Anatomy PA-CAT

Interspinous ligaments

Connect adjacent spinous processes.

When positioning a patient in the supine position for an extended time, what intervention helps prevent problems (contractures) with the ankle?

Dorsiflexion of 90° When positioning a patient (as for surgery), it is important to help prevent the development of contractures. In regard to the ankle, there should be dorsiflexion of 90°, ie, the ankle joint should be at a 90° angle. Interventions that can help in this instance include a padded footboard or a splint free of pressure. Dorsiflexion of 30° or 60° will not be sufficient to avoid ankle contractures. Dorsiflexion of 180° is too much dorsiflexion.

The liver has 4 lobes. Which lobes of the liver are directly separated by the falciform ligament?

Left lobe and right lobe The 4 lobes of the liver are the left, right, quadrate, and caudate lobes. Of these, the left and right lobes are the largest and are separated by the falciform ligament.

Cervical spondylosis

Reduced size of intervertebral foramina

The blood supply to the entire small intestine comes from branches of a single artery. Which artery is this?

Superior mesenteric artery The superior mesenteric artery supplies the entire small intestine, the ascending colon, and a portion of the transverse colon. The left gastric artery supplies the stomach. The coeliac artery supplies the liver, stomach, abdominal esophagus, spleen and the superior half of both the duodenum and the pancreas. The inferior mesenteric artery supplies the colon, starting with the middle of the transverse colon.

Anterior longitudinal ligament

A thick, fibrous band that runs along the anterolateral aspect of the vertebral bodies from C1 to the sacrum and limits extension of the spine. The other intervertebral ligaments limit flexion or rotation.

When positioning a patient, what intervention helps prevent problems (contractures) with the axilla?

Abduction When positioning a patient, there should be abduction of the axilla with a 10-15° forward flexion along with an external rotation. Positioning the patient in this manner will help to prevent contractures. This can be accomplished by suspending the arm from an IV pole or bedside table. The axilla would not be adducted, internally rotated, or neutrally rotated. These positions could cause contractures.

A patient dislocated their hip in a car accident. Anatomically, the head of the femur slipped out of a structure, leaving them in intense pain. What is the structure?

Acetabulum The acetabulum is the bony socket formed by the ilium, ischium, and pubis that houses the head of the femur to comprise the hip joint. The hip is one of the most complex joints; when it becomes dislocated, which takes an enormous amount of force, the patient is left immobile and in excruciating pain. Bearing weight on the joint becomes nearly impossible. The coccyx is the ending portion of the spine, commonly referred to as the tailbone. This bony structure has nothing to do with the patient's hip dislocation. The iliac crest is a portion of the pelvic bone, a bony ridge one might feel if they were to feel their "hip bone." The sacrum forms the posterior portion of the pelvis, and the sacral prominence is the anterior protrusion that forms the pelvic inlet. This part of the hip is not involved in a dislocation.

A 17-year-old male high school soccer player quickly changed direction during a game and averted a defensive player, scoring a goal, but also injuring himself. What type of injury might he have sustained with his quick start-stop directional change movement?

Anterior cruciate ligament tear Anterior cruciate ligament tears often happen with start-stop quick directional change movements in which the full weight of the body is on the knees. The most common causes of these injuries are sports such as football or soccer. After any injury to the knee, the best line of treatment is elevating above the heart, ice compression, and NSAIDs. Chondromalacia is a condition in which the articular cartilaginous portions of the knee begin to soften. This injury is often due to overuse or age-related changes within the joint of the knee. Physical therapy, ice, and NSAIDs are another common course of treatment. A meniscus tear is commonly caused by twisting movements of the knee. A malfunctioning meniscus can lead to catching or locking of the knee, pain, and swelling. Finally, a knee fracture often refers to the kneecap breaking. In certain cases, this break can tear the hamstring or quadriceps tendon. A minor break may require a cast to keep immobile, but serious ones may need surgery. A kneecap break is usually due to trauma, not movements.

The vertebrae are connected by a series of ligaments that limits movement and creates a cohesive spinal column. Which ligament prevents hyperextension of the spinal cord?

