Open Ended Questions Flashcards
Describe the contents of the carpal tunnel
The carpal tunnel is a narrow passageway in the wrist, formed by the carpal bones (floor and sides) and the flexor retinaculum (roof). It contains:
1. Median nerve – Provides sensation to the lateral three and a half fingers and motor function to some hand muscles.
2. Nine flexor tendons – Surrounded by synovial sheaths to reduce friction:
• Four flexor digitorum superficialis (FDS) tendons
• Four flexor digitorum profundus (FDP) tendons
• One flexor pollicis longus (FPL) tendon
3. Pronator quadratus
Compression of the median nerve within this space can lead to carpal tunnel syndrome, causing pain, numbness, and weakness in the hand.
Describe the posterior wall of inguinal canal
Posterior Wall: In an inner point of view it can be divided into 3 parts:
-medial: Strongest part of the posterior wall. Its constituted by transversalis fascia and reinforced by henle and lacunar ligaments.
-central: Constituted only by transversalis fascia and not reinforced by any ligament. Located medially to the epigastric vessels. Its the location where acquired hernia occurs.
-lateral: Constituted by transversalis fascia and reinforced by the vertical fibers of the henle ligament. It’s the location where the congenital hernia occurs.
Describe the Tricuspid Valve
Tricuspid valve is so called because it consists of three cusps or leaflets called anterior, posterior and septal cusps. The base of each cusp is attached to the fibrous ring called an annulus fibrosus that surrounds the right atrioventricular orifice. The fibrous ring helps to maintain the shape of the orifice. Cusps come together in areas called commissures, to be inserted into the annulus. The free margins of the cusps are attached to the chordae tendineae which are the cords arising from the respective papillary muscles. Anterior papillary muscle binds to the anterior and posterior cusps, posterior papillary muscle binds to the posterior and septal cusps, septal papillary muscle binds to septal and anterior cusps of the tricuspid valve.
During atrial systole, the tricuspid valve is open and the cusps project into the right ventricle however during the ventricular systole papillary muscles contract and pull on chordae tendineae to close the tricuspid valve so it prevents the backflow of the blood into the atrium.
Describe the location of the thymus, its relations with other anatomical structures and its microscopic anatomy
Located at the mediastinum and at the level of the most superior part of the manubrium of the sternum and completely covered by cervical fascia. Made by two lobes and these two lobes are connected by a structure called isthmus. The right and left lobes of the thymus might slightly extend to the right and left pleural cavities.
Relations with other structures:
Posteroinferiorly: Heart
Superiorly: thyroid cartilage
Laterally: Internal jugular vein and superior vena cava
Posteriorly: Aortic arch, pulmonary trunk and trachea
MICRO: It is a specialized organ of the immune system which has a vital role in maturation of T lymphocytes.
Composed of 2 main tissue types: cortex and medulla
In the cortex located in the periphery, there are densely packed lymphocytes and epithelial cells to support these lymphocytes. There are two subtypes of epithelial cells in the cortex:
○ Squamous thymic epithelial cells are important in the formation of the thymus blood barrier and the formation of the corticomedullary barrier.
○ Stellate thymic epithelial cells that form the cytoreticulum.
In the medulla located in the center there are less lymphocytes but a great number of epithelial cells. There are three subtypes of epithelial cells in the medulla:
○ The squamous thymic and stellate thymic cells of the medulla have similar functions to their counterparts in the cortex.
○ Hassall corpuscles. They are the concentrically arranged flattened epithelial cells.
Macro anatomy of the transverse colon
It’s slightly inferior to the 3rd part of the duodenum. It corresponds to transverse mesocolon which is the most superior part of the mesentery. Anteriorly covered by the peritoneum forming the lesser sac and there is the presence of the epiploic foramen allowing the communication between greater and lesser sacs. Postero inferiorly jejunum is present. The bulk of the transverse colon is supplied by the middle colic artery. Right and left flexures, extremities of the colon are supplied by right and left colic arteries respectively.
Macro anatomy of trachea
The trachea, also known as the windpipe, is a cartilaginous tube that connects the larynx to the bronchi of the lungs, allowing the passage of air. It extends from C6 to T4, T5 vertebral level. Has hyaline cartilage shaped like C that supports the structure of the trachea. Trachea is located posteriorly to the manubrium and body of sternum. It bifurcates into two common bronchi proximal to pulmonary hilum.
The median nerve: origin, course and territory of innervation
Originating from the medial and lateral branches of the brachial plexus. Travels underneath the teres major and then between biceps and brachioradialis to reach cubital fossa where it gives lateral branches to pronator teres. Then it travels between the palmaris longus and flexor carpi ulnaris and travels through the carpal tunnel. It innervates the flexors of arm and forearm except flexor carpi ulnaris (innervated by ulnar nerve).
Describe the femoral orifice/ring:
It’s the opening of the femoral canal which is the most medial segment of femoral sheath found in the femoral triangle. It has an oval shape. At this level deep inguinal lymph nodes are found which are the sites for intestinal hernias. Superiorly there is the inguinal ligament is found, medially the lacunar ligament, laterally the femoral vein, posteriorly the lateral parts of pubis. Potential site for femoral hernias.
