscera, major blood vessels and nerves of the neck and all the cervical muscles (with the sole exception of the platysma) come to lie within the sweep of the investing layer of deep cervical fascia. The deepest layer of the deep cervical fascia is the prevertebral fascia, a relatively dense layer that covers the anterior aspects of the prevertebral musculature and the cervical vertebral column. The prevertebral fascia passes across the vertebrae and prevertebral muscles behind the oesophagus, the pharynx and the great vessels. Above, it is attached to the base of the skull. Laterally, the fascia covers the scalene muscles together with the phrenic nerve, as this lies on scalenus anterior, and the emerging brachial plexus and subclavian artery. (a) Transverse section of the neck through C6, showing the These structures carry with them a sheath formed from fascial planes and also the contents of the pretracheal fascia the prevertebral fascia, which becomes the axillary (or ‘visceral compartment of the neck’). sheath. (b) Computed tomography (CT) scan through the C6 level; compare this with (a).  The fascial compartments of the neck The entire thyroid gland is enveloped in a further layer of deep cervical fascia termed the pretracheal fascia. The pretracheal fascia is itself firmly adherent to the front of the upper trachea behind the isthmus, and, elsewhere, to the sides of the cricoid and thyroid cartilages. (a) Transverse section of the neck through C6, showing the fascial planes and also the contents of the pretracheal fascia (or ‘visceral compartment of the neck’). Carotid sheath What is the Ansa cervicalis ?  Cricothyroid LARYNX INTRINSIC MUSCLES OF Posterior Transverse Tenses arytenoid crico-arytenoid Superior laryngeal nerve Adduct all Abdduct cords (All else recurrent laryngeal) The actions of the intrinsic laryngeal muscles are easiest to understand when they are considered as functional groups: adductors and abductors, sphincters, and tensors Lateral and relaxers Thyro-arytenoid crico-arytenoid whisp Oblique arytenoid Relaxes Adduct all Adduct cords only VARIATIONS IN SHAPE OF RIMA GLOTTIDIS Vessels, nerves, and lymph nodes of the larynx Laryngeal branches of the right nerve (CN X) The thyroid gland The thyroid is made up of : 1 the isthmus – overlying the 2nd and 3rd rings of the trachea; 2 the lateral lobes – each extending from the side of the thyroid cartilage downwards to the 6th tracheal ring; 3 an inconstant pyramidal lobe projecting upwards from the isthmus, usually on the left side, which represents a remnant of the embryological descent of the thyroid.  Development The thyroid develops from a bud that pushes out from the floor of the pharynx; this outgrowth, termed the thyroglossal duct, then descends to its definitive position in the neck. The lower end of the thyroglossal duct proliferates to become the thyroid gland, while the rest of the thyroglossal duct disintegrates and disappears. The origin of the thyroid is, however, commemorated by the foramen caecum, the midline punctum at the junction of the middle and posterior thirds of the tongue, and by the inconstant pyramidal lobe on the isthmus. The descent of the thyroid, showing possible sites of ectopic thyroid tissue or thyroglossal cysts, and also the course of a thyroglossal fistula. (The arrow shows the further descent of the thyroid that may take place retrosternally into the superior mediastinum.) See you in 2025 Which are the muscles of respiration (inhalation and exhalation)  Ribs, Costal Cartilages and Intercostal Spaces Classification of the ribs  True Vertebro - sternal ribs (1st-7th ribs);  False (Vertebro - chondral) ribs; (8th, 9th, and usually 10th ribs)  Floating (vertebral, free) ribs; (11th, 12th, and sometimes 10th ribs) Ribs have an attachment to the sternum, except for the floating ribs. What is the classification of ribs? A.True ribs 1-5; False ribs 5-8; Floating ribs 9-11. B. True ribs 1-9; Floating ribs 10-12. C.True ribs 1-9; False ribs 10-12. D.True ribs 1-7; False ribs 8-10; Floating ribs 11-12. E. True ribs 1-10; False ribs 11-12. A.True ribs 1-5; False ribs 5-8; Floating ribs 9-11. B. True ribs 1-9; Floating ribs 10-12. C.True ribs 1-9; False ribs 10-12. D. True ribs 1-7; False ribs 8-10; Floating ribs 11-12. E. True ribs 1-10; False ribs 11-12.  