Worst Foods for Digestion
The flexibility allows long-beaked birds to open their mouths wide enough to hunt on the wing. The spongy bone is thought to evenly distribute mechanical vibrations before they propogate to the brain. World Journal of Gastroenterology. A Price Worth Paying -- Birds don't need teeth to grind their food; they solve the mashing problem with a powerful gizzard. These parts of the tract have a mesentery. ALP levels typically are greatly elevated in the young, growing animal and therefore a veterinarian should not mistake any elevations as disease in a young animal.
Ostrich Struthio camelus stomach. Note how particle size of material in the gizzard ventriculus is smaller than in the proventriculus due to the grinding action of the muscular walls plus small pebbles gastroliths. The capacity to reduce particle size is related to the metabolic demands of a species. Therefore, particle size reduction is often considered the key digestive difference between ecto- and endotherms that allows endotherms to rely on shorter digesta retention times without losing digestive efficiency, and hence facilitate the high level of food intake necessary to meet their increased metabolic requirements.
In contrast, adaptations for chewing intrinsically increase the weight of the head. The use of the gizzard system has the potential advantages that intake rate is not limited by chewing, that no investment in dental tissue is necessary, and that dental wear is not a determinant of senescence as observed in mammals.
The absence of age-dependent tooth wear might even be a contributing factor to the slower onset of senescence in birds as compared to mammals. On the other hand, the use of a gizzard requires the intake of suitable grit or stones—an action that represents, in the few studies where this has actually been quantified in birds, a relevant proportion of feeding time Fritz et al.
Gastrointestinal tracts of a carnivorous hawk, an omnivorous chicken, and 4 herbivorous birds. Note larger size of crop in omnivore and herbivores, and particularly in hoatzin. Ceca are small in hawks and relatively large in grouse. Although ceca are relatively small in Hoatzins , Emus, and Ostriches, an expanded foregut Hoatzins , a much longer midgut Emus , or a much longer colon Ostriches compensates for this From: Stevens and Hume Over-reliance on the passive pathway provides metabolic advantages and ecological constraints.
It does provide birds with an absorptive process that can deal with rapid and large changes in intestinal sugar concentrations.
The passive pathway is also energetically inexpensive to maintain and modulate. However, passive absorption through the paracellular pathway is dependent on concentration gradients. In the absence of a transport system that selects which materials to absorb, this non-discriminatory pathway may also increase vulnerability to toxins, and thus constrain foraging behavior and limit the breadth of the dietary niche of the birds.
Another problem is that when luminal sugar concentrations are lower than those in plasma, glucose may diffuse back into the lumen. Cross-section of the intestine ileum of a Spotted Tinamou Nothura maculosa. Villi are lined with columnar epithelium EP , including goblet cells arrows that secrete mucus. The muscle layer includes longitudinal fibers MI on the perimeter, circular fibers Mc , and additional longitudinal fibers at the base of the villi muscularis muscosae; MM From: Chikilian and de Speroni Blue-headed Parrots at clay lick.
Meyer-Rochow and Gal determined that the pressures involved could be approximated if they knew the 1 distance the feces traveled, 2 density and viscosity of the material, and 3 shape, aperture, and height of the anus above ground. How penguins choose the direction of defecation, and how wind direction factors into that decision, remain unknown. Avian Pancreas tissue Source: The Avian Digestive Tract. Avian geophagy and soil characteristics in southeastern Peru. Luminal morphology of the avian lower intestine: Histological aspects of the stomach proventriculus and gizzard of the Red-capped Cardinal Paroaria gularis gularis.
Comparative study of the digestive system of three species of tinamou. Crypturellus tataupa, Nothoprocta cinerascens , and Nothura maculosa Aves: Journal of Morphology Journal of Experimental Zoology Rictal bristle function in Willow Flycatcher. Dysplastic koilin causing proventricular obstruction in an Eclectus Parrot Eclectus roratus.