Anterior longitudinal ligament

A patient with difficulty swallowing is evaluated with a barium swallow study. The result is considered normal, although there are 3 areas of the esophagus that appear narrowed. These normal constrictions in the esophagus are formed by the compression of which structures on the esophagus?

Aortic arch, left main bronchus, diaphragm. Extending from the pharynx to the stomach, the esophagus enters the thorax in the midline but inclines to the left as it descends. In the superior mediastinum, it lies between the trachea and the vertebral column. The aortic arch pushes it towards the midline from the left. In the middle mediastinum, the left main bronchus also pushes on the esophagus from the left. The esophagus enters the abdomen through the esophageal hiatus of the diaphragm at the level of the T10 vertebra. This is where the diaphragm compresses the esophagus. The other answer choices (brachiocephalic trunk, left pulmonary artery, T10 vertebra, azygos vein, tracheal carina, inferior vena cava) are structures that do not compress the esophagus.

Orthostatic hypotension is a common side effect of many medications, causing a sudden decrease in blood pressure upon standing. Which division of the nervous system is responsible for such sudden changes in blood pressure seen in this condition?

Autonomic nervous system The autonomic nervous system is responsible for the automatic functions in the body that we are not consciously aware of and do not have control over. It specifically has many effects on smooth muscle and cardiac muscle, which cause the blood vessels to dilate and blood pressure to fall rapidly, as seen in orthostatic hypotension. The central nervous system contains the brain and spinal cord and has no implications in the sudden change in blood pressure. Somatic nervous system controls skeletal muscle, which is under voluntary control, but it does not affect muscles that would cause direct change in blood vessels. The sympathetic nervous system is most known for its role in fight or flight.

Supraspinous ligaments

Connect the tips of each spinous process

Ligamentum flavum

Connects lamina to lamina and resists the separation of vertebral lamina from abrupt flexion of the vertebral column.

The brain and the spinal cord make up the human central nervous system. Which region of the spine does the lower end of the spinal cord itself stop?

Conus medullaris The spinal cord is surrounded by bone (vertebrae). The lower end of the spinal cord ends in the conus medullaris. This area is slightly above the waist. Below this area, there is a group of nerve roots referred to as the cauda equina. The sensory tracts help to carry signals from different parts of the body to the brain.

A 49-year-old man presents due to groin pain. At his next appointment, the physician tells him the bulging is medial to the inferior epigastric vessels. What type of hernia is he diagnosed with?

Direct Hesselbach's triangle (also known as the inguinal triangle) is bounded by the inferior epigastric artery, the rectus abdominis muscle, and the inguinal ligament. Direct inguinal hernias are medial to the epigastric artery. Indirect inguinal hernias course through the deep inguinal ring. Femoral hernias are found in the medial aspect of the anterior thigh. Umbilical hernias are located at the umbilicus.

A 65-year-old man with a history of long-standing atherosclerotic disease slowly develops an atherosclerotic blockage of the right axillary artery below the level of the first rib but above the level of the subscapular artery. What is most likely to be true in this patient?

Direction of blood flow in the subscapular artery will be reversed. In this patient with long-standing atherosclerotic disease who slowly develops an atherosclerotic blockage of the right axillary artery above the level of the subscapular artery, blood flow to the limb will most likely be maintained through collateral circulation involving anastomoses around the scapula with the dorsal scapular, suprascapular, and subscapular arteries. Blood flow to the distal axillary artery through this collateral circulation entails a reversal of the normal direction of blood flow through the subscapular artery. If this patient had a slowly developing blockage of the axillary artery below the level of the subscapular artery, he would likely show signs of chronic limb ischemia, such as gangrene in the fingertips or ischemic arm pain when elevated, but the location of the blockage in this patient would allow this collateral circulation to develop. If the patient had a sudden blockage of the axillary artery at this point (e.g., sudden thrombosis or trauma), he would show signs of acute limb ischemia, such as pallor, cold, and no blood flow on Duplex ultrasound. The collateral circulation described above is only established slowly over time.

In an exam for peripheral vascular disease, the pulses of which arteries in the foot are normally palpated?

