MICN201 Anatomy [All] labs summary notes PDF

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Key notes from all the anatomy labs ...

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MSK ❖ Linea aspera - rough line on posterior aspect of femoral shaft - divides into pectineal line + gluteal tuberosity ➢ Short head of biceps femoris arises from here ❖ Medial epicondyle of femur - muscle attachments = Say Grace before Ten (sartorius, gracilis, semitendinosus) = pes anserinus (goose foot) Calcaneonavicular ligament = spring (A → D) maintains medial arch. Calcaneocuboid ligament = long plantar (A → C) maintains lateral arch along with short plantar ligament - Transverse arch maintained by fibularis longus tendon ➔ Calcaneus - sustentaculum tali (medial side prominent shelf of bone)

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Tarsal tunnel contents = Tom, Dick And Very Naughty Harry ● Tibialis anterior, flexor Digitorum longus, posterior tibial Artery, tibial Vein, tibial Nerve, flexor Hallucis longus tendon Hip joint muscles ● Flexion: iliacus, psoas major, sartorius, rectus femoris, tensor fascia latae ● Extension: gluteus maximus, biceps femoris (long head), semimembranosus, semitendinosus, adductor magnus (ischial part) ● Abduction: gluteus medius and minimus ● Adduction: adductor longus/brevis/magnus ● Medial rotation: gluteus medius and minimus (anterior fibres), tensor fascia latae ● Lateral rotation: sartorius, gluteus maximus, piriformis, obturator internus and externus, superior/inferior gemelli, quadratus femoris Knee joint muscles ● Extension: rectus femoris, vastus medialis/lateralis/intermedius (quads) ● Flexion: biceps femoris, semimembranosus, semitendinosus (hamstrings), gastrocnemius, sartorius, gracilis, popliteus ● Medial rotation: semimembranosus, semitendinosus, popliteus, sartorius, gracilis ● Lateral rotation: biceps femoris Extrinsic muscles of ankle/foot ● Plantar flexion: gastrocnemius, soleus, tibialis posterior, flexor digitorum/hallucis longus; fibularis longus and brevis ● Dorsiflexion: tibialis anterior, extensor hallucis/digitorum longus, fibularis tertius ● Inversion: tibialis anterior and posterior, extensor hallucis longus ● Eversion: fibularis longus/brevis/tertius

Nerves and BVs of: Anterior and medial aspects of thigh

Femoral nerve, saphenous nerve (cutaneous supply to medial side of leg and foot), obturator nerve External iliac, femoral, deep femoral (profunda femoris) - artery and vein Lateral and medial circumflex artery Obturator artery and vein Great saphenous vein

Gluteal region

Sciatic nerve (with tibial and common fibular divisions) Superior and inferior gluteal nerve Superior and inferior gluteal artery and vein

Popliteal region

Tibial nerve, common fibular nerve Popliteal artery and vein Small saphenous vein

Leg and foot

Tibial nerve -> medial and lateral plantar nerve Superficial and deep fibular nerve Posterior tibial, fibular and anterior tibial - artery and vein Dorsalis pedis artery Dorsal venous network of foot

Axilla and arm

Axillary artery and vein Anterior and posterior circumflex humeral artery Brachial plexus: musculocutaneous, axillary, radial, median, ulnar Brachial, deep brachial (profunda brachii) - artery and vein Cephalic vein

Cubital region

Median, ulnar, radial nerves Brachial, ulnar, radial arteries

Forearm

Median nerve + anterior interosseous (deep branch of median) Brachial, ulnar, radial arteries Ulnar nerve + dorsal branch of ulnar Radial nerve + superior branch + deep branch -> deep continues as posterior interosseous nerve Common interosseous artery -> anterior + posterior interosseous artery Cephalic and basilic vein

Hand

Median nerve + recurrent branch of median Ulnar nerve + dorsal and deep branch of ulnar Radial nerve + superficial branch of radial Digital nerves Superficial and deep palmar arch Dorsal carpal arch Digital arteries Dorsal venous network of hand