Journal of Avian Medicine and Surgery Anatomy and physiology of the digestive system in fowl. Pages in Proc. An histological and histochemical analysis of the inner lining and glandular epithelium of the chicken gizzard.
American Journal of Anatomy An ecomorphological study of the raptorial digital tendon locking mechanism. Dietary and developmental regulation of intestinal sugar transport. Digesta retention patterns in geese Anser anser and turkeys Meleagris gallopavo and deduced function of avian caeca.
Comparative Biochemistry and Physiology A Histological and global gene expression analysis of the 'lactating' pigeon crop. Vultures of the seas: Evolution of the structure and function of the vertebrate tongue. Journal of Anatomy Light and scanning electron microscopic study of the tongue in the cormorant Phalacrocorax carbo Phalacrocoracidae, Aves. Functional morphology of the tongue in the nutcracker Nucifraga caryocatactes.
A tropical horde of counterfeit predator eyes. Instructed learning in the auditory localization pathway of the Barn Owl. The morphology of the bill apparatus in the Steller's Sea Eagle. Wild Bird Society of Japan, Tokyo. Use of dung as a tool by burrowing owls. The integration of energy and nitrogen balance in the hummingbird Sephanoides sephaniodes. Does gut function limit hummingbird food intake?
Physiological and Biochemical Zoology Pressures produced when penguins pooh—calculations on avian defaecation. Scare tactics in a neotropical warbler: Gliding flight and soaring. Theoretical Ecology Series, vol. Modelling the flying bird C. Structure, form, and function of flight in engineering and the living world. Phenotypic flexibility and the evolution of organismal design.
Trends in Ecology and Evolution The hummingbird tongue is a fluid trap, not a capillary tube. Between air and water: Use of prey hotspots by an avian predator: Structure and mechanical behavior of a toucan beak. Movement and direction of movement of a simulated prey affect the success rate in Barn Owl Tyto alba attack. Musculoskeletal underpinnings to differences in killing behavior between North American accipiters Falconiformes: Accipitridae and falcons Falconidae.
Journal of Morphology, online early. Le Bohec, and Y. Adjustments of gastric pH, motility and temperature during long-term preservation of stomach contents in free-ranging incubating King Penguins. Journal of Experimental Biology A tough nut to crack. Adaptations to seed cracking in finches. Cost-benefit analysis of mollusc-eating in a shorebird.
Optimizing gizzard size in the face of seasonal demands. How do woodpeckers extract grubs with their tongues? Why do woodpeckers resist head impact injury: Functional morphology of raptor hindlimbs: The turning- and linear-maneuvering performance of birds: Canadian Journal of Zoology Hummingbird jaw bends to aid insect capture.
A mechanical analysis of woodpecker drumming and its application to shock-absorbing systems. I - Introduction to Birds. VII - Circulatory System.
Back to Avian Biology. Drawings of the digestive tracts of A a Greylag Goose and B a Wild Turkey and retention times of a solute, 2-mm particles, and 8-mm particles in the goose and turkey digestive systems Figure from Frei et al.
The closed, air-filled spaces reduce overall weight without loss of rigidity. The capillary ratchet mechanism Surface tension transport of prey by feeding shorebirds: The serrated leading-edge feather of an owl Norberg Vortex generators on an airplane wing. Fish-eating species like cormorants below - typically have small, undifferentiated tongue because fish are often swallowed whole. Representative caterpillar false eyes and faces. In some, like woodpeckers, the 'sticky' saliva aids in capturing prey.
In others, like swifts, saliva is used in nest building see photo below. The muscular walls of the esophagus produce wave-like contractions peristalsis that help propel food from the oral cavity to the stomach. Anhinga swallowing a large fish. HCL and pepsinogen are secreted by the deep glands see photomicrograph below.
Pepsinogen is converted into pepsin a proteolytic, or protein-digesting, enzyme by the HCl. The cuticle is secreted by simple tubular glands see photomicrograph below. Grinding action may, particularly in seed-eating birds, be assisted by grit and stones deliberately ingested.