Dorsalis pedis artery, posterior tibial artery The dorsalis pedis pulse can be palpated midway along the slightly dorsiflexed foot, just lateral to the extensor hallucis longus tendons. The posterior tibial pulse can be detected by palpation of the foot posterior to the medial malleolus and medial to the calcaneal tendon. It is important to palpate both feet during a peripheral vascular exam to observe equal pulses bilaterally. The dorsalis pedis artery and posterior tibial artery are the most proximal arteries in the foot and have stronger, more detectable pulses than the other answer choices.

You are caring for a patient who sustained an injury to the insertion of the biceps brachii muscle. Based on this data, the injury is closest to which structure?

Elbow The biceps brachii muscle is the anterior muscle of the upper arm. An insertion refers to the end of the muscle that is attached to the movable bone. The radius is the insertion of the biceps brachii. The closest structure to the radius is the elbow. The clavicle, humerus, and shoulder are distal to the insertion of the biceps brachii muscle.

A 32-year-old man with a history of tricuspid valve replacement with a prosthetic valve as a child has been managed without complications for years on baby aspirin. He suddenly develops a toothache and finds that he needs a root canal. His history is a significant risk factor for developing what cardiac condition?

Endocarditis Endocarditis is a cardiac infection caused by bacteria that enter the bloodstream—often from the mouth—and settle within the cardiac space. These infections can occur in the valves of the heart or blood vessels of the heart. Because this patient has a history of valve replacement with prosthetic repair, he is more prone to bacteria settling in his valve. It is important for him to alert the dentist of his history so he can be started on prophylactic antibiotics. Untreated endocarditis can lead to further complications, such as a heart attack if the bacteria block enough of a blood vessel to the heart. A heart attack occurs when not enough blood—and consequently, oxygen—gets to the heart muscle. This loss of oxygen can lead to cardiac muscle death. Myocarditis is inflammation of the cardiac muscle itself. This is often caused by drugs, alcohol or viral infection and can lead to heart failure. Pericarditis is inflammation of the pericardium, the protective covering of the heart. Usually, these layers have a small amount of fluid protecting them, allowing the expansion and contraction of the heart without complication. Heart surgery, heart attack, HIV, cancer, or other health conditions can lead to this disorder.

Lordosis

Excessive curvature of the lumbar spine

Kyphosis

Excessive curvature of the thoracic spine

Surgical removal of the parotid gland is often performed to treat salivary gland tumors, 80% of which occur in the parotid glands. The branches of which nerve should be preserved during this surgery?

Facial nerve The branches of the facial nerve are embedded within the parotid gland, and they are at risk during parotidectomy. The facial nerve should be preserved in all cases unless there is evidence of malignant neoplasm within the nerve. The glossopharyngeal nerve, hypoglossal nerve, and vestibulocochlear nerve are not encountered in parotidectomies.

A 35-year old man is brought to the emergency department after a stab wound to his chest. Palpation of the radial pulse is rapid at 150 and the blood pressure is low at 75/30. The neck veins are also visibly engorged. The patient is suffering from cardiac tamponade. Which of the following is causing this patient's condition?

Fluid accumulation between the parietal and visceral serous pericardium. The pericardium of the heart is comprised of the outer fibrous layer (fibrous pericardium) and the inner layer (the serous pericardium). The serous pericardium is comprised of a parietal layer and the visceral layer that lays directly on the epicardial tissue. There is normally a small amount of pericardial fluid between the parietal and visceral layers of the heart to allow for reduced friction during regular heart beating. A rapid accumulation of fluid between the parietal and visceral layers of the pericardium (pericardial effusion) results in cardiac tamponade. An increase in pericardial fluid increases pressure around the heart which creates a restrictive envelope. The right heart, having less musculature and wall thickness than the left side, experiences greater structural distortion from the increased outer pressures. The overall effect is a distorted rocking motion, right-sided restriction, and poor cardiac output causing the constellation of signs and symptoms seen in this patient. This syndrome has a high mortality rate unless prompt diagnosis and intervention are performed.

The portal triad, made up of the hepatic artery proper, hepatic portal vein, and common bile duct, is often clamped to control bleeding from the liver in trauma surgery. If bleeding stops with this maneuver, it indicates injury to the hepatic artery or portal vein that may be causing bleeding. If the liver continues to bleed with clamping of the portal triad, what structure is likely injured?

