Final Oral Anatomy.docx

**Inguinal Triangle** - Inguinal TRIANGLE - IS THE SPACE OF DIRECT HERNIA and contain NOTHING - Medial → linea semilunaris - inferolateral → inguinal ligament - superior lateral → inferior epigastric artery **Inguinal Canal** - Is a oblique passage through lower part of anterior a...

**Inguinal Triangle** - Inguinal TRIANGLE - IS THE SPACE OF DIRECT HERNIA and contain NOTHING - Medial → linea semilunaris - inferolateral → inguinal ligament - superior lateral → inferior epigastric artery **Inguinal Canal** - Is a oblique passage through lower part of anterior abdominal wall. - The inguinal canal starts at the deep inguinal ring in transversalis fascia and end at the superficial inguinal ring in aponeurosis of external oblique Deep inguinal is oval and superficial is triangular - ANTERIOR WALL → aponeurosis of external oblique - POSTERIOR WALL → transversalis fascia and medial third by CONJOINED tendón - INFERIOR WALL → inguinal ligament and medial end of lacunar ligament - SUPERIOR WALL → arch of the lowest fibers of internal oblique and transversus abdominis muscle - In Females: Round ligament, genital branch of genitofemoral nerve, branch of ilioinguinal nerve - In males: Spermatic cord, genital branch of genitofemoral nerve, branch from ilioinguinal nerve - DEEP INGUINAL RING lies in the level of midinguinal point, it is formed when the process vaginalis invaginates the transversalis fascia. (indirect hernia) - MEDIAL → it is related to inferior epigastric vessels - SUPERIOR LATERAL → by arch fibers from transversalis fascia - SUPERFICIAL INGUINAL RING formed by aponeurosis of external oblique (is palpebrae in superior lateral to the pubic tubercle) (Place of direct hernia) (also indirect hernia) - BASE → pubic crest - LATERAL → medial and lateral crus from aponeurosis of external oblique - SUPERIOR MEDIAL → intercrural fibers from inguinal ligament - Anterior crus = intercrural fibers - Posterior crus = reflected inguinal ligament - Lateral crus = lateral fibers of aponeurosis - Medial crus = medial fibers of the aponeurosis **Right Atrium** - The right atrium receives deoxygenated blood from: - Superior vena cava - Inferior vena cava - Coronary sinus - small cardiac veins - anterior cardiac vein - Walls of right atrium - Superior wall → opening of SVC (gets blood from upper part of the body) - Inferior wall → right atrioventricular orifice Anterior wall → opening of small cardiac veins - Posterior wall → IVC + coronary sinus (with the coronary valve) - Medial wall → interatrial septum and fossa ovalis - Lateral wall → crista terminalis **3rd ventricle** - Superior -- corpus callosum - Inferior -- hypothalamus - Anterior -- anterior commissure + Lamina terminalis + Columns of fornix - Posterior -- habenular commissure - Lateral -- thalamus **Bile flow** Bile is produced in the liver, stored in the gallbladder, and flows through the bile ducts into the duodenum. **Rectus Sheath, borders, and what\'s made of** - Encloses the rectus abdominis muscles, located in the anterior abdominal wall. - A fibrous sheath formed by the aponeuroses of the abdominal muscles. **Semilunar line and arcuate line, location** - A curved line on either side of the rectus abdominis muscle where the aponeurosis of the oblique muscles ends. - **Location**: Lateral aspect of the rectus sheath in the anterior abdominal wall. **Vertebral artery, origin** - Right vertebral artery arises from the right subclavian artery (from brachiocephalic trunk) - Left vertebral artery arise from the left subclavian (from arch of aorta) they both ascend through the transverse foramen at the level of C6 and enter the skull and terminates as the basilar artery - Anterior spinal artery - Posterior spinal artery - Meningeal branch - Basilar artery - Posterior inferior cerebellar artery **Phrenic nerve** - A nerve that originates in the cervical plexus (C3-C5). It provides motor innervation to the diaphragm, which is essential for breathing. - **Location**: Runs from the neck down between the heart and lungs to the diaphragm. **Basilar artery** - Formed by the union of the two vertebral arteries, supplies blood to the brainstem and cerebellum. - **Location**: Runs along the anterior surface of