Muscles attaching axial skeleton to shoulder girdle - movement of scapula ● Trapezius - elevation (upper part), depression (lower part), retraction (middle part), lateral rotation ● Rhomboids (major, minor) - elevation, retraction, medial rotation ● Levator scapulae - elevation, medial rotation ● Serratus anterior - protraction, lateral rotation (lower part) ● Pectoralis minor - depression, medial rotation Muscles attaching axial skeleton to humerus - movement of humerus at shoulder joint ● Pectoralis major - adduction (sternocostal part), flexion (clavicular part), medial rotation ● Latissimus dorsi - adduction, medial rotation Muscles attaching shoulder girdle to humerus - movement of humerus at shoulder joint ● Deltoid - abduction (acromial part), flexion (clavicular part), extension (posterior part) ● Subscapularis - medial rotation ● Supraspinatus - abduction ● Infraspinatus - lateral rotation ● Teres minor - lateral rotation ● Teres major - adduction, medial rotation Muscles of the arm - movement at Shoulder, Elbow, Radioulnar joints ● Biceps brachii - flexion short head (S), flexion (E), supination (RU) ● Coracobrachialis - flexion (S) ● Brachialis - flexion (E) ● Triceps brachii - extension (E) Muscles of anterior compartment of forearm - movement at (__) joints Superficial group: ● Pronator teres - pronation (RU), flexion (E) ● Flexor carpi radialis - flexion (W), abduction (W) ● Palmaris longus - flexion (W) ● Flexor carpi ulnaris - flexion (W), adduction (W) Intermediate group: ● Supinator - supination (RU) ● Flexor digitorum superficialis - flexion (W, MP, PIP) Deep group: ● Flexor digitorum profundus - flexion (W, all joints of fingers) ● Flexor pollicis longus - flexion (W, all joints of thumb) ● Pronator quadratus - pronation (RU) Muscles of posterior compartment of forearm - movement at (__) joints ● Brachioradialis - flexion (E) ● Extensor carpi radialis longus/brevis - extension (W), abduction (W) ● Extensor digitorum - extension (W, all joints of fingers) ● Extensor indicis - extension (W, all joints of index) ● Extensor digiti minimi - extension (W, all joints of little finger) ● Extensor carpi ulnaris - extension (W), adduction (W) ● Extensor pollicis longus - extension (W, all joints of thumb) ● Extensor pollicis brevis - extension (CM, MP of thumb) ● Abductor pollicis longus - abduction (CM of thumb)

Intrinsic muscles of hand - thenar eminence, hypothenar eminence, adductor pollicis, palmar and dorsal interossei, lumbricals Sympathetic nervous system ● Sympathetic chain/trunk (right and left) ● Paravertebral ganglia (ganglia of sympathetic chain) ● White rami communicans (NB: sympathetic cell bodies are located in spinal segments T1-12 and L1-3 and their axons enter ventral roots of spinal nerves) ○ May synapse on cell bodies in paravertebral ganglia at that level ○ May pass up or down a few segments in the sympathetic chain before synapsing on cell bodies in paravertebral ganglia at higher or lower level ○ May pass medially in nerve bundles to synapse on prevertebral (sympathetic) ganglia (e.g. thoracic splanchnic nerves) ● Grey rami communicans ○ Pass back to the mixed segmental nerve Musculocutaneous [3 musketeers] - C5-C7 Axillary [assassinated] - C5-6 Radial [5 rats] - C5-T1 Median [5 mice] - C5-T1 Ulnar [2 unicorns] - C8-T1 Obturator (anterior divisions L2-4), femoral (posterior divisions L2-4) Sciatic nerve - tibial (anterior divisions L4-S3), common fibular (posterior divisions L4-S2)

Myotomes - segmental innervation of muscles Upper limb C5-T1 C5 C6,7,8 C5,6,7 C5,6,7,8

Abduct/Lateral rotate Adduct/Medial rotate Flex Extend

Shoulder

C5,6 C7,8

Flex Extend

Elbow

C6,7

Flex/Extend

Wrist

C7,8

Flex/Extend

Finger and thumb (long tendons)