Hepatic vein. Blood flow enters the liver through the hepatic artery (20-25%) and the hepatic portal vein (75-80%). If these vessels are not causing the bleeding, the only other blood vessels within the liver would be the hepatic vein and its branches or the inferior vena cava. The common hepatic duct drains bile and would not cause significant bleeding. The gastroduodenal artery is not involved in blood flow to or from the liver. The right hepatic artery is a branch of the hepatic artery. Bleeding from the right hepatic artery would be controlled by portal triad clamping.

A patient presents with a small bowel obstruction. The obstruction is located in a region of the small intestines that under histological examination contains numerous Paneth cells and Peyer's patches. Where is this obstruction located?

Ileum The final segment of the small intestine is the ileum. It is unique in having the highest concentration of Paneth cells and the presence of Peyer's patches. The first segment of the small intestine is the duodenum. The middle segment of the small intestine is the jejunum. The cecum is a pouch-like structure that signals the beginning of the large intestine. The rectum is the final section of the large intestine terminating at the anus.

What muscle helps to flex the thigh at the hip and is located somewhere other than one of the thigh compartments?

Iliopsoas The iliopsoas muscle is not considered a thigh muscle; it flexes the leg at the hip. The pectineus, sartorius, and quadriceps femoris muscles are all located in one of the three compartments of the thigh. The pectineus is in the medial compartment; the sartorius is in the anterior compartment; the quadriceps femoris is in the anterior compartment.

The hepatic circulation is controlled by the hepatic buffer control system. How does the hepatic buffer control system make adjustments to blood flow?

Increases blood flow in the hepatic artery in response to decreased blood flow to the portal vein. Blood supply to the liver is complex and involves both the hepatic system and the portal vein system. The hepatic artery is a direct branch from the celiac artery that is the first branch off of the abdominal aorta, supplying about 30% of the blood flow to the liver. The portal vein brings blood from the GI tract and supplies about 70% of the blood flow. If there is decreased flow from the portal vein system, the hepatic buffer control system increases the flow of the hepatic artery to keep a consistent amount of blood flow to the liver. This system only works with the hepatic artery making increasing adjustments to decreasing blood flow to the portal venous system. The hepatic artery does not decrease the flow if there is an increase in the portal venous flow. If the hepatic artery has either decreased or increased blood flow, this does not change the blood flow in the portal vein system.

A 20-year-old man is seen due to difficulty hearing in the right ear that started shortly after blunt force trauma to the head. An examination reveals a normal tympanic membrane without rupture, infection, or excess fluid. After further evaluation with advanced imaging, there is a disruption of the lenticular process.Which of the ossicles has been affected, causing hearing loss?

Incus There are three ossicles that lie directly medial to the tympanic membrane, constituting the middle ear. The incus is the middle bone and is made up of three parts, resembling an anvil. There is a body, a short process, and a long process. At the tip of the long process is the lenticular process, which attaches to the stapes, which is the smallest and most medial of the three bones and is shaped like a stirrup. The malleus is the most lateral bone that is connected to the incus and is shaped like a hammer. The cochlea and vestibule are the components of the inner ear and are connected to the ossicles of the middle ear via the round window membrane. Since ossicles transmit sound waves from the tympanic membrane to the inner ear, if there is any disruption in the chain of ossicles through trauma, birth defects, or diseases, this may lead to hearing loss.

The sacral plexus forms nerves that supply many of the muscles of the gluteal region. What nerve from this plexus branches off to supply the gluteus maximus muscle?

Inferior gluteal nerve While all of these are nerves arising in the sacral plexus, only the inferior gluteal nerve supplies the gluteus maximus muscle. The superior gluteal nerve, posterior femoral nerve, and pudendal nerve are other nerves that supply the area.

A 67-year-old man presents to his physician for an annual checkup. He has no acute complaints but does admit to increased fatigue, an unintentional 20-pound weight loss over the last year, and worsening constipation. He has never had a prior colonoscopy. On physical exam, he appears pale and fatigued but not acutely ill. His abdomen is soft and non-tender. His rectal exam is heme-occult negative. He is referred for a colonoscopy where the endoscopist discovers a circumferential mass in his sigmoid colon. He undergoes resection of the sigmoid colon, Hartmann's pouch creation, and diverting colostomy. What vessel was divided to complete this sigmoid resection and what is its embryological origin?

