Anatomy Theory Final

What is the frontal, sagittal and transverse sections and describe each section you see?

Frontal/coronal = divides anterior and posterior; Sagittal = divides left and right; Transverse/axial = divides superior and inferior.

Which thoracic cage joints are synovial and why?

Costovertebral joints; costotransverse joints; sternocostal joints 2–7; manubriosternal joint. They allow thoracic cage movement during breathing.

What joints and structures move during CPR?

Sternum; ribs; sternocostal joints; heart is compressed between sternum and vertebral column.

Which thoracic cage joints are primary cartilaginous?

First sternocostal joint and costochondral joints.

Which structure is most at risk in an intercostal space and why?

Intercostal neurovascular bundle, because it runs in the costal groove on the inferior border of the rib.

What are the contents of an intercostal space?

External, internal and innermost intercostal muscles; intercostal vein, artery and nerve; fascia; parietal pleura.

What are the functions of the intercostal muscles?

External intercostals elevate ribs during inspiration; internal intercostals depress ribs during forced expiration; both stabilise intercostal spaces.

Name 3 veins involved in left-to-right venous shunting.

Azygos vein; hemiazygos vein; accessory hemiazygos vein.

How do diaphragm openings reflect structure and function?

Caval opening widens during inspiration to increase venous return; oesophageal hiatus helps prevent reflux; aortic hiatus prevents aortic compression.

What passes through or behind the diaphragm?

T8 = IVC and right phrenic nerve; T10 = oesophagus and vagal trunks; T12 = aorta, thoracic duct and azygos vein.

Which organs contact the diaphragm?

Liver; stomach; spleen; kidneys; lungs; heart.

What pressure and volume changes occur with diaphragmatic movement?

Diaphragm contracts and flattens; thoracic volume increases; thoracic pressure decreases; abdominal pressure increases.

What structures and muscles are involved in breathing?

Inspiration: diaphragm contracts downward and external intercostals elevate ribs/sternum. Deep inspiration uses SCM and scalenes. Expiration: diaphragm/external intercostals relax. Forced expiration uses internal intercostals and abdominal muscles.

What are the boundaries of the inferior thoracic aperture?

Posterior = T12 vertebra; posterolateral = ribs 11 and 12; anterolateral = costal margin; anterior = xiphisternal joint.

What structures pass through the inferior thoracic aperture?

Caval opening T8: IVC and right phrenic nerve; oesophageal hiatus T10: oesophagus, vagal trunks, oesophageal vessels; aortic hiatus T12: aorta, thoracic duct, azygos vein; sympathetic trunks pass posteriorly; splanchnic nerves pierce crura.

What are the boundaries of the superior thoracic aperture?

Posterior = T1 vertebra; lateral = first ribs/costal cartilages; anterior = superior border of manubrium.

What structures pass through the superior thoracic aperture?

Trachea; oesophagus; lung apices and cervical pleura; brachiocephalic trunk; left common carotid; left subclavian; brachiocephalic veins; vagus nerves; phrenic nerves; sympathetic trunks.

What are the major structures in the mediastinal compartments?

Superior = trachea, oesophagus, great vessels; middle = heart and pericardium; posterior = oesophagus, thoracic aorta, azygos vein. Anterior = thymus

Trace the pathway of air through the bronchial tree.

Nose/mouth → pharynx → larynx → trachea → main bronchi → lobar bronchi → segmental bronchi → subsegmental bronchi → terminal bronchioles → respiratory bronchioles → alveolar ducts → alveolar sacs/alveoli.

Describe the lymphatic drainage of the lungs.

Bronchopulmonary nodes → tracheobronchial nodes → bronchomediastinal trunks → venous angles.

Difference between pulmonary and bronchial circulation?

Pulmonary circulation carries deoxygenated blood for gas exchange; bronchial circulation supplies oxygenated blood to lung tissue.

What are the parts of the parietal pleura?

Costal pleura; diaphragmatic pleura; mediastinal pleura; cervical pleura.

What vessels run with the phrenic nerves?

Pericardiacophrenic arteries and veins.

Describe the steps in coronary angioplasty.

Catheter inserted into coronary artery, enters through either radial or femoral artery; balloon inflated to widen stenosis; stent inserted to maintain patency.

Why is the left ventricle thicker than the right ventricle?

Left ventricle pumps to systemic circulation, so it needs to generate higher pressure.

Where is blood most likely to clot in atrial fibrillation?

Left atrial appendage.

Describe the pathway of blood through the heart.