Internal surface of the right ventricle
The internal surface of the heart ventricles is lined with trabeculae carneae, which are irregular muscular ridges that help maintain efficient blood flow and prevent suction that could impair function. Additionally, papillary muscles project into the ventricles and are connected to the chordae tendineae, which anchor the atrioventricular (AV) valves, preventing prolapse during contraction.
• Left Ventricle:
• Thicker myocardial wall (about 3× thicker than the right ventricle)
• Circular in cross-section
• Generates high pressure to pump oxygenated blood into the systemic circulation (aorta)
• Right Ventricle:
• Thinner wall compared to the left ventricle
• More crescent-shaped in cross-section
• Pumps deoxygenated blood at lower pressure into the pulmonary circulation (pulmonary artery)
Microscopic anatomy of the spleen
The spleen is constituted by two pulps: red and white. The white pulp, responsible for lymphoid activity of the spleen, has the cortical and medullary regions similar to lymph nodes. The red pulp has functions by destroying the old erythrocytes. The liver has its own population of splenic macrophages. The spleen has a higher capillary mass compared to other abdominal viscera due to its lymphoid/blood-cleaning function.
Describe the inguinal canal
The inguinal canal is a passage in the lower anterior abdominal wall located just above the inguinal ligament. It starts from the internal inguinal orifice, extends medially and inferiorly through the abdominal wall layers and ends in the external inguinal orifice. This canal is about four to six centimeters in length. Within the inguinal canal there are ilio-inguinal nerves, spermatic cord or the round ligament of the uterus pass. Spermatic cord contains cremaster muscle, vas deferens and the genital branch of genitofemoral nerve. The round ligament sustains the anteversion angle during pregnancy.
Describe the aortic valve
The aortic valve is a semilunar valve normally has three cusps called the anterior, right and left cusps which are connected to the fibrous skeleton of the heart. Right and left cusps have little holes on their parietal surface that marks the beginning of the coronary arteries. The aortic valve separates the left ventricle from the ascending aorta. The cusps project into the artery and are completely open during ventricular systole. During the relaxation of the myocardial wall (diastole), the elastic wall of the aorta pushes the blood back into the heart. However, the shape of the cusps and the aortic root activate the cusps and completely close the aortic valve. This process prevents the reverse blood flow into the left ventricle.
Describe the cruciate ligaments
They are two: anterior and posterior cruciate ligaments
-Anterior cruciate ligament originates from the anterior intercondylar area of the tibia and ascends posterolaterally to attach to the posteromedial aspect of the lateral femoral condyle.
-Posterior cruciate ligament originates from the posterior intercondylar area of the tibia and ascends anteromedially to attach on to the anterolateral surface of the medial femoral condyle.
-Anterior cruciate ligament protects the tibia from anterior translation while the posterior one protects it from posterior translation.
-They are poorly vascularized thus they don’t properly repair upon tear.
-They are supported by medial and lateral segments surrounding the knee joint
Describe the inner layer of prostatic urethra
It’s the portion of the urethra that directly passes through the prostate. It’s a common path for both reproductive and urinary pathways. In the posterior inner surface, at the level of urethral crest there are seminal colliculus which is an embryologic remnant and two ejaculatory ducts which are responsible for the release of the ejaculatory fluid.
Describe the second part of duodenum
It’s also called the descending part of the duodenum and this part of the duodenum is retroperitoneal.
It has minor and major duodenal papillae:
-Minor one corresponds to the opening of the accessory pancreatic duct while the major one is corresponding to the opening of the bile duct. It’s the first part of the GI Tract that receives the bile and the exocrine pancreas secretions. It is supplied by the pancreatico-duodenal vessels which are the branches of the common hepatic and gastroduodenal vessels.
Gross anatomy of pleurae
There are two layers of pleura being the visceral covering the lungs and parietal layers. Between these layers there is virtual space. In case of rupture of the parietal pleura and the fluid buildup in this virtual space the respiratory failure might occur due to the inability in expanding the lungs. At the level of parietal pleura and mediastinum there are recesses found, the most important one being the costo-diaphragmatic recess allowing the expansion of the lungs especially during deep breaths. Two layers of the pleura join together proximal to the pulmonary hilum forming the pulmonary ligament.
Describe the sinoatrial node
It’s located at the level of terminal sulcus at the right atrium. It confers the sinus rhythm. It’s a primary pacemaker made by pacemaker cells. It triggers an electrical impulse that initiates the contraction of atria. Can’t be seen with the naked eye necessitating a microscope.
Subscapularis muscle: origin, insertion and innervation
Origin: Subscapular fossa of the scapula
Insertion: Lesser tubercle of the humerus
Innervation: Upper and lower subscapular nerves (C5-C7)
Function: Medially rotates and stabilizes the shoulder joint. It is a rotator cuff muscle
Structure of intervertebral disc
-It is made by inner nucleus palposus which is mainly constituted of proteoglycans. Outer annulus fibrosus is constituted of collagen fibers. Annulus fibrosus functions in anchoring the intervertebral disc to the vertebra and prevents its herniation while nucleus palposus functions like a cushion withstanding the compressive forces.
Ligaments of the liver
1- Falciform Ligament: The ligament that attaches the liver to the anterior abdominal wall and divides the liver into the left lobe and right lobe. It contains the ligamentum teres.