Inferior mesenteric artery; hindgut The colon is primarily supplied by the superior mesenteric artery and the inferior mesenteric artery. The sigmoid colon is supplied by the inferior mesenteric artery, the territory of which starts at the splenic flexure of the colon. The inferior mesenteric artery is hindgut in embryologic origin. The cecum, ascending, and transverse colon are supplied by the superior mesenteric artery, which is midgut in origin.

An infant with a history of upward force on arm during delivery presents with total claw hand. The lumbricals appear to be flexing the metacarpophalangeal (MCP) joints, as well as extending the distal and proximal interphalangeal joints. These findings result from damage to which aspect of the brachial plexus?

Lower trunk Damage to the lower trunk (C8-T1 roots) (Klumpke palsy) is commonly seen in infants with upward force on the arm during delivery and in adults with forceful arm trauma, such as grabbing onto a tree branch to break a fall. Klumpke palsy presents with total claw hand, as seen in this patient. Damage to roots (C5, C6, C7) damages the long thoracic nerve, which classically presents with winged scapula. Damage to the upper trunk would lead to Erb palsy (waiter's tip hand). Damage to the posterior cord would cause wrist drop.

Avascular necrosis of the head of the femur can be caused by specific damage to what crucial artery supplying the hip joint?

Medial circumflex femoral artery Damage to the medial circumflex femoral artery can result in avascular necrosis to the head of the femur. This is a branch of the profunda femoris artery along with the lateral circumflex femoral artery. The femoral artery is the large supplying artery to each of these vessels.

A patient presents with characteristics of carpal tunnel syndrome. Which nerve is most likely damaged?

Median nerve The median nerve is most frequently affected in the carpal tunnel. Typically, the median nerve enters the hand through the carpal tunnel. The extensor carpi ulnaris extends and adducts the hand. The thenar muscles are on the lateral part of the palm. The trapezius stabilizes the upper back.

A patient presents with injury to the left upper limb. On physical exam, the patient shows inability to flex the forearm at the elbow and loss of sensation to the lateral forearm. What nerve has been damaged?

Musculocutaneous The musculocutaneous nerve innervates the flexors of the forearm, including coracobrachialis, biceps brachii, and brachialis. Biceps brachii is responsible for supination of the forearm. Damage to the musculocutaneous nerve is responsible for loss of forearm flexion and supination of the forearm and for loss of lateral forearm sensation. The axillary nerve innervates the deltoid muscle, which is responsible for abduction (from 15-110°), adduction, flexion, extension, and medial and lateral rotation of the arm. The radial nerve is responsible for extension of the wrist and thumb. The ulnar nerve is responsible for flexing the forearm, flexing the hand, adducting the hand and thumb.

The lymphatic vessels from the spleen directly drain to which lymph nodes?

Pancreaticosplenic lymph nodes Lymphatic vessels that drain the spleen emerge from the hilum of the spleen and drain directly to the pancreaticosplenic lymph nodes, which also gather lymph from the pancreas, on its way to the celiac nodes. The hepatic lymph nodes receive lymph from the superficial lymphatics of the anterior aspects of the diaphragmatic and visceral surfaces of the liver. The phrenic lymph nodes receive lymph from the superficial lymphatics of the posterior aspects of the diaphragmatic and visceral surfaces of the liver. The superior mesenteric lymph nodes receive lymph from the small intestine and the large intestine up to the left colic flexure, as well as other lymph nodes and lymphatics from structures supplied by the SMA.

Which of the following bones make up the lambdoidal suture?

Parietal bones and occipital bone The parietal bones and the occipital bone articulate to form the lambdoidal suture. The right and left parietal bones make up the sagittal suture. The parietal bones and the frontal bone form the coronal suture. No suture is formed with the articulation of the temporal bones and the frontal bone.

The superior and inferior gluteal arteries are branches of the internal iliac artery. What muscle separates these two arteries as they exit the greater sciatic foramen?

Piriformis While each of these is a gluteal muscle, it is the small piriformis muscle that separates the superior gluteal artery and the inferior gluteal artery in the deep portion of the gluteal region. The gluteus medius and the gluteus minimus muscle are more superficial muscles. The quadratus femoris is more inferior to the greater sciatic foramen.

