51. ANSWER: D The mucosa of the lining epithelium of the ductus (vas) deferens forms low longitudinal folds. It is lined by a pseudostratified epithelium. 52. ANSWER: C The sacrotuberous ligament (called also the great or posterior sacrosciatic ligament) is situated at the lower and back part of the pelvis. The lower border of the ligament was found to be directly continuous with the tendon of origin of the long head of the biceps femoris in approximately 50% of subjects. (Which means that the biceps femoris could therefore act to stabilize the sacroiliac joint via the sacrotuberous ligament). Another question asked in the board exam is, “Which of the following arteries is contained in thr sacrotuberous ligament?” The sacrotuberous ligament contains the coccygeal branch of the inferior gluteal artery. 53. ANSWER: B The superior hypogastric block is an injection into the collection of hypogastric nerves that pass to and from all pelvic viscerae such as the bladder, uterus, vagina, prostrate, and rectum. Letter A is wrong because the pelvic splanchnic nerves or nervi erigentes are splanchnic nerves that arise from sacral spinal nerves S2, S3, S4 to provide parasympathetic innervation to the hindgut. Letter C is wrong. The anterior divisions of the lumbar nerves, sacral nerves, and coccygeal nerve form the lumbosacral plexus, the first lumbar nerve being frequently joined by a branch from the twelfth thoracic. For descriptive purposes this plexus is usually divided into three parts: lumbar plexus, sacral plexus, pudendal plexus and none of these plexuses supply pain fibers to the uterus. Letter D is definitely wrong. However if your uterus is in the thoracic cavity it may be innervated by the upper sympathetic trunk. He he he... 54. ANSWER: A A germ cell is any biological cell that gives rise to the gametes of an organism that reproduces sexually. In embryology, the gonadal ridge (or genital ridge) is the precursor to the gonads. The gonadal ridge initially consists mainly of mesenchyme and cells of underlying mesonephric origin. 55. This PRC question is erroneous. Letters A & D are possible answers. The vitelline arteries give rise to the celiac artery, superior mesenteric artery, and inferior mesenteric artery. 56. ANSWER: D Haversian canals (sometimes Canals of Havers, named after British physician Clopton Havers) are a series of tubes around narrow channels formed by lamellae. This is the region of bone called compact bone. Osteons are arranged in parallel to the long axis of the bone. The Haversian canals surround blood vessels and nerve cells throughout the bone and communicate with osteocytes in lacunae (spaces within the dense bone matrix that contain the living bone cells) through canaliculi. They usually run at obtuse angles to the Haversian canals Letter C is wrong because Sharpey's fibres (bone fibres, or perforating fibres) are a matrix of connective tissue consisting of bundles of strong collagenous fibres connecting periosteum to bone. They are part of the outer fibrous layer of periosteum, entering into the outer circumferential and interstitial lamellae of bone tissue. Letter B is wrong because the Canaliculi are microscopic canals between the various lacunae of ossified bone. The radiating processes of the osteocytes project into these canals. These cytoplasmic processes are joined together by gap junctions. Osteocytes do not entirely fill up the canaliculi. The remaining space is known as the periosteocytic space, which is filled with periosteocytic fluid. 57. ANSWER: D Basophils usually make up the fewest number of circulating WBCs and are thought to be involved also in allergic reactions.