Trachea Fibrocartilagenous tube Tracheal cartilages (incomplete) D 2,5 cm adults C6 to T4-5 IV disc sternal angle Right and Left bronchi Brachiocephalic trunk related to rt side of trachea Deviation of trachea from midline signals Pathological process Usually an aspirated foreign body is located in the right bronchus. What are the characteristics of the right primary bronchus that support this assertive? A. The right primary bronchus is longer and less angled than the left primary bronchus. B. The right primary bronchus is longer and more angled than the left primary bronchus. C. The right primary bronchus is wider and less angled than the left primary bronchus. D. The right primary bronchus is wider and more angled than the left primary bronchus. E. The right primary bronchus is wider and shorter than the left primary bronchus. Pleural cavity Each lung is enclosed in a serous pleural sac Serous pleural fluid Parietal Pleura Costal Mediastinal Diaphragmatic Cervical Visceral pleura (hilum of lung)  Lungs Apex Base 2 or 3 lobes created by 1 or 2 fissures 3 surfaces (costal, mediastinal, diaphragmatic) Right lung: right oblique and horizontal fissure 3 lobes: superior, middle, inferior Left lung: left oblique fissure 3 borders (anterior, 2 lobes: superior, inferior inferior, posterior) Which are the major vessels responsible for blood supply to the lungs? A.Aorta and Inferior Vena Cava. B. Bronchial arteries and veins. C.Coronary arteries and veins. D.Lung arteries and veins. E. Pulmonary arteries and veins. A.Aorta and Inferior Vena Cava. B.Bronchial arteries and veins. C.Coronary arteries and veins. D.Lung arteries and veins. E. Pulmonary arteries and veins.  Supplementum Respiratory System 1 UNIC MD-6 Anatomy Station Guide (student version) (cont.) Station 2: The Intercostal Space and Neurovascular Supply of the Thoracic Wall - In addition to the intercostal nerves, several other nerves supply the thoracic wall. Identify the following nerves:  Long thoracic (Serratus anterior muscle)  Medial and Lateral pectoral (Pectoralis major muscle)  Dorsal scapular (levator scapulae, the rhomboid major, and the rhomboid minor muscles)  Thoracodorsal (Latissimus dorsi muscle) (cont.) Station 2: The Intercostal Space and Neurovascular Supply of the Thoracic Wall Sympathetic Chain - Identify the thoracic portion of the sympathetic chain in the posterior mediastinum. - Thoracic nerve supply to parietal structures comes from rami communicantes. - Ganglia associated with levels T1-T5 supply cardiac branches to the heart. - Thoracic splanchnic nerves arise from it and pass posterior to the diaphragm- they give abdominal supply - T5-T9 form the greater splanchnic nerve - T10-T11 form the lesser splanchnic nerve - T12 forms the least splanchnic nerve  SUPPLEMENTUM FOR THE DIAPHRAGM  SUPPLEMENTUM FOR THE DIAPHRAGM  SUPPLEMENTUM FOR THE DIAPHRAGM  SUPPLEMENTUM FOR THE DIAPHRAGM Levels and the diaphragm Inferior vena cave T8 Oesophagus T10 Aorta T12  Station 2: The Intercostal Space and Neurovascular Supply of the Thoracic Wall - What structures pass through the openings of the diaphragm? At what vertebral levels?  Kidney and Urinary System Internal appearance of kidneys – Renal cortex (Most superficial layer) – Renal medulla Renal pyramids (drain into the calyces) Renal lobe – Renal pelvis Calyces (drains into renal pelvis) – Ureter  RENAL ARTERIOGRAM RENAL SEGMENTS & SEGMENTAL ARTERIES (1-5, segmental arteries)  Microscopic Anatomy of the Kidneys GLOMERULUS WITH A CAPSULE = RENAL CORPUSCLE PROXIMAL CONVOLUTED TUBULE LOOP OF HENLE – DESCENDING LIMB Thick portion Thin portion – ASCENDING LIMB Thick portion Thin portion DISTAL CONVOLUTED TUBULE COLLECTING DUCT Clinical Relevance: Horseshoe Kidney A horseshoe kidney is where the two developing kidneys fuse into a single horseshoe-shaped structure. This occurs if the kidneys become too close together during their ascent from the pelvis to the abdomen – they become fused and consequently ‘stuck’ underneath the inferior mesenteric artery. Drained by 2 ureters, usually asymptomatic, although it can be prone to obstruction. Q Example During an abdominal imaging study in young nine year old refuge man, the radiologist found that the poles of his kidneys were fused inferiorly. Which arteria prevents the physiological ascend of the kidneys during embryological development? A. Sigmoid B. Right colic C. Superior mesenteric D. Inferior mesenteric E. Middle colic Q Example During an abdominal imaging study in young nine year old refuge man, the radiologist found that the poles of his kidneys were fused inferiorly. Which arteria prevents the physiological ascend of the kidneys during embryological development? A. Sigmoid B. Right colic C. Superior mesenteric D. Inferior mesenteric E. Middle colic  Ureters are 25-30 cm long that carry urine from the Normal constrictions (3) of ureters kidneys to the urinary 1. Junction of ureters and renal pelvis bladder (Peristalsis !). 