2- Coronary Ligament: The ligament that attaches the liver to the inferior surface of the diaphragm. It forms the bare area of the liver where there is no peritoneal covering.
3- Left and Right Triangular Ligaments: They are the lateral extensions of the coronary ligament. They secure the liver’s left and right lobes to the diaphragm.
4- Hepatoduodenal Ligament: The ligament that connects the liver to the first part of duodenum (superior duodenum). It contains the portal triad (hepatic artery, portal vein, common bile duct)
5- Hepatogastric Ligament: The ligament that connects the liver to the stomach. It is the part of the lesser omentum.
Describe the macroscopic anatomy of the pylorus
Pylorus is the distal end of the stomach where it connects with the duodenum. It has 3 main components:
Pyloric Antrum: It is the wider part proximal to the stomach. The pyloric glands are located in the antrum of the pylorus. They secrete gastrin produced by their G cells. Gastrin is a peptide hormone primarily responsible for enhancing gastric mucosal growth, gastric motility, and secretion of hydrochloric acid (HCl) into the stomach.
Pyloric Canal: It’s the narrow part connecting the pyloric antrum with the duodenum.
Pyloric Sphincter: It is a circular muscle that surrounds the junction of the pyloric canal and the duodenum and acts as a valve by regulating the passage of the chymus from stomach to the duodenum.
Describe the structure of Bowman’s Capsule
It is the key component of the renal corpuscle which is a part of nephron. Renal corpuscle is made by two components: glomerulus which are the clusters of capillaries and the bowman’s capsule surrounding the glomerulus.
Bowman’s capsule has 2 layers, inner and outer:
inner layer: It’s the visceral layer that is in contact with glomerulus. Formed by podocytes. It has finger-like processes called the foot processes which form filtration slits.
outer layer: It’s the parietal layer made of simple squamous epithelium that lines the outer part of the capsule.
These two layers together form the primary urine.
Supraspinatus Muscle
origin: supraspinous fossa of the scapula
insertion: greater tubercle of humerus
innervation: suprascapular nerves (C5-C6)
Function: stabilizes and abducts the glenohumeral (shoulder) joint. It is a rotator cuff muscle.
Describe the elastic membrane of the larynx
-Quadrangular membrane,which is quadrangular in shape and made of thin, elastic connective tissue and it is located above the conus elasticus. It extends from the lateral margins of the epiglottis to the arytenoid cartilages and its superior margin gives rise to aryepiglottic fold. The free inferior border of this ligament is the vestibular ligaments also known as the false vocal cords. This membrane also contributes to the delimitation of the superior part of the laryngeal cavity.
-Conus elasticus, also known as the cricothyroid membrane, is made of yellow elastic tissue. Inferiorly it attaches to the superior surface of the cricoid arch and lamina then ascends to the internal surface of the thyroid cartilage. The superior margins of conus elasticus are free and they form the vocal ligaments which are the bases of vocal folds. It functions to maximize the airflow from the trachea to rima glottidis when speaking.
Explain the uterine angles
There are two types of uterine angles:
Anteversion: It is a forward angulation of the cervix and vagina. And it is usually 90 degrees.
Anteflexion: It is a forward angulation of the cervix and the uterine body. It is usually around 120-125 degrees.
These angles may vary with genetic variations or pregnancy.
Describe the bicuspid (mitral) valve
It is located between the left atrioventricular orifice. It is called bicuspid/mitral valve due to the presence of two cusps: anterior and posterior cusps/leaflets. The base of each cusp is secured to the fibrous ring that surrounds the orifice and free edges are attached to the respective papillary muscles of the left ventricle via chordae tendineae. During ventricular systole leaflets are closed to prevent the backflow to the atrium due to papillary muscle contraction pulling the chordae tendineae.
Sternocostal Joints
They are the synovial joints between the sternum and costal cartilages of the ribs with the exception of the first joint which is considered as a primary cartilaginous joint. These joints are between the true ribs and sternum thus there are 7 pairs: 1st joint is between the 1st rib and the manubrium of the sternum 2nd-6th joints are between the respective ribs and the body of the sternum The 7th joint is between the 7th rib and the xiphoid process of the sternum. These joints are supported by 3 ligaments which are called intraarticular sternocostal ligaments, radiate sternocostal ligament and xiphocostal ligament. These joints function in mechanical ventilation by allowing the gliding of the costal cartilages with the ribs.
Describe the relationship between uterine artery and the ureters:
Uterine artery passes the ureter superiorly at the level of the cervix, below the isthmic part of the uterus. This is the reason why ureters are at risk in pelvic and gynecological surgeries. The distal/pelvic ureters are supplied by the branches of the uterine and vesical arteries which are the branches of the internal iliac artery.
Describe the foramen ovale and the ductus arteriosus
Foramen Ovale: It is a small hole in the septum between two atria in the fetal heart. Function: The oxygenated blood coming from the placenta via the umbilical vein is reaching to the right atrium and then to the left atrium bypassing the fetal lungs which are not fully developed yet to reach the left ventricle. This way the oxygenated blood is distributed in the body with aorta. This hole closes with the first breath and becomes the fossa ovalis.