Body → SVC/IVC → right atrium → tricuspid valve → right ventricle → pulmonary valve → pulmonary trunk/arteries → lungs → pulmonary veins → left atrium → mitral valve → left ventricle → aortic valve → aorta → body.

Functions of the 4 heart valves?

Tricuspid prevents backflow into right atrium; pulmonary prevents backflow into right ventricle; mitral prevents backflow into left atrium; aortic prevents backflow into left ventricle.

Describe the cardiac electrical conduction pathway.

SA node fires → impulse spreads through atria → atria contract → AV node delay → Bundle of His → right/left bundle branches → Purkinje fibres → ventricles contract together.

Why does the heart need extrinsic nervous control?

Sympathetic stimulation increases heart rate and contractility; parasympathetic stimulation decreases heart rate.

Describe the relationships of the aorta.

Ascending aorta is anterior to pulmonary trunk/RV/SVC; aortic arch is posterior to trachea; descending thoracic aorta is posterior to oesophagus and near thoracic duct/azygos vein.

How does the azygos system connect the IVC and SVC?

Azygos vein ascends on right and drains into SVC; hemiazygos/accessory hemiazygos drain left thorax into azygos; provides collateral venous pathway if IVC/SVC obstructed.

Where are ascending lumbar veins found?

Posterior abdominal wall beside lumbar vertebrae; connect common iliac veins with azygos system; deep to psoas major.

Name 3 veins crossing the midline for left-to-right shunting.

Hemiazygos vein; accessory hemiazygos vein; posterior intercostal veins.

Difference between right and left recurrent laryngeal nerves?

Right recurrent laryngeal nerve loops under right subclavian artery; left loops under aortic arch near ligamentum arteriosum; left has longer intrathoracic course and is more vulnerable to compression.

Differences between right and left phrenic nerve course?

Both pass anterior to lung roots; right passes beside SVC; left crosses aortic arch.

Why does diaphragm irritation cause shoulder pain?

Phrenic nerve C3–C5 shares spinal segments with shoulder dermatomes.

Where is the cardiac plexus located?

Near tracheal bifurcation and aortic arch.

Why is ischemic heart pain referred to left chest and arm?

Cardiac visceral afferents enter T1–T5 spinal levels, which also supply chest and arm dermatomes.

Name 3 venous drainage pathways of the oesophagus.

Azygos vein; hemiazygos vein; left gastric vein to portal system.

Describe the arterial supply to the oesophagus.

Cervical = inferior thyroid arteries; thoracic = thoracic aorta and bronchial arteries; abdominal = left gastric and inferior phrenic arteries.

Describe thoracic oesophagus relationships.

Anterior = trachea and left atrium; posterior = vertebral column; left = thoracic aorta; right = azygos vein; thoracic duct posterior; passes through diaphragm at T10.

Describe the course of the thoracic duct.

Cisterna chyli L1–L2 → aortic hiatus T12 → ascends between thoracic aorta and azygos vein → crosses right to left at T4–T6 → drains into left venous angle.

What is the clinical significance of the venous angles?

Drainage sites of thoracic duct and right lymphatic duct.

Describe the relationship of thoracic duct to azygos vein and oesophagus.

Between azygos vein and thoracic aorta; posterior to oesophagus; crosses behind oesophagus.

Why does breast cancer cause skin dimpling?

Cancer invades Cooper ligaments, causing fibrosis and retraction.

Name 3 arterial supplies to the breast.

Internal thoracic artery; lateral thoracic artery; posterior intercostal arteries.

Describe 2 lymphatic drainage pathways of the breast to the right venous angle.

Breast → axillary nodes → right lymphatic duct → right venous angle; breast → supraclavicular nodes → right lymphatic duct → right venous angle.

What organs are in the abdominal quadrants?

RUQ = liver, gallbladder, right kidney, duodenum; RLQ = appendix, cecum, right ovary, right ureter; LUQ = stomach, spleen, left kidney, pancreas; LLQ = sigmoid colon, left ovary, left ureter.

What structures are found at the transpyloric plane?

Pylorus; SMA origin; kidney hila; duodenojejunal flexure.

Describe the layers of the anterior abdominal wall superficial to deep.

Skin → Camper’s fascia → Scarpa’s fascia → external oblique → internal oblique → transversus abdominis → transversalis fascia → extraperitoneal fat → parietal peritoneum.

Difference between indirect and direct inguinal hernia?

Indirect passes lateral to inferior epigastric vessels through deep ring; direct passes medial through inguinal triangle.