T1

Abduct/Adduct

Finger (intrinsic muscles)

C6 C7,8

Supinate Pronate

Forearm

Lower limb L2-S2 L2,3 L4,5

Adduct/Medial rotate/Flex Abduct/Lateral rotate/Extend

Hip

L3,4 L5,S1

Extend Flex

Knee

L4,5 S1,2

Dorsiflex Plantarflex

Ankle

L4 L5,S1

Inversion Eversion

Foot

CVD Mitral heart sound or apex beat = L5ICS/MCL Posterior pericardial sac - serous membrane, lubrication, frictionless - Closed balloon and fist analogy - anterior -> posterior -> creates pericardial sac (visceral and parietal layer) Transverse pericardial sinus - separates arteries from veins; anteriorly is the ascending aorta and pulmonary trunk; posteriorly is the superior vena cava Oblique pericardial sinus - formed by reflection onto pulmonary veins of heart Interior of RA divided into 2 continuous spaces - internally this is separated by the crista terminalis (smooth muscular ridge) - Space posterior to crista - sinus of venae cavae (embryologically from sinus venosus) smooth thin walls, both vena cava enter here - Space anterior to crista - atrium proper (includes auricle), embryologically from primitive atrium - walls covered by ridges musculi pectinati (meshwork of fibres, blood clots can form and break off -> cardioembolic stroke) Cardiac innervation - ANS directly responsible for regulating HR, C.O., force of contraction - Branches from PSNS and SNS contribute to formation of the cardiac plexus: superficial and deep part - Parasympathetic fibres reach the heart as cardiac branches from R&L vagus nerves - Sympathetic fibres reach the cardiac plexus through cardiac nerves from the sympathetic trunk - Visceral afferents pass the cardiac plexus and return to CNS in cardiac nerves from sympathetic trunk (conduct pain sensation from heart - detected at cellular level as tissue damaging events) and in vagal cardiac branches (sense alterations in BP and blood chemistry, so cardiac reflexes) Cardiac plexus sends visceral sensory fibres through sympathetic chain at level of T1-4 so visceral sensory fibres mix with somatic sensory fibres (T1-4) - dorsal root interneurons mix inputs so that heart pain is perceived as chest and left arm pain = referred pain Visceral input from pericardial sac or diaphragm enter spinal cord following path of phrenic nerve C3-5 - felt in neck, shoulder tip, jaw Intima - simple squamous endothelial cells (inner) and a thick collagenous subendothelial connective tissue Media - thickness related to pressure carried; contains elastic laminae Adventitia - outer tensile sheath, thickest layer in veins (capacitance vessels), collagen stops over-distension, vasa vasorum supplies the vessel; nerve fibres and some adipose tissue Atherosclerosis

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Disruption of the internal elastic lamina IEL and migration of smooth muscle from the media to intima Monocyte adhesion (diapedesis), transformation to tissue macrophage and formation of foam cells - fatty streak, cells uptake lipoprotein Progression of lesion. Intimal thickening, medial atrophy, adventitial inflammation Lesion complications such as cap rupture (thrombosis) and aneurysms formation Proliferative = intimal thickening -> stenosis Degenerative = medial atrophy + adventitial inflammation -> aneurysm calcific vasculopathies -> stenosis

Virchow’s triad - of thromboembolism - Blood constituents e.g. clotting factors, dyslipidemia - Rheological factors - haemodynamic - Vessel wall factors - connective tissue fragility and endothelial cell function Cardiac silhouette during respiration - Inspiration -- elongates and thinner - Expiration - shortens and fatter - In a normal heart at inspiration, the widest part lying against the diaphragm should be less than half of the greatest thoracic diameter (measured inside the ribcage) Heart & cardiac muscle histology - Epicardium = simple, squamous epithelium (visceral layer of serous pericardium) and an underlying layer containing BVs and fat tissue - Myocardium - equivalent to tunica media of blood vessels; NB: various orientation of muscle cells -> contraction of muscle = higher cardiac output - Endocardium on inner surface of ventricle = simple squamous epithelium - Cardiac muscle: cross striations visible but not prominent, elongated centrally located nuclei, fibroblasts visible between muscle fibres (for CT support), intercalated discs. Diads - 1 T-tubule + 1 sarcoplasmic reticulum Purkinje fibres - pale cytoplasm, relatively few myofibrils in peripheral position, cytoplasm is rich in glycogen and mitochondria

