Open Ended Questions Flashcards
(63 cards)
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.