the brainstem. **Lesser sac** - A cavity within the abdomen that is part of the peritoneal cavity. - Location: Posterior to the stomach and lesser omentum. - Is subdivision of the peritoneal cavity and is separated by folds of peritoneum. Greater sac forms the greater part of this cavity and lesser sac represent the primary right cavity of the celoma. It communicates with each other via the epiploic foramen and contain nothing. **Larynx** - It is a musculoligamentous structure with cartilaginous framework that caps the lower respiratory tract - Arterial supply: superior laryngeal artery (external carotid artery) and inferior thyroid artery (thyrocervical trunk) - Innervation: recurrent laryngeal - Muscles of the larynx: - Posterior cricoarytenoid (abduct, opens) - Lateral cricoarytenoid (adduct close) - Transverse arytenoid (adduct close) - Oblique arytenoid (adduct close) - Cricoarytenoid (only one that is supplied by the superior laryngeal external branch) - Thyroarytenoid - Thyroepiglottic - Aryepiglottic - Vocalis **Dorsal muscles of the foot** - Extensor digitorum brevis - **Action**: Extends the proximal phalanges of the 2nd, 3rd, and 4th toes at the metatarsophalangeal joints. - **Insertion**: Extensor expansion of the middle phalanges of toes 2 to 4. - **Origin**: Calcaneus (superolateral surface), interosseous talocalcaneal ligament, and inferior extensor retinaculum. - Extensor Hallucis brevis - **Action**: Extends the proximal phalanx of the great toe at the metatarsophalangeal joint. - **Insertion**: Base of the proximal phalanx of the great toe (hallux). - **Origin**: Calcaneus (superolateral surface) and inferior extensor retinaculum. - Innervated by deep fibular nerve, branch of common fibular nerve, L5,L5,S1. - In terms of cutaneous innervation: - Superficial fibular nerve, Deep fibular nerve, Saphenous nerve & Sural Nerve. - The blood supply is given by the dorsalis pedis artery, arcuate artery, lateral tarsal artery **Otic Ganglion** - The **Otic Ganglion** is a small parasympathetic ganglion located in the infratemporal fossa, just below the foramen ovale, medial to the mandibular nerve (V3). It is associated with the glossopharyngeal nerve (cranial nerve IX) and is primarily involved in providing parasympathetic innervation to the **parotid gland**, which stimulates saliva secretion. - Location: Infratemporal fossa, near the mandibular nerve (V3) and below the foramen ovale. - Function: Relays parasympathetic fibers to the parotid gland to promote saliva secretion. - Pathway: Preganglionic fibers from the glossopharyngeal nerve travel via the lesser petrosal nerve to the otic ganglion, where they synapse. Postganglionic fibers then travel with the auriculotemporal nerve to reach the parotid gland. - Clinical Relevance: Important in conditions like Frey\'s syndrome (gustatory sweating) and in surgical procedures involving the infratemporal fossa. **Cervical plexus** - The cervical plexus is formed by the ventral rami of cervical nerves C1-C4 and is located in the posterior triangle of neck. - Muscular branches: - Phrenic nerve (C3, C4 and C5 keeps the diaphragm alive) - Ansa cervicalis (sternohyoid, sternothyroid and omohyoid) - Cutaneous branches: - Lesser occipital nerve (C2 - C3) - Great auricular nerve (C2 - C3) - Transverse cervical nerve (C2 - C3) - Supraclavicular nerve (C3 - C4) **Superior vena cava** - Formation: The SVC is formed by the union of the right and left brachiocephalic veins, which are formed by the convergence of the subclavian and internal jugular veins on each side. - Location: The SVC is located in the upper chest, within the right side of the mediastinum. It descends vertically behind the first right costal cartilage and ends at the upper part of the right atrium of the heart at the level of the third right costal cartilage. - Length: Approximately 7 cm (2.75 inches) long. **Radial Nerve** - Innervates the following muscles: - Brachioradialis + Supinator + Anconeus + Lateral + Medial triceps brachii + All extensor muscles on the forearm - If it's harmed, it causes: - Global paralysis of the muscles of posterior compartment, resulting in wrist drop. Reduction of sensation in the cutaneous distribution by the posterior aspect of