What are the boundaries of the inguinal triangle?

Rectus abdominis; inferior epigastric vessels; inguinal ligament.

Why are males more likely to get inguinal hernias?

Larger inguinal canal due to testicular descent weakens the abdominal wall.

What is the Valsalva manoeuvre?

Forced expiration against closed glottis; increases intra-abdominal pressure; makes hernias more prominent; can reduce venous return by compressing femoral vein.

Define femoral sheath, femoral canal and femoral ring.

Femoral sheath surrounds femoral vessels; femoral canal is medial compartment; femoral ring is superior opening of femoral canal.

What passes through the retroinguinal space?

Lateral compartment = iliopsoas and femoral nerve; medial compartment = femoral artery, femoral vein, femoral canal, lymphatics, femoral branch of genitofemoral nerve.

Where do femoral hernias occur?

Through femoral canal via femoral ring below the inguinal ligament.

Describe foregut, midgut and hindgut supply, drainage and innervation.

Foregut = coeliac trunk, portal vein, greater splanchnic T5–T9, vagus, example stomach; midgut = SMA, SMV to portal vein, lesser splanchnic T10–T11, vagus, example jejunum; hindgut = IMA, IMV to splenic vein to portal vein, lumbar splanchnic L1–L2, pelvic splanchnic S2–S4, example descending colon.

Describe the pathway of food through the GIT.

Mouth → pharynx → oesophagus → stomach → duodenum → jejunum → ileum → cecum → ascending colon → transverse colon → descending colon → sigmoid colon → rectum → anus.

Describe the arterial supply of the large intestine.

SMA supplies proximal colon; IMA supplies distal colon.

Which organs are retroperitoneal?

Kidneys; pancreas except tail; duodenum parts 2–4; ascending colon; descending colon.

Difference between intraperitoneal and retroperitoneal organs?

Intraperitoneal organs are suspended by mesentery and mobile; retroperitoneal organs are fixed posteriorly.

Why is parietal peritoneum pain well localised but visceral peritoneum pain poorly localised?

Parietal peritoneum has somatic nerve supply causing sharp localised pain; visceral peritoneum has autonomic visceral afferents causing dull poorly localised pain.

What nerves carry foregut, midgut and hindgut visceral pain?

Foregut = greater splanchnic T5–T9; midgut = lesser splanchnic T10–T11; hindgut = lumbar splanchnic L1–L2.

Describe the arterial supply of the stomach.

Left gastric artery; right gastric artery; right gastro-omental artery; left gastro-omental artery;

Describe venous drainage of the stomach.

Left/right gastric veins → portal vein; left gastro-omental veins → splenic vein; right gastro-omental vein → SMV.

Describe the normal supine position of the stomach.

LUQ and epigastrium; anterior relations = liver, diaphragm, abdominal wall; posterior relations = pancreas, spleen, left kidney, left suprarenal gland, transverse colon.

Why is gastroduodenal artery bleeding from a peptic ulcer dangerous?

Posterior duodenal ulcers can erode the gastroduodenal artery, causing massive haemorrhage.

Name the 4 parts of the duodenum and key anatomy.

1st part = related to gastroduodenal artery; 2nd = receives bile and pancreatic ducts; 3rd = crossed anteriorly by SMA/SMV; 4th = duodenojejunal flexure and ligament of Treitz.

Describe appendix positions and symptoms.

Retrocaecal = flank/back pain and positive psoas sign; pelvic = suprapubic pain, urinary symptoms and positive obturator sign; pre/post-ileal = central pain; early appendicitis = umbilical visceral pain; late appendicitis = RLQ somatic pain.

Structural differences between duodenum, jejunum and ileum?

Duodenum has Brunner glands; jejunum has thick walls, long vasa recta and prominent plicae circulares; ileum has Peyer patches, short vasa recta and more arcades.

Describe 3 porto-systemic anastomoses and their consequences.

Oesophagus: left gastric ↔ azygos veins → oesophageal varices; umbilicus: paraumbilical ↔ superficial epigastric veins → caput medusae; rectum: superior rectal ↔ middle/inferior rectal veins → anorectal varices.

Describe the dual blood supply of the liver.

Portal vein supplies nutrient-rich blood; proper hepatic artery supplies oxygenated blood; blood flows through sinusoids → central veins → hepatic veins → IVC.

Symptoms of gallstones in gallbladder or cystic duct?

Biliary colic; RUQ pain; pain after fatty meals; nausea/vomiting; right shoulder referred pain; possible cholecystitis.