An obese 65-year-old woman with a history of osteoporosis reports acute onset low back pain that radiates down the back of the right thigh to the lower right leg. What vertebral injury would most likely cause her symptoms?

Posterolateral herniation of the L4-L5 IV disc. This patient's acute onset low back pain that radiates down her thigh and leg is characteristic of a posterolateral herniation of the L4-L5 intervertebral (IV) disc that results in compression of the right sciatic nerve, a condition called sciatica. This location of this patient's symptoms involves the roots of the sciatic nerve at the spinal levels of L4-S1, not the L2-L3 IV disc. Almost all IV disc herniations are posterolateral, where the annulus fibrosis is not supported by the anterior or posterior longitudinal ligaments, not anterolateral. An anterolateral herniation of the L5-S1 IV disc would not compress the spinal roots and give rise to the particular symptoms seen in this patient. The characteristics and distribution of this patient's symptoms are consistent with an IV disc herniation. A vertebral body fracture would present much more dramatically and more seriously. An X-ray may show some non-specific findings, such as osteoporosis of the vertebrae or narrowing of the spinal foramina, but a herniated IV disc is a soft tissue injury and does not show up on X-ray as a vertebral body fracture would. Acute low back pain caused by an L3 vertebral body fracture or an L5 vertebral body fracture would likely be caused by a traumatic event localized to the midline of the back and would involve a substantial portion of the spinal cord at that level, rather than just the spinal roots.

Which of the following is the correct sequence of respiratory structures of the bronchial tree?

Primary bronchi, secondary bronchi, tertiary bronchi, bronchioles In each bronchial tree, the primary bronchi branch into 5 secondary bronchi. The secondary bronchi, which serve to channel the air to the lungs, are divided into tertiary bronchi. These smaller segments are further branched off into bronchioles, also known as the terminal bronchi. There are at least 25,000 bronchioles in the lungs, each leading to an alveolus, the basic functional unit of the respiratory system.

What male reproductive structure completely encircles the urethra?

Prostate The prostate is an exocrine gland of the male reproductive system that secretes a slightly basic fluid, which is released together with the semen, seminal vesicle fluid, and sperm. Its alkalinity protects the viability and activity of the sperm. The prostate is known for completely encircling the urethra.

After delivering twins, a G4P4005 patient presents to the OB/GYN 2 weeks postpartum with constipation and pressure in the vagina and pelvis. Upon digital examination, the OB/GYN feels a bulging mass deep within the vaginal cavity. What is the most likely diagnosis?

Rectocele Signs and symptoms of a rectocele may be pressure in the vagina or pelvis, constipation, or a bulging mass within the vagina. Risk factors include multiple births, long labor, episiotomy, and straining to pass bowels. Internal hemorrhoids are a common complication of childbirth, and they are associated with bloody stools and a burning sensation during bowel movements. A perineal laceration with or without an episiotomy can be a risk factor for developing a rectocele, which is a laceration that extends from the vagina through varying degrees of the tissue of the perineum. In extreme cases, these stretch all the way to the anus. A uterine prolapse is the cervix and uterus protruding into the vaginal cavity and at times outside of the vagina into the external environment.

Which of the following kidney structures houses the renal pyramids?

Renal medulla The renal pyramids are the cone-shaped tissues in the kidneys. The pyramids are made of tubules that are mainly responsible for urine transport from the cortex towards the calyx. There are about approximately 7-10 pyramids situated in the innermost portion of the kidney, which is referred to as the medulla. The renal sinus is a cavity of the kidney that houses the renal pelvis, renal calyces, nerves, and fat. The renal cortex is the outermost part of the kidney, which contains the renal corpuscles and tubules, excluding the loop of Henle. It also houses some blood vessels and collecting ducts. The renal pelvis is the proximal portion of the ureter, serving as a funnel. Cognitive Level: Knowledge

Which of the following urinary system sequences is the exact urine excretion pathway?