the hand also will cause paralysis of muscles in the posterior compartment of forearm. Patient will not be able to extend fingers **Lumbar plexus** - Formed by ventral rami of spinal lumbar nerve 1 to 4 also the 12 thoracic nerve (subcostal) gives a branch to the lumbar plexus. Terminal branches are the Obturator nerve and Femoral nerve - Iliohypogastric nerve: - Origin: L1 - Motor: Internal Oblique, Transversus Abdominis. - Sensory: Posterior Lateral Gluteal skin and skin of pubic region. - Ilioinguinal nerve: - Origin: L1 - Motor: Internal Oblique, transversus abdominis. - Sensory: Skin of upper medial thigh, skin of root of penis and anterior scrotum and mons pubis and labia majora. - Genitofemoral nerve: - Origin: L1-L2 - Motor: Genital Branch Cremaster muscle - Sensory: - Genital Branch Skin of anterior scrotum or skin of mons pubis and labia majora - Femoral Branch skin of upper superior thigh. - Lateral Femoral Cutaneous Nerve: - Origin: L2-L3 - Motor: - Sensory: Skin of the anterior and lateral thigh to the knee. - Obturator Nerve: - Origin: L2-L4 - Motor: - Anterior Division: gracilis + adductor brevis and longus - Posterior Division: Pectineus + adductor magnus + obturator internus. - Sensory: - Anterior Division: Skin on medial aspect of the thigh. - Posterior Division: Auricular Branch to knee joint and to hip joint. - Femoral Nerve: - Origin: L2-L4 - Motor: Iliacus, Pectineus, Muscles of anterior compartment of thigh. - Sensory: Skin on anterior thigh and medial surface of leg (saphenous v) **Aorta** - Arch of Aorta branches: It\'s a continuation of the ascending aorta which becomes the arch of aorta and continues as the descending aorta. Branches of the arch of aorta are brachiocephalic trunk and left common carotid and left subclavian artery. - Arch of Aorta is located in the 2^nd^ rib to the T4 vertebra - Now, the aorta, as it is, it's the largest artery in the human body. It has the ascending aorta, aortic arch, descending aorta and abdominal aorta **Corticospinal tract** - It is part of the pyramidal pathway. It is divided into Lateral corticospinal tract and Anterior corticospinal tract. It\'s a descending pathway and consist of two neuron, upper and lower motor neurons. Both innervate skeletal muscles. - 1st order neuron → Precentral gyrus (Primary motor cortex), anterior corticospinal tract and lateral corticospinal tract goes via upper motor neuron to - 2nd order neuron → spinal cord - Lateral corticospinal: to the interneurons of anterior horn, controls the muscles of the limb + proximal joint (IS A CROSSED PATHWAY) - Anterior corticospinal: to dorsal column , controls trunk muscles and proximal joint (UNCROSSED) **Sacral Plexus** - Ventral rami of L4 - S4 lies on anterior surface of piriformis muscle in the gluteal region The sacral nerves pass through the anterior sacral foramina - Terminal branches are the pudendal nerve - Branches: - Sciatic Nerve: - Origin: - Tibial Part: L4-S3 - Common Fibular Part: L4-S2 - Motor: - Tibial Part: All muscles of posterior compartment of thigh and leg. All muscles in sole of foot. - Common Fibular Part: Short head of biceps, all muscles in anterior and lateral compartment of leg, extensor digitorum brevis. - Sensory: - Tibial Part: Skin of posteriorlateral and lateral surface of foot and sole of foot. - Common Fibular Part: skin of anteriorlateral surface of leg and dorsal surface of foot. - Pudendal Nerve: - Origin: S2-S4 - Motor: Skeletal muscles in perineum, external urethral and anal sphincter and levator ani. - Sensory: Most of perineum penis and clitoris. - Superior Gluteal Nerve: - Origin: L4-S1 - Motor: Gluteus medius, minimus & tensor fascia latae. - Sensory: - - Inferior Gluteal Nerve: - Origin: L5-S2 - Motor: Gluteus Maximus - Sensory: - Nerve to Obturator Internus and Gemellus Superior: - Origin: L5-S2 - Motor: Obturator internus and superior gemellus - Sensory: - Nerve to Quadratus femoris and Gemellus inferior: - Origin: L2-S1 - Motor: Quadratus femoris and inferior gemellus - Sensory: - Posterior femoral cutaneous nerve: - Origin: S1-S3 - Motor: - Sensory: Skin on the posterior aspect of thigh, skin over gluteal fold. - Nerve to piriformis: - Origin: S1-S2 - Motor: Piriformis muscle - Sensory: - Pelvis