Anatomy Review: Lower Extremity, Upper Extremity, Abdomen, and Pelvis
LOWER EXTREMITY
Muscles and Movement
Anterior Muscle Group: Responsible for walking and climbing.
Posterior Muscle Group: Performs plantarflexion of the foot.
Bones and Joints
Femur: The bone present in the thigh.
Blood Vessels
Common Femoral Artery: A continuation of the External Iliac Artery.
Common Femoral Vein: Formed by the union of Superficial and Deep Femoral Veins.
Popliteal Artery: A continuation of the Femoral Artery.
Popliteal Vein: Formed by the union of the Anterior Tibial Vein and Tibioperoneal Trunk.
Great Saphenous Vein: The longest vein in the body, drains into the Common Femoral Vein.
Small Saphenous Vein: Drains into the Popliteal Vein.
Deep Veins: Always accompany arteries.
Superficial Veins: Do not accompany arteries (e.g., Great Saphenous Vein).
Saphenofemoral Junction: Where the Great Saphenous Vein drains into the Deep Vein.
Superficial Femoral Vein: A continuation of the Popliteal Vein.
Dorsalis Pedis Artery: A continuation of the Anterior Tibial Artery.
Other Structures
Femoral Triangle:
- Base formed by the Inguinal Ligament.
- Common Femoral Vein runs most medially.
Subsartorial Canal (Adductor Canal): Contains the Superficial Femoral Artery.
Popliteal Fossa: Contains the Popliteal Artery and Popliteal Vein (vein is anterior to the artery). Does not contain the Deep Femoral Artery.
UPPER EXTREMITY
Muscles and Movement
Posterior Muscle Group: Involved in the extension of the arm.
Blood Vessels
Basilic Vein: Runs on the medial side of the arm, drains into the Brachial Vein.
Cephalic Vein: Seen on the lateral side of the arm, drains into the Axillary Vein.
Median Cubital Vein: Connects the Basilic and Cephalic Veins in the Cubital Fossa, commonly used for venipuncture.
Brachial Vein: Formed by the union of Radial and Ulnar Veins.
Axillary Artery: A continuation of the Subclavian Artery.
Brachial Artery: Divides into Radial and Ulnar Arteries in the Cubital Fossa.
Nerves
Axillary Nerve: Supplies the upper arm.
Median Nerve:
- Most medial structure within the Cubital Fossa.
- Found immediately under the Flexor Retinaculum on the lateral side of the Carpal Tunnel.
Radial Nerve: Most lateral structure in the Cubital Fossa.
Posterior Muscles of the Forearm: Supplied by the Radial Nerve.
Other Structures
Axilla:
- Anterior wall formed by the Pectoralis Muscle.
- Posterior wall formed by the Scapula and Subscapularis Muscle.
- Contains the Axillary Artery and Axillary Vein, but not the Brachial Vein.
ABDOMEN
Regions and Planes
Quadrants: Divided by the Vertical Median Plane and Horizontal Transumbilical Plane.
Regions: Divided by the Right and Left Midclavicular Planes (vertical), Subcostal Plane (horizontal), and Transtubercular Plane (horizontal).
Muscles
Anterolateral Abdominal Wall Muscles:
- Linea Alba
- Rectus Abdominis
- External Oblique
- Internal Oblique
- Transverse Abdominis
Posterior Abdominal Wall Muscles:
- Psoas Major
- Quadratus Lumborum
Blood Vessels
Aorta:
- Bifurcates into Right and Left Common Iliac Arteries at L4.
- Branches:
- Parietal (unpaired): Middle Sacral Artery
- Parietal (paired): 4 pairs of Lumbar Arteries
- Visceral (unpaired): Celiac Trunk, Superior Mesenteric Artery, Inferior Mesenteric Artery
- Visceral (paired): Middle Suprarenal Arteries, Renal Arteries, Gonadal Arteries
Celiac Trunk: Branches into Left Gastric Artery, Splenic Artery, and Common Hepatic Artery.
Inferior Vena Cava (IVC):
- Formed by the Right and Left Common Iliac Veins at L5.
- Direct Tributaries: Common Iliac Veins, Lumbar Veins, Right Gonadal Vein, Right Suprarenal Vein, Renal Veins, Hepatic Veins, Inferior Phrenic Veins
- Indirect Tributaries: Left Suprarenal Vein, Left Gonadal Vein
Renal Arteries:
- Right Renal Artery runs posterior to the IVC and Renal Vein.
- Left Renal Artery runs posterior to the Left Renal Vein.
