By D. Mirzo. Case Western Reserve University.
Digestive System © The McGraw−Hill Anatomy cheap serophene 100 mg visa, Sixth Edition Body Companies, 2001 660 Unit 6 Maintenance of the Body Visceral peritoneum Spinal cord Vertebra Parietal peritoneum Plane of section Right kidney Left kidney Rib Spleen Waldrop Small intestine Liver Large intestine Inferior vena cava Stomach Peritoneal cavity Gallbladder Aorta Pancreas FIGURE 18. Constipation occurs when fecal material accumulates because Objective 17 Describe the location, structure, and functions of longer than normal periods between defecations. The slower rate of elimination allows more time for water absorption, so of the liver. Although uncomfortable and sometimes painful, this condition is usually not serious. Diarrhea oc- Objective 18 Describe the location of the gallbladder and curs when waste material passes too quickly through the colon, so trace the flow of bile through the systems of ducts into the that insufficient time is allowed for water absorption. Objective 19 Describe the location, structure, and functions of the pancreas. Identify the four principal regions of the large intestine and Three accessory digestive organs in the abdominal cavity aid in describe the functions of the colon. Describe the haustra and the taeniae coli and explain their in this process because their secretions are transported to the role in the movements of the large intestine. Describe the location of the rectum, anal canal, and anal sphincter muscles and explain how defecation is accomplished. Liver The liver is the largest internal organ of the body, weighing about 1. It is positioned immediately be- LIVER, GALLBLADDER, neath the diaphragm in the epigastric and right hypochondriac regions (see fig. The liver, consisting of four lobes, processes nutrients and se- The liver has four lobes and two supporting ligaments. An- cretes bile, which is stored and concentrated in the gallbladder teriorly, the right lobe is separated from the smaller left lobe by prior to discharge into the duodenum. Inferiorly, the caudate endocrine (islet) cells and exocrine (acini) cells, secretes impor- tant hormones into the blood and essential digestive enzymes into the duodenum. Digestive System © The McGraw−Hill Anatomy, Sixth Edition Body Companies, 2001 Chapter 18 Digestive System 661 Gallbladder Quadrate lobe Inferior vena cava Right lobe Coronary ligament Ligamentum teres Left lobe Cystic duct Hepatic duct Hepatic Right lobe artery Left lobe Hepatic portal Falciform Ligamentum teres vein ligament Caudate lobe Inferior vena cava Common bile duct Gallbladder Quadrate lobe Falciform ligament Hepatic artery Left lobe Right lobe Common bile duct Left triangular ligament Inferior vena Hepatic portal Ligamentum cava vein Caudate lobe venosum (c) FIGURE 18. The falciform liga- tercellular gaps between adjacent Kupffer cells make these sinu- ment attaches the liver to the anterior abdominal wall and the soids more highly permeable than other capillaries.
Osteochondral injuries of the femoral condyles displacement of the medial fragment cheap 25mg serophene with visa. Avulsion fractures at process of the calcaneus occur and must be distinguished the insertion of the posterior cruciate ligament are often from normal variants in this location. Knowledge of the in- missed on conventional imaging and diagnosis often fol- sertion point of the posterior cruciate ligament in this lo- lows MRI performed for persistent ankle pain. This fracture, which can be usually readily demonstrable on tangential views of the demonstrated on conventional imaging, has an extremely calcaneus or on CT. When this fracture is identified, MRI will clearly the calcaneus and navicular. In adolescent athletes, epiphyseal separations are cult to see on conventional imaging and may require CT more common than ligamentous injuries. Asymmetry in the width of the growth plate or small fracture fragments on The Forefoot the metaphyseal side of the growth plate should be suffi- cient to establish the diagnosis in most cases. MR may be The Lisfranc fracture-dislocation of the tarso-metatarsal a valuable technique when the nature of the injury is in joints is a frequent injury. This injury is easily over- question and also allows evaluation of ligamentous struc- looked, and a careful examination of the relationships of tures about the knee. Ankle and Hindfoot In the forefoot, stress and other fractures of the metatarsals are not uncommon. Avulsions of the base of Conventional imaging of the ankle should include AP, in- the fifth metatarsal, at the point of insertion of the per- ternal oblique (“mortise”) and lateral images. Fractures oneus brevis muscle, should be distinguished from of the malleoli are common ,and careful examination for “dancer’s fracture” or Jones fracture. These occur near the presence of posterior malleolar fracture is necessary the base of the fifth metatarsal, approximately 2. If a tal to the base, in a relatively avascular area of the shift of the talus in the ankle mortise has occurred and no metatarsal and may go on to non-union. Fractures of the lateral malleolar fracture is demonstrated, examination of phalanges in the foot are quite common. It is important the entire length of the fibula is necessary to demonstrate to evaluate all images so that these are not overlooked.
Hemoglobin is the red-pigmented The immune system is a complex organ- protein contained within the erythrocytes ization of specialized cells and organs that and is the speciﬁc part of the red blood cell distinguishes between self and nonself generic serophene 25mg on-line, that carries oxygen. Although the body is exposed to Special cells in the bone marrow pro- a number of microorganisms each day, the duce erythrocytes. Several vitamins, such immune system helps it ﬁght off bacteria, as vitamin B12 and folic acid (which is part viruses, and other microbes. Although of the vitamin B complex), are necessary constantly bombarded by microorganisms for the formation of erythrocytes. They are or trauma that can result in infection, dis- obtained from the diet. Iron, which is also ease, or injury, the body has speciﬁc de- obtained from the diet, is important for fenses to protect it against such invasions. Excess The immune system has traditionally amounts of iron and vitamin B12 are been divided into innate and adaptive com- stored in the liver. Although most erythrocytes are body’s ﬁrst line of defense against foreign released into the blood, some are taken up material is called nonspeciﬁc or innate im- by the spleen to be stored for emergency munity. This type of immunity includes the use when the red blood cell count drops protection provided by the skin, which signiﬁcantly below normal levels, such as acts as a barrier to organisms, and by the during hemorrhage. Newly formed red mucous membranes, gastric secretions, blood cells enter the bloodstream before and tears, which contain special chemicals they are totally mature. At this stage, they that destroy potentially harmful organ- are called reticulocytes. Innate immunity requires no previ- days, the cells mature to become erythro- ous exposure to the foreign substance or cytes. The life cycle of erythrocytes is recognition of any speciﬁc properties of approximately 120 days. When, despite exter- cytes reach the end of their life cycle, they nal and chemical barriers, an organism or become more fragile and rupture. Some of other foreign material gains entry into the the old erythrocytes are destroyed in the body, an inﬂammatory response results (the spleen. The main purpose of liver absorb the old erythrocytes, making the inﬂammatory response is to bring room for more new cells.