2. Cross the brim of the pelvic inlet The ureters are 3. Passage the wall of urinary bladder retroperitoneal   Kidney and Urinary System  Anatomical details on urinary bladder and parts of the urethra, urinary catheters.  Gastrointestinal System I-III Opposite the upper 2end molar tooth, the duct of the parotid gland opens out into the vestibule, secreting salivatory juices. Amylase (Ptyalin), breakdown starch to glucose and oligosaccharides. Mouth Sensation; Mechanical form the bolus digestion; Mix, move & Parotid gland Salivary glands: chemical digestion Tongue Tongue  Chorda tympani The chorda tympani is a branch of the facial nerve that originates from the taste buds in the front of the tongue, runs through the middle ear, and carries taste messages to the brain. The pharynx Has 3 constrictors Swallowing (deglutition) Only passageway No digestion or absorption Opening of pharyngotympanic tube (Eustachian tube, serves to equalize the barometric pressure/ way of infections/ Inflammation of middle ear leads to: Otitis media (ear pain, fever). Nasopharynx (Epi-pharynx) Oropharynx Adenoitis (Meso-pharynx) Epiglottitis Pharyngitis Laryngopharynx (Hypo-pharynx) Revise the Swallowing reflex Anterior wall of the pharynx Anterior wall of the pharynx Stomach Functions 1. Mixes the saliva, food & gastric juice, which secrets to form Pylorospasm the Chyme Pylorostenosis 2. Gastric juice -HCl (kills bacteria & denature proteins); -Pepsin (begins to digest Proteins); Peptic diseases ulcer: -intrinsic factor Helicobacter pylori (absorbs B12); -Gastic lipase (aids Ulcer can cause digestion of proteins) gastric perforation 3. Reservoir for food The word pylorus comes from Greek πυλωρός. Pylorus in Greek means "gatekeeper", related to "gate" (Greek: pyle). Arteries of the stomach  The biliary tree Img : gallstoneflush.com The Pringle maneuver is a common surgical technique that temporarily clamps off blood flowing into the liver.  Visceral surface of the liver The 4 anatomical lobes of the liver 2 sagittaly fissures, form the letter H on the visceral surface. The right sagittal fissure (fossa for gallbladder and groove of vena cava). The umbilical (left sagittal) fissure formed by fissure for round ligament and the fissure for ligamentum venosum. Ligamentum venosum: remnant of the fetal ductus venosus, shunted blood from the umbilical vein to the IVC. Fossa for the gallbladder & porta hepatis where Ligamentum teres (round) hepatis: remnant of vessels: (hepatic portal vein, hepatic artery, the umbilical vein, carried well-oxygenated lymphatics), the hepatic nerve plexus, and hepatic blood and nutrient rich blood from the placenta to the fetus. ducts that supply and drain.  The ligaments of the liver 1- The Falciform ligament of liver 2- The Ligamentum teres hepatis 3- The Coronary ligament 4The Right triangular ligament 5The Left triangular ligament 6The Hepatogastric ligament 7The Hepatoduodenal ligament 8The Ligamentum venosum  Coronary ligament the area between the upper and lower layer of the coronary ligament is the bare area of the liver which is in contact with the diaphragm; Left and right triangular ligaments formed by left and right extremity of coronary ligament  Blood supply of the liver The liver receives blood from two sources: arterial blood from the hepatic artery (it divides into left and right branches) venous blood is carried to the liver by the portal vein Three main hepatic veins (lt, mid, rt) drain into the inferior vena cava. Celiac Trunk  2 borders 2 extremities The visceral surface of the spleen 2 surfaces  Notches of the superior border  Concavities on the visceral surface  Covered by visceral peritoneum Connected with: stomach (greater curvature) with Lig. gastro-splenicum) left kidney with Lig. spleno-renale Splenic hilum in contact with pancreas tail Blood supply: splenic artery (A. splenica) splenic vein (V. splenica) Spleen – Venous drainage Img : Radiologypics.com Img : Radiologypics.com Duodenum, Jejunum & Ileum Relationships and parts of duodenum Duodenum  Ampulla  Major and minor duodenal papillae  Plicae circulares  Suspensory muscle of the duodenum (Ligament of Treitz). Mesentery & distinctive features of Jejunum & Ileum Distinctive features of jejunum and ileum Large intestine Large Intestine Parts  Caecum  Appendix  Ascending colon  Transverse colon  Descending colon  Sigmoid colon  Rectum  Anal canal The colon has four parts—ascending (secondarily retroperitoneal), transverse (intraperitoneal), descending (secondarily retroperitoneal), and sigmoid—that succeed one another in an arch. The colon encircles the small intestine, the ascending colon lying to the right of the small intestine, the transverse colon superior and/or anterior to it, the descending colon to the left of it, and the sigmoid colon inferior to it. The sigmoid colon, characterized by its S- shaped loop of variable length, links the descending colon and the rectum. The sigmoid colon extends from the iliac fossa to the third sacral (S3) vertebra, where it joins the rectum. The termination of the teniae coli, approximately 15 cm from the anus, indicates the rectosigmoid junction. The rectum is the fixed (primarily retroperitoneal and subperitoneal) terminal part of the large intestine. It is continuous with the sigmoid colon at the level of S3 vertebra. The junction is at the inferior end of the mesentery of the sigmoid colon. The rectum is continuous inferiorly with the anal canal. Characterized by  Omental appendices  Teniae coli (longitudinal coat: 2 mesocolic tenia, omental tenia, free tenia) From base of appendix to rectosigmoid junction  Haustra (sacculations of the wall between the teniae)  Large caliber  APPENDIX (vermiform appendix)  Blind intestinal diverticulum 6-10 cm  Contains lymphoid tissue  Mesoappendix  Usually retrocoecal Arterial supply to the intestine Venous drainage - Intestine Portal systemic anastomoses in which portal venous system communicates with the systemic venous system, are formed in the submucosa of the inferior esophagus, in the submucosa of the anal canal, in the peri-umbilical region, and on the posterior aspects (bare areas) of secondarily retroperitoneal viscera, or the liver. When portal circulation through the liver is diminished or obstructed because of liver disease or physical pressure from a tumor, for example, blood from the gastrointestinal tract can still reach the right side of the heart through the IVC by way of these collateral routes. Portal – Systemic Anastomoses Here, the portal tributaries are darker blue and systemic tributaries are lighter blue. A–D indicate sites of anastomoses.  The volume of the blood forced through the collateral routes may be excessive, resulting in potential fatal varices (abnormally dilated vein) if the obstruction is not surgically bypassed. Clinical: Oesophageal bleed Rectum Anatomy of the anal canal, including relevant musculature Anatomy of the anatomic and surgical anal canal Structures that can be palpated via a rectal examination in the male and the female The prostate is examined for enlargement and tumors (focal masses or asymmetry) by digital rectal examination (Fig.). The size and disposition of The palpability of the prostate depends on the fullness of the uterus may be the bladder. The malignant prostate feels hard and often examined by bimanual irregular. palpation (Fig. A). The uterus can be further stabilized through rectovaginal examination, which is used if examination via the vagina alone does not yield clear findings (Fig. B) Hindgut: Rectum  Male vs. Female Relations Clinical Diverticulosis Volvulus  Polyposis The polyp (ancient Greek πολύπους = "polypede") HEMORRHOIDS Haemorrhoids   Endocrine System  Endocrine organs, its function and blood supply Q Example The thyroid is supplied with blood by different arteries. Which artery from the following does supply the thyroid and it needs to be ligated by thyroid surgery? A. Thyrocervical trunk B. Descending thoracic aorta C. External carotid artery D. Internal carotid artery E. Subclavian artery  Hematopoetic & Reticuloendothelial system  Waldeyer’s tonsillar ring, Lymph drainage, Edema, Thoracic duct begin and termination, Lymph node function, Sentinel lymph node. Thank you