Splanchnic nerves: - Origin: S2-S3 - Motor: - Visceral motor to pelvic part of prevertebral plexus. - Stimulate erection modlaye mobility in gastrointestinal system distal to left flexure - Inhibitor to the internal urethral sphincter - Sensory: - Visceral efferents from pelvic viscera and distal part of colon. - Pain from cervix, from bladder and proximal urethra. **Femoral canal** - Femoral canal/ ring (Lamp) - Anterior - inguinal ligament - Posterior - pecten pubis - Lateral - femoral vein - Medial - lacunar ligament - Femoral triangle (msl) - - - - - - - - **Carpal tunnel** - Roof -- flexor retinaculum - Floor -- carpal arch (lateral: scaphoid and trapezium and medially hook of hamate and pisiform) - Flexor digitorum superficialis tendon - Flexor digitorum profundus tendon - Flexor pollicis longus tendon - Median nerve **Innervation of foot (plantar)** - Tibial nerve (by Lateral plantar nerve and Medial plantar nerve) - Sural nerve - Saphenous nerve **Great Saphenous vein** - Originates: from the medial side of dorsal venous arch, ascends up to the medial side of the - leg, knee and thigh. Inferior to the inguinal ligament it drain into femoral vein - terminates: from Medial marginal vein → to Femoral vein - Tributaries: - External pudendal veins - Superficial circumflex iliac vein - Superficial epigastric vein - Superficial dorsal veins of penis/ clitoris - Accessory saphenous vein - Anterior scrotal veins - Anterior labial veins **Medial malleolar canal** - Contents (it also goes through flexor retinaculum of leg): - TENDON OF: Tibialis posterior - Flexor digitorum longus - Flexor hallucis longus - Posterior tibial vessels - Tibial nerve **Brachial plexus** - The brachial plexus arises from the ventral Ramus/branch of C5 - T1, it divides into roots, trunks (superior, middle and inferior) , division (anterior and posterior), cords (lateral, medial and posterior) and branches (musculocutaneous, ulnar, median axillary and radial nerve) **Sensory speech area (WERNICKE'S AREA)** - The sensory center of speech is the Wernicke\'s area, it is located in the superior temporal lobe in brodmann area 22, (angular gyrus and supramarginal gyrus) - This area is very important for language DEVELOPMENT, it is responsible for comprehension of speech meaning understanding of written and spoken language. **Motor speech area (BROCA'S AREA):** - The motor center of speech is the Broca\'s area, it is located in the inferior frontal gyrus in the brodmann\'s area 44 and 45 and divides into pars opercularis and pars triangularis - This area is very important for language PRODUCTION, as it activates the mouth and tongue region of the motor cortex for the articulation of speech production (dvs muscles). - Lesion of wernickes → fluent nonsens - Lesion of broca\'s → halting speech (slow speech) **Diencephalon:** - Also called Thalmencephalon, it is a division from the procephalon and it is made of: - Thalamus(motor and sensory signal) - Metathalamus (geniculate bodies, for visual and auditory pathway) - Epithalamus (pineal body for manufacture of melatonin and habenula for feeding behavior) - Hypothalamus (endocrine system) - Subthalamus **Thoracic duct:** - The thoracic duct arises from the cisterna chyli at the level of T12 -- L 1 and ascends through the aortic hiatus. - It lies on the right side until the level T4 (sternal angle) where it crosses to the left to drain into the left venous angle (between the subclavian and internal jugular veins) - It drains lymph from ¾ of the body. Duodenum - The **duodenum** is the first part of the small intestine, playing a crucial role in digestion by mixing partially digested food (chyme) from the stomach with bile and pancreatic juices. It is about 25-30 cm long. - Arterial supply: - **Proximal Half**: Supplied by the **superior pancreaticoduodenal artery** (a branch of the gastroduodenal artery from the celiac trunk). - **Distal Half**: Supplied by the **inferior pancreaticoduodenal artery** (a branch of the superior mesenteric artery). - Innervation: - **Parasympathetic Innervation**: Provided by the **vagus nerve**, which stimulates digestive activity. - **Sympathetic Innervation**: Provided by the **greater splanchnic nerves** via the **celiac