58. ANSWER: D Ang golgi complex ay maihahantulad sa isang post office: it concentrates, packages, and labels items which it then sends to different parts of the cell. 59. ANSWER: D The myeloblast is the first recognizable cell of the granulopoiesis. Granulopoiesis constitutes 40-80% of the hemopoietic cells in the normal bone marrow. So, the closest answer to this question is Letter D. 60. ANSWER: B The amorphous ground substance of connective tissue’s principal constituents are large carbohydrate molecules or complexes of protein and carbohydrate, called glycosaminoglycans (formerly known as mucopolysaccharides). One of these carbohydrates is hyaluronic acid. 61. ANSWER: C During muscle contraction, the A-bands do not change their length whereas the I-bands and the Hzone shorten. This causes the Z lines to come closer together. 62. ANSWER: B The tunica externa, also known as the tunica adventitia, is the outermost layer of a blood vessel, surrounding the tunica media. It is mainly composed of COLLAGEN and is supported by external ELASTIC lamina. The collagen serves to anchor the blood vessel to nearby organs, giving it stability. 63. ANSWER: B The tunica externa, also known as the tunica adventitia, is the outermost layer of a blood vessel, surrounding the tunica media. It is mainly composed of COLLAGEN and is supported by external ELASTIC lamina. The collagen serves to anchor the blood vessel to nearby organs, giving it stability. 64. . 65. ANSWER: C Monocytopoiesis is the process which leads to the production of monocytes (and, subsequently, macrophages) in the bone marrow. It can be induced by macrophage colony-stimulating factor. It is a component of myelopoiesis. 66. ANSWER: B Letter C is wrong. The keratinocytes of the stratum lucidum do not feature distinct boundaries and are filled with eleidin (not eukeratin), an intermediate form of keratin. The stratum basale is primarily made up of basal keratinocyte cells, which can be considered the stem cells of the epidermis. They divide to form the keratinocytes of the stratum spinosum, which migrate superficially. Other types of cells found within the stratum basale are melanocytes (pigmentproducing cells), Langerhans cells (immune cells), and Merkel cells (touch receptors). 67. ANSWER: D Upon inhalation, gas exchange occurs at the alveoli, the tiny sacs which are the basic functional component of the lungs. The alveolar walls are extremely thin (approx. 0.2 micrometers). These walls are composed of a single layer of epithelial cells (type I and type II epithelial cells) close to the pulmonary capillaries which are composed of a single layer of endothelial cells. The close proximity of these two cell types allows permeability to gases and, hence, gas exchange. 68. ANSWER: D 69. ANSWER: D. During the proliferative phase, increasing amounts of estrogen secreted from the developing follicle stimulates the mitotic cell division of the stratum basalis layer of the endometrium. These cells differentiate and mature into stratum functionalis cells and replace the tissue that was lost during the previous menstrual cycle. Estrogen also stimulates significant angiogenesis which increases the blood supply to provide energy and raw materials for cell growth and nourishment for the implanted zygote
70. ANSWER: D. During the proliferative phase, increasing amounts of estrogen secreted from the developing follicle stimulates the mitotic cell division of the stratum basalis layer of the endometrium. These cells differentiate and mature into stratum functionalis cells and replace the tissue that was lost during the previous menstrual cycle. Estrogen also stimulates significant angiogenesis which increases the blood supply to provide energy and raw materials for cell growth and nourishment for the implanted zygote. 71. ANSWER: A The smooth muscle of the lower esophagus and the lower esophageal sphincter are derived from the mesenchyme of the somites surrounding the foregut. The vagina is fibromuscular. 72. ANSWER: C The prostate gland has fibroelastic stroma containing randomly orientated smooth muscle bundles. 73. ANSWER: C 74. ANSWER : D Cross-striations in the cardiac muscle are apparent but they are not as regular nor as prominent as those of skeletal muscle. In fibrocartilage, Type II collagen makes up 40% of its dry weight and are arranged in cross-striated fibers. 75. This PRC question is erroneous because all of the above structures are present in the stomach bed. 76. ANSWER: C The prostatic utricle by the way is often asked in the boards primarily because it is the male homologue of the female uterus and vagina. 77. ANSWER: C Letter A & B are wrong because the perilymph is similar to ordinary interstitial fluid and fills the spaces of the bony labyrinth surrounding the membranous labyrinth. 78. ANSWER: C Letter A & B are wrong because the perilymph is similar to ordinary interstitial fluid and fills the spaces of the bony labyrinth surrounding the membranous labyrinth. 79. ANSWER: C Barium double meal contrast and xray 80. ANSWER: A The coronary sinus is a collection of veins joined together to form a large vessel that collects blood from the heart muscle. 81. ANSWER: A Its origin is at the lower margin of the teres major muscle and a continuation of the brachial vein. 82. ANSWER: A Letter C is wrong. The ulnar nerve originates from the C8-T1 nerve roots (and occasionally carries C7 fibres) which form part of the medial cord of the brachial plexus. Letter D is wrong. Three muscles compose the thenar eminence: Abductor pollicis brevis (innervated by median nerve), Flexor pollicis brevis (can be innervated by both ulnar and median nerves), and Opponens pollicis (innervated by median nerve).The ulnar nerve is exclusively responsible for the innervations of the hypothenar eminence that includes: Opponens digiti minimi, Flexor digiti minimi brevis, Abductor digiti minimi. 83. ANSWER: C The pericardiacophrenic artery is a long slender branch of the internal thoracic artery. It accompanies the phrenic nerve, between the pleura and fibrous pericardium, to the diaphragm, to which it is distributed. It anastomoses with the musculophrenic and inferior phrenic arteries.