RESP Paranasal air sinuses - Maxillary sinus is the first aerated (pneumatization) paranasal sinus and is present in neonates - At birth, the frontal sinus is non-aerated and contains red marrow and is the last paranasal sinus to aerate Drainage of each: - Frontal -> middle nasal meatus - Maxillary -> middle nasal meatus - Ethmoidal -> middle nasal meatus (for anterior and middle), superior nasal meatus (for posterior) - Sphenoidal -> sphenoethmoidal recess

Important anatomical structure = Waldeyer ring -> nasopharyngeal tonsils (also known as adenoids) superiorly, tubal tonsils superolaterally, palatine tonsils inferolaterally and lingual tonsils inferiorly Piriform recess - on either side of aryepiglottic fold and laryngeal inlet - If something pierces through, it will hit the inferior branch of the superior laryngeal nerve - lose sensation in quadrangular membrane, so cannot close vocal folds when something passes into larynx Laryngeal cartilages The larynx is both a valve (or sphincter) to close the LRT and an instrument to make sound - 3 large unpaired cartilages: cricoid, thyroid, epiglottis - 3 pairs of smaller cartilages: arytenoid, corniculate, cuneiform - And a fibroelastic membrane and numerous intrinsic muscles Infections can spread from pharynx to mediastinum/thorax through retropharyngeal space Advanced airway obstruction is a medical emergency and requires immediate hospital admittance of the patient - airways can be secured by piercing through the cricothyroid membrane (median cricothyroid ligament) to reach LRT (below vocal cords) Pleural effusion - remove fluid from pleural cavity by inserting a wide-bore needle into the 9th intercostal space in midaxillary line during expiration (avoids inferior border of lung, superior border of liver and the intercostal nerves and vessels) Major amounts of air, blood, serous fluids, pus or any combination of these substances in the pleural cavity are typically removed by placement of a draining chest tube - For pneumothorax - 2nd or 3rd interspace at MCL - For hemothorax - 5th interspace at midaxillary line Pneumothorax - following penetrating injury to pleural cavity, air enters the pleural cavity via punctured lung during inspiration. The chest wall and lung defects act as one-way valves so that air cannot escape from the pleural cavity during expiration. The right intrapleural pressure increases, collapsing the right lung, impeding venous return to the heart and occasionally shifting the mediastinal structures to the contralateral side. Pulmonary thromboembolism - Emergency condition in which a thrombus has been released from the great saphenous vein or one of its tributaries. This is then transported to the pulmonary circulation where it causes complete or almost complete blockage of the pulmonary artery - may block most of the blood flow through the lungs and then to the left side of the heart, causing a rapid drop in BP -> shock and death

GI Oral cavity ● Opening: oral fissure (anterior) + oropharyngeal isthmus (posterior opening demarcated by palatoglossal folds/arches) ● Regions: vestibule + oral cavity proper ● Roof: hard palate + soft palate (muscles: levator palati, tensor palati, palatoglossus, palatopharyngeus, musculus uvulae) ● Floor: muscles (geniohyoid, mylohyoid) and CT