Renal pelvis, ureters, bladder, urethra The urinary system is responsible for the excretion of the body's digestive and metabolic wastes through different processes, such as filtration, re-absorption, and tubular secretion. The output of these processes is the urine, which is a compound of soluble wastes, excess bodily waters, sugars, and other toxic compounds. It flows following the pathway: renal pelvis of the kidneys, then the ureter, bladder, and released from the body via the urethra.

A breast cancer survivor patient with a history of axillary node dissection presents with symptoms consistent with scapular winging: primarily, inability to abduct the arm above the horizontal plane. She describes pain that radiates the length of her arm and numbness and tingling that extend into the hand. What portion of the brachial plexus has been damaged?

Roots. Damage to the serratus anterior is responsible for the patient's clinical presentation (winged scapula). Winged scapula represents an injury to the long thoracic nerve, weakening the serratus anterior muscle. The long thoracic nerve is derived from brachial plexus roots C5, C6, and C7. Damage to upper trunk (C5-C6 roots) is known as Erb palsy or "waiter's tip hand" due to the arm hanging by the patient's side (adducted), medially rotated, with arm extended and pronated. Damage to the lower trunk (C8-T1 roots) is known as Klumpe palsy and presents as total claw hand (distal and proximal interphalangeal joints extended). Damage to the posterior cord would damage the extensors of the arm (axillary and radial nerves), causing wrist drop.

Posterior longitudinal ligament

Runs along the posterior aspect of the vertebral column and prevents hyperflexion of the spine.

A child reports increased back pain and an uneven gait that gives the healthcare provider the impression that one limb is shorter than another (but they are equal when directly measured)? What is the most likely diagnosis?

Scoliosis Scoliosis is the lateral bending of the vertebral column, often in the thoracic area. Kyphosis is a curvature of the spine that produces a "humpback." Lordosis is having a "hollow back," or being "bent backward." Some describe it as a sway back. It may be caused by poor posture. Spina bifida is a defect of the vertebral column where L5 or S1 fails to develop normally, leaving a hole or dimple.

If the trapezius were paralyzed, the patient is still able to raise the arm above the head, albeit with difficulty. Which muscle aids this action?

Serratus anterior muscle The serratus anterior muscle can act to superiorly rotate the scapula, which is necessary to raise the arm over the head. The infraspinatus primarily causes external rotation of the humerus. The pectoralis major adducts and medially rotates the humerus. The latissimus dorsi adducts, internally rotates, and extends the humerus. It also acts in rotation of the torso. The rhomboid major retracts and stabilizes the scapula. Injury to this muscle can present as winging of the scapula.

A patient comes to the emergency department due to abdominal pain. After questioning the patient, the physician orders imaging scans to be done, as they suspect the patient just has severe constipation. Upon arrival of the scans, where should the doctor look to see if their diagnosis is correct?

Sigmoid colon The doctor should look at the sigmoid colon. As leftover waste moves via peristalsis through the large intestine, water is continuously being reabsorbed, causing the waste to become more solid. The structure furthest away from the beginning of the large intestine should have the most solid form of the waste. The sigmoid colon is the further structure that stores the stool when no more water will be absorbed by the body. The rectum does not store anything; it is the structure that stool passes through before it is expelled. Remember that the rectum is usually empty. The descending colon and the ascending colon are parts of the large intestine but do not store stool. Waste and water absorption are still taking place in these areas.

Despite our necessary balance of homeostasis, there are parts of the body that thrive in extreme environments. Where in our body can the highly-erosive hydrochloric acid be found?

Stomach Gastric juice, a mixture of digestive enzymes and hydrochloric acid, is produced by the stomach. About 3-4 liters of this acidic digestive juice is made per day. Mucous and bicarbonate mix together to ensure the stomach does not consume itself with its acidity. The esophagus is a long hollow muscular tube that moves food from the mouth into the stomach via peristalsis. The esophagus can sometimes have an acidic environment, but it is not designed for this; an acidic environment can lead to esophagitis if not addressed. The large intestine absorbs most of our intake of water and salts. It is the ending of our digestive system with stool exiting through the anus. All digestion starts in the mouth. This orifice begins the digestive process of carbohydrates by the enzymes found in our saliva. An acidic environment in the oral cavity can lead to ulcers.

What vessel is adjacent to the head of the pancreas?