Ductus Arteriosus: It is a temporary blood vessel connecting the pulmonary artery to aorta, in the fetal heart in order to divert the majority of the blood away from undeveloped fetal lungs. With the first breath, due to the oxygen exchange this vessel constricts and becomes a fibrous ligament called the ligamentum arteriosum.
Describe axillary lymph nodes, their arrangements, relationships
Axillary lymph nodes drain the entire upper limb, breasts and the trunk above the umbilicus. There are 5 classes of axillary lymph nodes:
Anterior: Drains the skin and the muscles of the anterolateral aspect of the trunk superior to umbilicus and lateral quadrants of the breasts.
Posterior: Found anterior to the subscapularis muscle
Lateral: Found posteromedially to the axillary vein. Drains majority of the upper limb
Central: Found at the base/center of the axilla, interspread into the adipose tissue. Most important one because it receives lymph from anterior, posterior, lateral groups.
Apical: Found at the lateral aspects of the first rib, extends to the apex of the axilla. Drains into the subclavian lymph trunk.
Describe the microscopic anatomy of the esophagus
It has 4 distinct layers:
1- Mucosal Layer: It has a non-keratinized stratified squamous epithelium continuous with the pharynx. Squamous epithelium becomes columnar at the esophagogastric junction.
2- Submucosal Layer: It connects the mucosal layer to the muscular layer. It has esophageal glands, submucosal nerve plexus (Meissner) and larger blood vessels.
3- Muscular Layer: The third layer is formed by circular and longitudinal muscle fibers. The longitudinal layer is generally thicker than the circular layer; both are described as follows:
• Inner circular muscle fibers: These fibers are continuous superiorly with the fibers of the cricopharyngeal part of the inferior constrictor and inferiorly with oblique fibers of the stomach.
• Outer longitudinal muscle fibers: The longitudinal muscle fibers form a continuous coat around the whole of the esophagus except posterosuperiorly, 3-4 cm below the cricoid cartilage; here, they diverge as 2 fascicles that ascend obliquely to the anterior aspect of the esophagus
The proximal one-third of the esophagus consists primarily of striated muscle. Smooth muscle predominates in the distal portion.
4- Adventitial Layer: Outermost fibrous layer.
Describe the microscopic anatomy of the duodenum
- Mucosa:
• Lined by simple columnar epithelium with goblet cells that secrete mucus.
• Contains villi and microvilli, which increase the surface area for absorption.
• Crypts of Lieberkühn (intestinal glands) are present at the base of the villi, containing cells like Paneth cells, which secrete antimicrobial peptides. - Submucosa:
• Contains Brunner’s glands, which secrete alkaline mucus to neutralize acidic chyme from the stomach. - Muscularis externa:
• Composed of an inner circular and outer longitudinal smooth muscle layer responsible for peristalsis. - Serosa/Adventitia:
• The duodenum has both serosa (in parts) and adventitia (where it is retroperitoneal), providing structural support.
Describe the macro anatomy of the left lung
It is smaller than the right lung due to the presence of the heart.
It has 2 lobes: upper and lower lobes and it’s missing the middle lobe that is present in the right lung.
These lobes comprise 8 segments, 4 in the upper lobe and 4 in the lower lobe:
upper lobe segments: apicoposterior, anterior, superior lingula and inferior lingula APASLIL
lower lobe segments: superior, anteromedial, posterior and lateral: SAMPL
The visceral pleura forms invaginations called fissures in both lungs. The left lung has 1 complete and 1 incomplete fissure.
Describe the cornua of the uterus and its relationship with nearby structures
Also known as the uterine horns, it is found at both lateral extremities between the fundus and the body of the uterus where fallopian tubes exit to meet with ovaries. It provides attachment for ovarian ligament which is located posteroinferiorly to the fallopian tubes and for round ligament which is located anteroinferiorly to the fallopian tubes.
Peripheral attachments of the diaphragm
Anterior: xiphoid process of sternum and costal margins
Posterior: lumbar vertebra via the medial and lateral arcuate ligaments.
Lateral: 11th and 12th ribs.
The diaphragm has 2 surfaces: thoracic and abdominal
thoracic surface contacts with the serous membranes of the heart (pericardium) and the lung (pleura)
The abdominal surface contacts directly with the liver, stomach and spleen.
Describe the lesser omentum
The lesser omentum is a double-layered peritoneal fold that connects the lesser curvature of the stomach and the proximal part of the duodenum to the inferior surface of the liver. It is a component of the lesser sac and forms part of the anterior wall of the omental bursa.
• Hepatogastric ligament (upper part): A thin, broad sheet connecting the liver to the lesser curvature of the stomach.
• Hepatoduodenal ligament (lower part): A thickened portion that extends between the liver and the first part of the duodenum, containing the portal triad (portal vein, hepatic artery proper, and bile duct).
It serves as a pathway for vessels and nerves between the liver and stomach while also helping to maintain the position of the stomach.
Describe the relationship between the bladder and the terminal parts of the ureters
The ureters extend from the hilum of the kidney and go caudally along with the anterior surface of the sublumbar muscles.
In women ureters are posterior to ovaries and uterine arteries before turning medially. Then they extend anteriorly to the vagina and along with the vaginal wall before connecting to the base of bladder
In men ureters are crossed by vas deferens anteriorly before they connect to the base of the bladder.