plexus**, which inhibits digestive activity and reduces blood flow during stress. - Venous Drainage: - Duodenal veins drain into the **superior mesenteric vein**, which then contributes to the portal venous system. - **Parts of the Duodenum**: - **Superior (First) Part**: Begins at the stomach's pylorus; prone to ulcers. - **Descending (Second) Part**: Contains the **major duodenal papilla**, where the bile duct and pancreatic duct open. - **Horizontal (Third) Part**: Passes horizontally in front of the aorta and inferior vena cava. - **Ascending (Fourth) Part**: Ends at the **duodenojejunal flexure**, supported by the **ligament of Treitz**. **Pathway for pain and temperature** - The pathway for pain and temperature is the lateral spinothalamic tract - 1st order neuron → spinal ganglion - 2nd order neuron → posterior horn of spinal cord (also decussate at the anterior commissure but rather than ascending directly to VPL nucleus it goes through lateral funiculus and reticular formation) - 3rd order neuron → ventral posterolateral nucleus **Pathway for light touch**: - The pathway is anterior spinothalamic tract: - 1st order neuron → spinal root ganglion - 2nd order neuron → posterior horn of the spinal cord (decussate in the anterior commissure and ascends in anterior funiculus) - 3rd order neuron → ventral nucleus of thalamus to terminate in the postcentral gyrus **External carotid** - The **external carotid artery (ECA)** is one of the two main branches of the common carotid artery, the other being the internal carotid artery (ICA). The ECA primarily supplies blood to the face, scalp, neck, and external structures of the head. - **Origin**: The external carotid artery arises from the **common carotid artery** at the level of the upper border of the **thyroid cartilage** (around the level of the C4 vertebra). - **Course**: It ascends through the neck, passing through the **parotid gland** and ending in the substance of the parotid gland behind the neck of the mandible, where it divides into its terminal branches. - **Location**: The ECA runs superficially to the internal carotid artery and is found in the anterior triangle of the neck. It travels alongside several nerves and is covered by the sternocleidomastoid muscle at certain points. - Anterior Branches: Superior Thyroid Artery, Lingual Artery, Facial Artery. - Posterior Branches: Occipital Artery, Posterior Auricular Artery. - Medial Branch: Ascending Pharyngeal Artery. - Terminal Branches: Maxillary Artery, Superficial Temporal Artery. **Medulla oblongata** - The **medulla oblongata** is the lower part of the brainstem, located just above the spinal cord and below the pons. It plays a crucial role in autonomic functions and serves as a conduit for communication between the brain and spinal cord. - **Location**: The medulla oblongata extends from the foramen magnum (where the spinal cord enters the skull) to the pons. It is situated anterior to the cerebellum and posterior to the spinal cord. - **Structure**: It is an elongated, cylindrical structure that is continuous with the spinal cord. Its surface has a characteristic \"pyramidal\" shape due to the presence of the pyramidal tracts, which are important for motor control. - **Cranial Nerves**: - Glossopharyngeal Nerve (CN IX) - Vagus Nerve (CN X) - Accessory Nerve (CN XI) - Hypoglossal Nerve (CN XII) - Pathways: - **Motor Pathways**: The medulla contains the **pyramidal tracts**, which carry motor signals from the cerebral cortex to the spinal cord. These tracts decussate (cross over) at the level of the medulla, meaning motor control is generally contralateral (opposite side) to the brain\'s control. - **Sensory Pathways**: It transmits sensory information from the body to the brain, including touch, pressure, and proprioception. **Ankle joint** - Synovial hinge joint formed by distal end of tibia and fibula and proximal end of talus) - Movements: Dorsiflexion and Plantarflexion - Ligaments: medial deltoid ligament, lateral ligament , anterior and posterior talofibular ligament and tibiofibular - Arterial supply: Anterior and posterior tibial artery and anterior and posterior fibular artery - Innervation: deep fibular/ peroneal, saphenous, sural and tibial nerves