84. ANSWER: A The nerve to obturator internus is a nerve that innervates the obturator internus and gemellus superior muscles. 85. ANSWER: D Nerves to the obturator internus (L5, S1, and S2) innervates the Obturator internus muscles. 86. ANSWER: D Rectus sheath is a long fibrous sheath in the center of the anterior abdominal wall. It encloses the rectus abdominis and pyramidalis muscles and contains the anterior rami of the lower six thoracic nerves, superior and inferior epigastric vessels and lymph vessels. 87. ANSWER: C Major parts of the nephron are the renal corpuscle (glomerulus), the proximal convoluted tubule, the loop of Henle, and the distal convoluted tubule. 88. ANSWER: C The esophagus does not contain lymph nodes. Instead its lymph nodes are found just along the side of the esophagus (peri-esophageal lymph node.) 89. ANSWER: D The ciliary body receives parasympathetic innervation from the oculomotor nerve. 90. ANSWER: C Ribonucleoproteins can be stained with Bernhard staining technique. RNA identification is further ascertained by NaOH-treatment. 91. ANSWER: This PRC question is erroneous. Letter A is wrong because solitary or single lymphatic nodule is a feature of the small intestine and the large intestine but not the stomach. Letter C is wrong. The gastric glands of the stomach are located in the mucosa. The submucosa of the stomach is generally unspecialized. Letter D is correct. A simple columnar epithelium is a columnar epithelium that is uni-layered. In humans, a simple columnar epithelium lines most organs of the digestive tract including the stomach, small intestine, and large intestine. Simple ciliated columnar epithelia line the uterus. Simple columnar epithelia are further divided into two categories: non-ciliated and ciliated. Letter B is also correct. The stomach, colon, and small intestines have muscularis mucosae.
92. ANSWER: D Because the mucous glands in the esophagus are submucosal in location. 93. ANSWER: C Letter A is correct, The acidophilia is This slide demonstrates due to a large volume of lysosome containing acid phosphatases. Letter B is correct. The osteoclasts are capable of mitosis but the osteoblasts are not. Letter D is correct. The typical distinguishing characteristics of an osteoclast: a large cell with multiple nuclei and a "foamy" cytosol.ANSWER: D 94. ANSWER: D 95. ANSWER: B The pancreas forms from the embryonic foregut and is therefore of endodermal origin. Pancreatic development begins with the formation of a ventral and dorsal buds (not midline). Each structure communicates with the foregut through a duct. The ventral pancreatic bud becomes the head and uncinate process, and comes from the hepatic diverticulum. 96. ANSWER: D The lateral longitudinal arch is composed of the calcaneus, the cuboid, and the fourth and fifth metatarsals.
97. ANSWER: D The deep external pudendal artery instead will supply the integument of the scrotum and perineum in the male, and the labia majora in the female. Its branches anastomose with the scrotal (or labial) branches of the perineal artery. 98. ANSWER: D Maxillary sinus is also known as antrum of Highmore. Infection here is quite common due to its closeness with the frontal sinus, maxillary teeth and anterior ethmoidal air sinus. Maxillary sinusitis is a form of paranasal infection that spreads rapidly, if not treated early. 99. ANSWER: D The palatoglossus is the only muscle of the tongue that is not innervated by the hypoglossal nerve (CN XII). It is innervated by the Vagus nerve (CN X). But some sources state that the palatoglossus is innervated by fibres from the cranial part of the accessory nerve (CN XI) that travel via the pharyngeal plexus. 100. ANSWER: C The atlanto-axial joint is between the first two vertabrae and allows LATERAL motion of the head. This is why the atlanto-axial joint is called the joint of "no" or "negative expression" because that is the motion it allows the head to make.