Superior mesenteric artery The uncinate process is a projection of the inferior part of the pancreatic head that extends medially to the left and immediately posterior to the superior mesenteric artery (SMA). The rest of the head of the pancreas rests posteriorly on the inferior vena cava (IVC), the right renal artery and vein, and the left renal vein. None of the other vessels lie adjacent to the head of the pancreas. The short gastric veins drain blood from the stomach to the splenic vein and lie adjacent to the tail of the pancreas. The left renal artery arises off the abdominal aorta immediately below the SMA at the level of the body of the pancreas and runs along the tail. The splenic vein drains blood from the spleen and stomach and terminates at the joining of the SMV to form the portal vein adjacent to the neck of the pancreas.

A 55-year-old male patient with a 20-year smoking history is experiencing pain, swelling, and weakness in the right arm and hand, with slight difficulty seeing out of the right eye. Computerized tomography (CT) imaging confirms the diagnosis of a Pancoast tumor. What structure is being compressed?

Sympathetic trunk This 55-year-old male patient with a long smoking history is at high risk for developing lung cancer. These right-sided symptoms are commonly caused by the mass effect of a Pancoast tumor. This kind of tumor is located in the superior lobe of the right lung, obstructing thoracic inlet structures. A large mass in the superior lobe of the right lung can result in compression of the sympathetic trunk, leading to right-sided Horner's syndrome: facial flushing on the right side and miosis (constriction) of the right pupil with respect to the left in bright light. The compression of the sympathetic trunk by this tumor would occur at the level of the thoracic inlet, so there would likely be anhidrosis of the entire right side of the face. Vagus nerve compression could cause autonomic changes, since it provides parasympathetic innervation to the heart and much of the digestive tract. If the compression is at the level of the recurrent laryngeal nerve or more proximal, hoarseness can result. Compression of the trachea would ultimately lead to stridor and difficulty breathing. Compression of the common carotid artery could lead to decreased cerebral blood flow, presenting similarly to carotid artery stenosis.

In human beings, the lower respiratory system divides into the right and left lungs. Which of the following is true about the number of lobes in each lung?

The right lung has 3 lobes, while the left lung has 2. The right lung is bigger and has 3 lobes. The left lung has only 2 lobes. These lobes are encased in the thoracic cavity, suspended at the inferior of the trachea. It branches to the bronchi first, then into bronchioles.

There are four major muscles located in the anterior compartment of the leg. Which muscle is the strongest of these muscles responsible for dorsiflexion of the foot?

Tibialis anterior The tibialis anterior muscle is the strongest muscle responsible for the dorsiflexion of the foot. The extensor digitorum longus, extensor hallucis longus, and fibularis tertius are part of the anterior compartment, but they are not strong foot dorsiflexors.

When the forearms are extending at the elbow, which muscle is the prime mover?

Triceps brachii When the forearms are extending, the triceps brachii is the prime mover; the brachialis is the antagonist. Neither the biceps brachii nor the brachioradialis is involved in extension of the arm.

Which of the following bodily structures is possibly defective if a person is incontinent?

Urethral sphincter muscles The urethra is the opening that releases urine. It has both involuntary and voluntary control. The external sphincter muscle is responsible for the voluntary control of voiding. The pudendal nerve regulates this conscious innervation of the external urethral sphincter. The internal urethral sphincter is the smooth muscle that constricts the urethral opening. The lumbar plexus maintains its function. Incontinence is most likely associated with problems in both urethral muscle sphincters. The trigone is a triangle-shaped, smooth muscle area of the urinary bladder formed by the 2 openings and internal urethral orifice. It is sensitive when stretched to a certain degree, and it sends signals to the brain that it needs to be emptied. The detrusor muscle is the muscle in the lining of the urinary bladder. The transversus abdominis is the deepest abdominal muscle that helps in supporting posture and protecting internal organs.

Which of the following anatomical landmarks indicates where the navel is situated?

Ventral Ventral is an anatomical term for direction relating to the anterior. Cranial is an anatomical term relating to the head. It is also known as cephalic. Dorsal is an anatomical term for direction relating to the posterior. Inferior is an anatomical term for relative direction below a reference point. Cognitive Level: Knowledge

Scoliosis

lateral curvature of the spine