They connect to the base of the bladder posterolaterally, and they pass the bladder muscularis obliquely and form a valve preventing the reflux of the urine from the bladder.
The ureters have the same basic structure as the base of the bladder: They have a fibrous adventitia and adipose tissue, thin outer and inner longitudinal and a more prominent middle smooth muscle fibers. The musculature becomes thicker when it’s proximal to the bladder.
Describe the microscopic anatomy of lymph nodes
The convex surface of the lymph node is where afferent lymph vessels enter, and the concave surface where the efferent lymph vessels exit.
It is divided into 3 main regions:
Cortex: Outermost layer It contains subcapsular sinus, cortical sinus and lymphoid nodules Although the B and T cells are both present, B cells are more abundant The lymph from afferent canal flows from subcapsular sinus to cortical sinus.
Paracortex: Located deep into cortex lymphoid nodules are absent T cells are abundant in its stroma It has a unique type of venules called high endothelial venules that most of the lymphocytes enter the lymph nodes via these channels.
Medulla: Deepest layer - Its divided functionally and histological into two regions: medullary cord and sinuses
These cords are populated by plasma, B and T cells.
Macro anatomy of the pharynx
Pharynx is a hollow, uneven and a median organ that is a common tract of both respiratory and digestive pathways. It is approximately 14-15 cm long and it connects to the esophagus at the level of the sixth cervical vertebra. Its inferior border is defined anteriorly by the inferior margin of the cricoid cartilage. From cranial to caudal it is divided into three main parts:
-Nasopharynx: It is located between the pharyngeal vault and the superior surface of the soft palate. It connects to eardrums via auditory tubes. It is horizontal during swallowing, separating the nasopharynx from the bolus.
-Oro-pharynx: It is between the inferior surface of the soft palate and horizontal plane that is superior to the hyoid bone at the level of the third cervical vertebra.
-Laryngopharynx: It is located between the horizontal plane that is superior to hyoid bone at the level of the third cervical vertebra and esophagus which is located at the level of the sixth cervical vertebra.
Microanatomy of the pharynx
- Externally it is covered by the adventitious layer which contains vascular-nervous structures inside
- More internally there is the muscular layer formed by striated muscles, there are two types of muscles:
- Constrictors: Superior, middle and inferior constrictor muscles
- Elevators: Stylopharyngeus, Salpingopharyngeus and palatopharyngeus muscles.
-In between the muscular and the mucosal layers there is the pharyngobasilar membrane that separates these aforementioned two layers and it contains a rich amount of elastic fibers.
-Most internally there is the mucosal layer:
- In nasopharynx: Characterized by the ciliated pseudostratified columnar epithelium with
goblet cells - In oropharynx and laryngopharynx: Characterized by the non-keratinized stratified
squamous epithelium
Greater Omentum
The greater omentum is a large, double-layered peritoneal fold that originates from the greater curvature of the stomach and the proximal part of the duodenum. It descends over the small intestines as a fatty apron before folding back upward to attach to the transverse colon and mesocolon.
• Upper part (gastrocolic ligament): Attached to the greater curvature of the stomach and the proximal duodenum.
• Lower part (omental apron): Covers the intestines and loops back to attach to the transverse colon.
It contains fat, blood vessels, lymph nodes, and immune cells. The greater omentum serves as an important fat storage site, cushions abdominal organs, and plays a defensive role by localizing infections and preventing the spread of peritoneal inflammation. Its mobility allows it to adhere to damaged or inflamed areas, aiding in containment and healing.
Topography and relationship to the abdominal portion of the ureter
- Ureters run retroperitoneally and in close contact to the anterior surface of the psoas major muscle.
- They are crossed by gonadal vessels, so testicular vessels in men and ovarian vessels in women anteriorly; crossed by the lateral nerves of the thigh and the genitofemoral nerves posteriorly.
- Abdominal part of the right ureter lies posteriorly to the second part of the duodenum while the abdominal part of the left ureter lies posteriorly to the jejunoduodenal flexure.
- Their initial part corresponds to the lower pole of the kidneys laterally, more distally the right ureter corresponds to the ascending colon and the left ureter corresponds to the descending colon. -Medial to the right ureter there is the IVC whereas medially to the left ureter there is the abdominal aorta.
Describe the pelvic relations of ureter
In the passage from the abdominal ureter to the pelvic ureter; the right ureter passes over the external iliac vessels whereas the left ureter extends like a bridge over the common iliac vessels. Ureters descend into pelvis inferomedially, they are first located retroperitoneally then intraperitoneally and at this level they are crossed anteriorly by the collateral branches of the internal iliac vessels such as umbilical artery, obturator artery, superior vesical arteries.
In males: At the level of the last portion of the pelvic ureter, ureters pass posteriorly to vas deferens and located between the ipsilateral seminal vesicle and the base of the bladder.
In females: First portion of the pelvic ureter extends posteriorly to the ovaries defining the posterior limit of the ovarian fossa. The ureters run lateral to the upper part of vagina and the neck of uterus
Posterior relationship of the head of the pancreas
Located posteriorly to the head of the pancreas, there is the bile duct and within the head the bile duct and the pancreatic duct merge together to form the hepatopancreatic ampulla (of Vater) which marks the entry point of the bile into the second portion of the duodenum. Posteriorly to the pancreatic head there is also the inferior vena cava.