Symptoms of gallstone blockage at hepatopancreatic ampulla?

Obstructive jaundice; dark urine; pale stools; acute pancreatitis; severe epigastric pain radiating to back.

Describe bile flow through the biliary tree.

Hepatocytes → bile canaliculi → interlobular ducts → right/left hepatic ducts → common hepatic duct → cystic duct/gallbladder OR common bile duct → hepatopancreatic ampulla → major duodenal papilla → duodenum.

Surface anatomy of the gallbladder?

Right midclavicular line + right costal margin; tip of right 9th costal cartilage; Murphy’s point.

Describe blood flow through the glomerulus from aorta to IVC.

Aorta → renal artery → segmental artery → interlobar artery → arcuate artery → cortical radiate artery → afferent arteriole → glomerulus → efferent arteriole → peritubular capillaries/vasa recta → cortical radiate vein → arcuate vein → interlobar vein → renal vein → IVC.

Name the 3 ureter constriction points.

Ureteropelvic junction; pelvic brim crossing; vesicoureteric junction.

What is the muscular bed of the kidney?

Psoas major; quadratus lumborum; transversus abdominis; diaphragm.

Describe arterial supply and venous drainage of adrenal glands.

Superior suprarenal arteries from inferior phrenic arteries; middle suprarenal arteries from abdominal aorta; inferior suprarenal arteries from renal arteries; right adrenal vein drains directly to IVC; left adrenal vein drains to left renal vein then IVC.

Describe adrenal gland innervation.

Sympathetic fibres T5–T11 via thoracic splanchnic nerves; preganglionic fibres synapse directly on chromaffin cells causing adrenaline/noradrenaline release.

Why is splenic vein blood different from SMV blood?

Splenic vein contains RBC breakdown products, immune cells and recycled iron; SMV contains nutrient-rich blood from intestines.

Surface anatomy of spleen?

LUQ between ribs 9–11 along midaxillary line.

Describe microcirculation of the spleen.

Splenic artery → trabecular arteries → central arterioles → penicillar arterioles → red pulp cords → splenic sinusoids → veins; advantage = filters abnormal RBCs/pathogens; disadvantage = blood cell sequestration and splenomegaly.

Describe arterial supply route to the stomach greater curvature.

LV → ascending aorta → arch → thoracic aorta → abdominal aorta → coeliac trunk → splenic artery → left gastro-omental artery → stomach OR coeliac trunk → common hepatic artery → gastroduodenal artery → right gastro-omental artery → stomach.

Describe arterial supply route to the appendix.

LV → aorta → SMA → ileocolic artery → appendicular artery → appendix.

Describe arterial supply route to sigmoid colon.

LV → aorta → IMA → sigmoid arteries → sigmoid colon.

Describe arterial supply route to psoas/quadratus lumborum.

LV → aorta → lumbar arteries → muscles.

Describe arterial supply route to kidney.

LV → aorta → renal artery → segmental aa → interlobar aa → arcuate aa → cortical radiate aa → kidney.

Describe arterial supply route to gonads.

LV → aorta → testicular/ovarian artery → gonad.

Describe 3 arterial routes to adrenal gland.

Aorta → inferior phrenic artery → superior suprarenal artery; aorta → middle suprarenal artery; aorta → renal artery → inferior suprarenal artery.

Name tributaries of the IVC from inferior to superior.

Common iliac veins; lumbar veins; gonadal veins; renal veins; suprarenal veins; hepatic veins; inferior phrenic veins.

Describe 2 left vs right IVC drainage differences.

Right gonadal vein drains directly to IVC while left drains to left renal vein; right suprarenal vein drains directly to IVC while left drains to left renal vein.

Describe lymphatic drainage of foregut, midgut and hindgut.

Foregut stomach → gastric nodes → coeliac nodes; midgut appendix → ileocolic nodes → superior mesenteric nodes; hindgut sigmoid colon → sigmoid nodes → inferior mesenteric nodes.

Why can stomach cancer cause a left neck lump?

Cancer cells can spread via thoracic duct to the left supraclavicular node, also called Virchow node.

What organs are supplied by the foregut?

Oesophagus; stomach; proximal duodenum; liver; gallbladder; pancreas; spleen.

What organs are supplied by the midgut?

Distal duodenum; jejunum; ileum; cecum; appendix; ascending colon; proximal two-thirds of transverse colon.

What organs are supplied by the hindgut?

Distal one-third of transverse colon; descending colon; sigmoid colon; rectum.