Portal Vein: Formed by the Superior Mesenteric Vein and Splenic Vein.
Hepatic Veins:
- Left Hepatic Vein divides into Medial and Lateral segments.
- Middle Hepatic Vein divides the liver into Right and Left segments.
- Right Hepatic Vein divides into Anterior and Posterior segments.
Organs
Liver:
- Located in the Right Hypochondriac Region and part of the Epigastric Region.
- Ligaments:
- Falciform Ligament: Attaches the liver to the anterior abdominal wall and separates the right and left lobes.
- Ligamentum Venosum: Separates the Caudate Lobe from the Left Lobe.
- Ligamentum Teres: Separates the Quadrate Lobe from the Left Lobe.
- Lobes:
- Caudate Lobe: Separated from the Right Lobe by the IVC and from the Left Lobe by the Ligamentum Venosum.
- Quadrate Lobe: Separated from the Right Lobe by the Gallbladder and from the Left Lobe by the Ligamentum Teres.
- Porta Hepatis: Contains the Portal Vein, Hepatic Artery, and Common Hepatic Duct.
Gallbladder: Parts include the Neck, Body, and Fundus.
Bile Ducts:
- Intrahepatic Ducts join to form the Right and Left Hepatic Ducts.
- Right and Left Hepatic Ducts join to form the Common Hepatic Duct.
- Cystic Duct + Common Hepatic Duct = Common Bile Duct
Pancreas:
- Parts: Head, Neck, Body, Tail
- Relations: Spleen’s Hilus is related to the tail of the pancreas, and the pancreas extends from the duodenum to the spleen.
- Main Pancreatic Duct: Begins at the tail of the gland, runs through the body, and empties into the 2nd part of the duodenum.
Stomach:
- Parts: Cardia, Fundus, Body, Pyloric (with Lesser and Greater Curvatures)
- Spleen is posterior to the stomach.
- Gastroesophageal Junction: Junction between the stomach and esophagus.
Small Intestine: Parts include the Duodenum, Jejunum, and Ileum.
Large Intestine: Parts include the Cecum, Ascending Colon, Descending Colon, Transverse Colon, Sigmoid Colon, Rectum, and Anal Canal.
Kidneys:
- Posterior Relations: Diaphragm superiorly, Quadratus Lumborum and Psoas Muscles inferiorly.
- Anterior Relations:
- Right Kidney: Liver, 2nd part of Duodenum, Right Colic Flexure (Hepatic Flexure)
- Left Kidney: Left Suprarenal Gland, Stomach, Pancreas, Spleen, Left Colic Flexure (Splenic Flexure)
Ureters: Related to the Psoas Major Muscle.
Adrenal Glands:
- Right Adrenal Gland (Pyramidal shape): Limited by the liver laterally, IVC anteriorly, and diaphragm medially.
- Left Adrenal Gland (Semilunar shape): Left crus of the diaphragm medially, left kidney posteriorly and laterally, and anterior to the stomach and pancreas.
Colon:
- Ascending Colon: Superior to the liver/right hepatic flexure, lies posterior to the abdominal wall.
- Descending Colon: Left colic flexure, lateral border of the left kidney.
- Transverse Colon: Extends from the left colic flexure to the right hepatic flexure, has a peritoneum called the “Transverse Mesocolon.”
- Sigmoid Colon: Begins at the pelvic brim, enclosed with peritoneum called the “Sigmoid Mesocolon.”
Diaphragm:
- Portions: Sternal, Costal, Vertebral
- Openings:
- Caval Hiatus: T8
- Esophageal Hiatus: T10
- Aortic Hiatus: T12
Other Structures
Retroperitoneal Organs: Ascending Colon, Descending Colon, Pancreas, Ureters, Adrenal Glands, Kidneys, Esophagus
Intraperitoneal Organs: Small Intestine, Stomach, Spleen, Sigmoid Colon, Transverse Colon, Liver, Gallbladder
PELVIS
Structures
Pouch of Douglas: Peritoneal space located between the uterus and rectum.
True Pelvis: Walls formed by the Obturator Internus and Piriformis Muscles.
False Pelvis: Located above the pelvic brim.
Uterus:
- Innermost layer is the Endometrium.
- Lower third segment is known as the Cervix.
- Most superior portion is the Fundus.
- Fimbriae: Finger-like projections at the end of the fallopian tubes.
- Uterosacral Ligament: Attaches the uterus to the Sacrum.
Vesicouterine Space: Peritoneal space between the urinary bladder and the uterus.