Liver Macroanatomy
The liver is located in the upper quadrant of the abdominal cavity at the level of the 5th intercostal space. The superior, anterior, posterior, and right surfaces of the liver are continuous with each other and all related to the anterior abdominal wall and the diaphragm. The only clear border is the inferior border and on the inferior surface there is an H shaped fissure.
The right vertical line of this H is formed by: anteriorly by the gallbladder, posteriorly by the IVC. They are incomplete with the caudate process in between.
The left vertical line of the H is formed by: anteriorly by the round ligament of the liver, posteriorly by the ligamentum venosum.
The horizontal line of the H is formed by: The porta hepatis (hilum) with the quadrate lobe anteriorly, caudate lobe posteriorly
Liver Microanatomy
Liver is made up of microscopical units called the lobules which are roughly hexagonal in shape. The lobules consist of rows of liver cells called hepatocytes which radiate out from a central point. Between the cords of hepatocytes there are the large diameter capillaries called the sinusoids and they are lined by the endothelial cells. The hepatocytes lie adjacent to the sinusoids and also lie adjacent to the canaliculi into which bile is secreted.
The hepatic artery, hepatic portal vein and the bile duct cluster together at the corners of the lobule forming the portal triad. At the center of the lobule there is the central vein located. Blood flows out of sinusoids into the central vein and its transported out of the liver.
Transversus Abdominis Muscle
origin: costal cartilages of 7th-12th ribs, thoracolumbar fascia, iliac crest and inguinal ligament
insertion: pubic crest and pecten pubis
innervation: anterior branches of 7th to 12th thoracic nerves and ilioinguinal nerves
function: compresses and provides support to adjacent abdominal structures
Brachioradialis Muscle
origin: superior 2/3rd of the lateral supracondylar ridge of the humerus
insertion: lateral aspect of the distal part of the radius
innervation: radial nerve
function: flexes forearm at the elbow joint
Psoas Major Muscle
origin: transverse processes of the L1-L5 vertebrae and the vertebral bodies of the T12-L5 vertebrae. insertion: lesser trochanter of femur
innervation: anterior branches of 1-2-3 lumbar nerves
function: flexes thigh at hip joint and flexes the trunk.
Kidney macroanatomy
They have a bean-like shape in which an anterior (directed anterolaterally) and posterior (directed posteromedially) surface, a medial and lateral border and two poles, inferior and superior, can be identified. The upper pole has a more rounded curvature than the sharper lower pole. The lateral border is convex.
Midway along the medial border is the renal hilum. The hilum leads to a large cavity, called the renal sinus, within the kidney. The ureter and renal vein leave the kidney, and the renal artery enters the kidney at the hilum.
The left kidney tends to be larger. The kidneys occupy the renal lodge in the retroperitoneal space and are located at a height of T12 to L2. The right kidney is affected by the relationship with the liver and is slightly lower than the left kidney. Through the intermediation of adipose tissue and the layers of the renal fascia, the kidneys relate to other structures.
Anterior surface of kidneys
The relationship of the upper pole with the adrenal is the same.
Right: A narrow portion at the upper extremity is in relation with the right suprarenal gland. A large area just below this and involving about three-fourths of the surface, lies in the renal impression on the inferior surface of the liver, and a narrow but somewhat variable area near the medial border is in contact with the descending part of the duodenum. The lower part of the anterior surface is in contact laterally with the right colic flexure, and medially, as a rule, with the small intestine. The areas in relation with the liver and small intestine are covered by peritoneum; the suprarenal, duodenal, and colic areas are devoid of peritoneum.
Left: A small area along the upper part of the medial border is in relation with the left suprarenal gland, and close to the lateral border is a long strip in contact with the renal impression on the spleen. A somewhat quadrilateral field, about the middle of the anterior surface, marks the site of contact with the body of the pancreas, on the deep surface of which are the lienal vessels. Above this is a small triangular portion, between the suprarenal and splenic areas, in contact with the postero-inferior surface of the stomach. Below the pancreatic area the lateral part is in relation with the left colic flexure, the medial with the small intestine. The areas in contact with the stomach and spleen are covered by the peritoneum of the omental bursa, while that in relation to the small intestine is covered by the peritoneum of the general cavity
Posterior surface of kidneys
The two kidneys relate to structures of the posterior abdominal wall. Both the right and left kidneys are crossed by the 12th rib. On the right, the 12th rib delimits the upper 1/3 of the kidney, on the left, half of the kidney. Then the right kidney relates to the last intercostal space, the left one to both the last intercostal space and the 11th rib.The relationship with the coast is not direct due to the intermediation of the diaphragm.
Medial-lateral direction of the kidney relates to the psoas major, the quadratus lumborum and the transversus abdominis aponeurosis. Three nerves run inferior to the 12th rib: the subcostal, iliohypogastric, and ilioinguinal nerves.
Kidney adipose capsule
The perirenal fat is composed of adipose tissue that surrounds the kidneys and the suprarenal glands. It envelopes the fibrous capsules and is held tight around the organs via the renal fascia. This fat is typically more solid than normal fat.