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Tongue: intrinsic muscles (arranged in 3 planes) + extrinsic muscles (styloglossus, palatoglossus, hyoglossus, genioglossus) [Short fenulum - tongue tied - in babies: can’t suckle properly] Parotid -> vestibule opposite upper 2nd molar Submandibular -> oral cavity proper on sublingual papilla (caruncle) Sublingual -> oral cavity proper on sublingual fold Pharynx Layers of wall: mucosa, fibrous (pharyngopharyngeal fascia), muscle, fascia (buccopharyngeal fascia) Inner: Levator muscles - Palatopharyngeus (produces palatopharyngeus fold of mucous membrane) - Salpingopharyngeus (produces salpingopharyngeal fold) - Stylopharyngeus Outer: Constrictors of pharynx (S/M/I) overlap allowing continuous peristalsis; inferior constrictor muscle comprises thyropharyngeus and cricopharyngeus Pharyngeal diverticulum or pouch may occur in the pharyngeal wall where there is muscular weakness (where muscles overlap or between muscles e.g. Morgagni sinus between superior constrictor muscle and base of skull) - Symptoms of dysphagia, sensation of food sticking in throat and regurgitation - More likely to be observed on the left side than right, as the oesophagus is more to the left in this area - Surgical treatment: excision of the pouch, repair of the defect and division of the pharyngeal muscle fibres below the defect - Most common life threatening complication in generally older patients - pulmonary aspiration Narrowest part of esophagus = at the upper oesophageal sphincter ~C6 (cricopharyngeus muscle at lower part of inferior pharyngeal constrictor) ~15 cm from incisors -- important when introducing a nasogastric tube or endoscope - Other narrowings caused by: aortic arch, left main bronchus (25 cm from incisors), diaphragm (40 cm from incisors ~T10) Hiatus herniation - herniation of the gastroesophageal region of the stomach into the thoracic cavity through an opening in the diaphragm - Very common, especially in older people Small intestine - Plicae circularis (circular folds) but not in superior part of duodenum - Mesentery: suspends jejunum and ileum from posterior abdominal wall (carries blood vessels, lymphatics - Peyer’s patches, and nerve fibres) Large intestine - Taenia coli (longitudinal muscle 3 bands - forms one layer at rectum and appendix) - Epiploic appendages (droplets of fat attached to colon) - Haustra (pockets separated by plicae semilunaris) Anorectal angle created by puborectalis muscle (pubic symphysis rectum), helps fecal continence, as does the 3 transverse folds (shelves)

In performing a splenectomy, the pancreas can be potentially damaged (tail part closed to the spleen, and is also intraperitoneal compared to rest of pancreas) Biliary colic due to obstruction of bile duct causing inflammation/infection - Pain is felt in upper right abdomen - epigastrium (parietal peritoneum irritation giving localised pain), and radiates to the back in the region of the right scapula (referred pain for T7-9) Abdomen quadrants and contents for lower GIT R upper Distal part of ascending colon

L upper Distal part of transverse colon L colic (splenic) flexure Proximal part of descending colon

R lower Cecum Appendix Terminal ileum Proximal part of ascending colon

L lower Distal part of descending colon Sigmoid colon

Examination of GI system ➢ Upper GIT: X-ray, CT and MRI, endoscopy, gastroscopy, barium swallow/meal/ follow-through ➢ Lower GIT: X-ray, CT and MRI, proctoscopy, sigmoidoscopy, colonoscopy, barium enema ➢ Liver, gallbladder, pancreas: CT and MRI, ultrasonography, cholecystography (gallbladder)

Blood vessels Arteries ● Pharyngeal arteries (ascending pharyngeal artery from ECA) ● Esophageal arteries (from thoracic aorta) ● Celiac artery (from abdominal aorta at T12) ○ Left gastric artery - lesser curvature of stomach ○ Splenic artery -> left gastroepiploic artery ○ Common hepatic artery -> proper hepatic artery; gastroduodenal -> right gastric + right gastroepiploic artery ● Superior mesenteric artery (from AA at L1) ○ Jejunal and ileal artery ○ Ileocolic artery ○ Right colic artery ○ Middle colic artery ● Inferior mesenteric artery (from AA at L3) ○ Left colic artery ○ Sigmoid artery ○ Superior rectal artery Veins

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Esophageal veins drain to azygos vein and left gastric vein Splenic vein accompanies splenic artery Veins accompany branches of SMA/IMA and drain into SMV/IMV Inferior mesenteric vein usually joins with splenic vein Por...