The capsule represents an important element of fixity, in fact in case of rapid weight loss and reduction of adipose tissue, there may be a descent of the kidneys.
The adipose tissue is located partly inside the renal lodge, between the two layers of the renal fascia. The renal fascia is the continuation of the transverse fascia following its splitting. There are two layers: one anterior (pre-renal fascia, anterior layer of renal fascia or Gerota’s fascia) which passes in front of the kidney and one posterior (post-renal fascia, posterior layer of renal fascia or Zuckerkandl’s fascia) which passes posteriorly to the kidney.
The posterior fascia extends medially by inserting into the anterolateral aspect of the vertebral bodies. The anterior fascia continues medially and constitutes a fascial plane that passes in front of the aorta and the IVC. The renal lodge is closed at the top by the fusion of the two layers which continue with the diaphragmatic fascia. Below, the sheets remain separate keeping the lodge open.
Relationship of the kidney with the peritoneum
Anteriorly the kidneys are covered by peritoneum, the right and left kidney create different relationships.
In the anterior aspect of the right kidney, there are two planes of peritoneal coverage, one superior and the other inferior. Supero-laterally, the peritoneum reflects on the liver. Between the two organs there may be a hepatorenal peritoneal fold which forms the bottom of Morrison’s pouch. The link between the two organs is given by the hepatorenal ligament. Medially, the peritoneum reflects on the duodenum forming a fold called the hepatoduodenal ligament and, inferiorly on the colon, the lower pole of the right kidney is almost never covered by peritoneum.
The left kidney relates upwards and laterally to the visceral aspect of the spleen through the parietal peritoneum. It is also related to the duodenojejunal flexure through the submesocolic parietal peritoneum and, through the omental bursa, to the stomach.
Finally, the peritoneum acts as a means of fixation of the kidney by keeping it attached to the posterior abdominal wall.
Kidney microanatomy
Each kidney is held in place by connective tissue, called renal fascia, and is surrounded by a thick layer of adipose tissue, called perirenal fat, which helps to protect it. A tough, fibrous, connective tissue renal capsule closely envelopes each kidney and provides support for the soft tissue that is inside.
The outer, reddish region, next to the capsule, is the renal cortex. This surrounds the region called the renal medulla. The renal medulla consists of a series of renal pyramids, which appear striated because they contain straight tubular structures and blood vessels. The wide bases of the pyramids are adjacent to the cortex and the pointed ends, called renal papillae, are directed toward the center of the kidney. Portions of the renal cortex extend into the spaces between adjacent pyramids to form renal columns. The cortex and medulla make up the parenchyma, or functional tissue, of the kidney.
The central region of the kidney contains the renal pelvis, which is located in the renal sinus, and is continuous with the ureter. The renal pelvis is a large cavity that collects the urine as it is produced. The periphery of the renal pelvis is interrupted by cuplike projections called calyces. A minor calyx surrounds the renal papillae of each pyramid and collects urine from that pyramid. Several minor calyces converge to form a major calyx. From the major calyces, the urine flows into the renal pelvis; and from there, it flows into the ureter.
Each kidney contains over a million functional units, called nephrons, in the parenchyma (cortex and medulla). A nephron has two parts: a renal corpuscle and a renal tubule. The renal corpuscle consists of a cluster of capillaries, called the glomerulus, surrounded by a double-layered epithelial cup, called the glomerular capsule. An afferent arteriole leads into the renal corpuscle and an efferent arteriole leaves the renal corpuscle. Urine passes from the nephrons into collecting ducts then into the minor calyces.
The juxtaglomerular apparatus, which monitors blood pressure and secretes renin, is formed from modified cells in the afferent arteriole and the ascending limb of the nephron loop.
Cortical kidney
The renal cortex is the outer portion of the kidney between the renal capsule and the renal medulla. In the adult, it forms a continuous smooth outer zone with a number of projections (cortical columns) that extend down between the pyramids. It contains the renal corpuscles and the renal tubules except for parts of the loop of Henle which descend into the renal medulla. It also contains blood vessels and cortical collecting ducts.
The renal cortex is the part of the kidney where ultrafiltration occurs. Erythropoietin is produced in the renal cortex.
Organization of the medullary portion of the kidney
The medulla is made up of a variable number of renal pyramids (12-15) which are triangular structures with base facing outward and apex facing the renal sinus. The renal sinus is a deep cavity which forms the continuation of the hilum and contains numerous divisions of renal vessels and the first channels of the excretory system surrounded by adipose tissue. It is bounded by the renal parenchyma, the apex of the renal pyramid is called the renal papilla and projects into the lumen of the corresponding minor calyx. These represent the openings of the papillary ducts through which the urine formed in the parenchyma is poured into the lumen of the calyces to reach the renal pelvis. It is divided into the internal medulla and external medulla. The external medulla is in turn divided into the internal band and the external band. The inner medulla contains only thin segments of the loop of Henle, the inner band both thin and thick segments, and the outer band only thick segments.
Ligaments of the stomach
The ligaments of the stomach are peritoneal folds that connect the stomach to adjacent organs and structures, providing support and allowing for the passage of vessels and nerves. They include:
- Gastrohepatic or hepatogastric ligament (part of the lesser omentum)
• Connects the stomach to the liver.
• Contains the left and right gastric vessels. - Gastrosplenic (gastrolienal) ligament
• Connects the stomach to the spleen.
• Contains the short gastric and left gastroepiploic vessels. - Gastrocolic ligament (part of the greater omentum)
• Connects the stomach to the transverse colon.
• Contains the gastroepiploic vessels. - Gastrophrenic ligament
• Connects the stomach to the diaphragm.
• Provides structural support but contains few significant vessels.
These ligaments contribute to the stability of the stomach and facilitate the transmission of blood vessels and lymphatics.
Inner configuration of the bladder
The inner configuration of the urinary bladder consists of several important features:
- Mucosa:
• Lined by transitional epithelium (urothelium), allowing for stretch and recoil.
• Folds called rugae are present when the bladder is empty and disappear as it fills. - Trigone:
• A smooth, triangular area at the base of the bladder between the openings of the ureters and the internal urethral orifice.
• Unlike the rest of the bladder, it lacks rugae and remains smooth to facilitate efficient urine flow. - Ureteral Openings:
• Located at the upper corners of the trigone, where urine enters the bladder from the ureters. - Internal Urethral Orifice:
• Located at the lower apex of the trigone, where urine exits into the urethra.
• Surrounded by the internal urethral sphincter (involuntary smooth muscle). - Submucosa:
• A connective tissue layer beneath the mucosa, supporting blood vessels and nerves. - Detrusor Muscle:
• A thick, smooth muscle layer arranged in longitudinal, circular, and oblique layers.
• Responsible for bladder contraction during micturition.
These features collectively allow the bladder to store and expel urine efficiently while accommodating volume changes.
Stomach macroanatomy
The stomach is a muscular, J-shaped organ in the upper abdomen between the esophagus and the small intestine. It can be divided into four main regions:
1. Cardia: The area where the esophagus connects to the stomach, containing the lower esophageal sphincter that prevents acid reflux.
2. Fundus: The dome-shaped upper part that stores undigested food and gases.
3. Body: The largest central portion, responsible for mixing and churning food with digestive enzymes and acids.
4. Pylorus: The lower region that narrows into the pyloric canal, leading to the small intestine. It includes the pyloric sphincter, which controls the release of stomach contents.
The stomach’s inner surface has folds called rugae, which allow expansion when food is present. Its walls consist of four layers: mucosa, submucosa, muscularis externa, and serosa.
Flexor digitorum superficialis (innervation, action, origin and insertion)
Flexor Digitorum Superficialis
- Origin:
• Humeroulnar head: Medial epicondyle of the humerus and coronoid process of the ulna
• Radial head: Anterior oblique line of the radius - Insertion: Middle phalanges of the 2nd to 5th fingers (each tendon splits before insertion)
- Action: Flexes the proximal interphalangeal (PIP) joints of the 2nd to 5th fingers. Assists in flexion of the metacarpophalangeal (MCP) joints and the wrist
- Innervation: Median nerve
Gross anatomy of the prostate
The prostate is a walnut-shaped, fibromuscular gland located in the male pelvis, surrounding the proximal urethra below the bladder.
- Location:
• Inferior to the bladder and anterior to the rectum
• Superior to the urogenital diaphragm - Structure:
• Composed of glandular and fibromuscular tissue
• Enclosed by a fibrous capsule - Zones:
• Peripheral Zone: Largest, surrounds the distal prostatic urethra and is the most common site for prostate cancer
• Central Zone: Surrounds the ejaculatory ducts
• Transitional Zone: Surrounds the proximal urethra, commonly involved in benign prostatic hyperplasia (BPH)
• Anterior Fibromuscular Stroma: Non-glandular, fibromuscular tissue - Surfaces:
• Base: Broad superior surface adjacent to the bladder
• Apex: Narrow inferior part resting on the urogenital diaphragm
• Anterior surface: Faces the pubic symphysis
• Posterior surface: Related to the rectum (accessible during digital rectal examination) - Functions:
• Secretes fluid that contributes to seminal fluid
• Provides nutrients and enzymes to support sperm motility
Rotator cuff muscles: origin, insertion and action
The rotator cuff consists of four muscles that stabilize the shoulder joint and assist in arm movements.
- Supraspinatus
• Origin: Supraspinous fossa of the scapula
• Insertion: Greater tubercle of the humerus
• Action: Initiates and assists in abduction of the arm (first 15 degrees, after 15 degrees deltoid muscles become increasingly more effective), stabilizes the glenohumeral joint - Infraspinatus
• Origin: Infraspinous fossa of the scapula
• Insertion: Greater tubercle of the humerus
• Action: External (lateral) rotation of the arm, stabilizes the shoulder joint - Teres Minor
• Origin: Lateral border of the scapula
• Insertion: Greater tubercle of the humerus
• Action: External (lateral) rotation of the arm, assists in adduction, stabilizes the shoulder - Subscapularis
• Origin: Subscapular fossa of the scapula
• Insertion: Lesser tubercle of the humerus
• Action: Internal (medial) rotation of the arm, stabilizes the shoulder joint
These muscles work together to maintain the head of the humerus within the glenoid cavity during arm movements, providing stability and preventing dislocation.