The avian gastrointestinal tract, unlike that of mammals, executes distinct reverse peristaltic movements that are critical to optimal digestive function Duke The gastric reflux allows material in the gizzard to reenter the proventriculus for additional treatment with acid and pepsin. Villi are projections from the intestinal wall that increase the amount of surface area available for absorption.
Further increasing the surface area are the numerous microvilli of the cells lining the surface of the villi. Inside each villus are blood vessels that absorb nutrients for transport throughout the body.
Caeca are histologically similar to the small and large intestines and found in a wide variety of birds. In these large ceca, food particles are acted upon by cecal secretions, bacteria, and fungi and nutrients can be absorbed. Lymphoid ceca are not important in digestion but contain lymphocytes white blood cells that produce antibodies Clench At various times and under various conditions, ceca are the site for 1 fermentation and further digestion of food especially for the breakdown of cellulose and absorption of nutrients, 2 production of antibodies, and 3 the use and absorption of water and nitrogenous components Clench The bursa is most prominent in young birds and serves as the area where B-lymphocytes the white blood cells that produce antibodies are generated T-lymphocytes are generated in the Thymus.
Bile emulsifies fats or, in other words, breaks fats down into tiny particles. Emulsification is important because it physically breaks down fats into particles than can then be more easily digested by enzymes lipase produced by intestinal cells and the pancreas. This 'juice' contains a bicarbonate solution that helps neutralize the acids coming into the intestine from the stomach plus a variety of digestive enzymes.
The enzymes help break down fats, proteins, and carbohydrates. The pancreas also produces the hormones insulin and glucagon which regulate blood sugar levels cells that produce these two hormones make up the 'islets of Langerhans', one of which is represented by the light-colored, circular structure in the photomicrograph below.
Hit 'Reload' or 'Refresh' to View Again! Particle retention time hr. Flamingos use a series of projections, or lamellae, to filter tiny food items from debris in the water. Wrens use their thin, probing bill to capture small insects. Curlews use their long bill to probe mudflats for small invertebrates. Finches do not simply bite the seeds; instead; the lower mandible is moved toward the tip of the bill in a slicing motion.
When most of the coat has been cracked or removed, the lower mandible is moved from side to side to remove the rest of the shell, thus releasing the kernel. Some large finches also have raised hard surfaces in the upper palate that function as anvils so large seeds can be held firmly while the lower mandible slices and cracks the sides of the seed.
As tricky as nutcracking sounds, most birds accomplish it rapidly, shelling small seeds in a few seconds and large finches can crack open and devour a large seed or nut in less than twenty seconds.
Big mouths get hummingbirds an in-flight meal - Hummingbirds have bendy lower beaks to help them catch insects Yanega and Rubega The flexibility allows long-beaked birds to open their mouths wide enough to hunt on the wing. Hummingbirds use their long, narrow beaks to probe flowers for nectar, but they also need insects for essential nutrients.
It wasn't clear how they could catch them; birds that hunt flying insects usually have short beaks to help them open their mouths wide. The endoscopy allows the physician to check the lining of the esophagus and stomach for inflammation and obtain a tissue sample if needed, which would help to determine the underlying cause of burning sensation in stomach. Gastroesophageal Reflux Disease GERD - Gastroesophageal reflux occurs when the lower esophageal sphincter opens inappropriately or fails to close completely.
When reflux occurs, digestive acids rise up into the esophagus, causing the common burning sensation known as heartburn. To rule out GERD, a physician may need to perform additional tests on patients who report symptoms of heartburn that worsen at night or when lying down. Medications or drugs - Medications like aspirin and Tylenol and excessive alcohol use and smoking can increase stomach pain and irritation. In addition, anti-inflammatory drugs like Ibuprofen and Naproxen can break down the protective lining of the stomach, putting the individual at risk for gastritis.
Stress can slow down the digestion of food to where the stomach acids remain in the stomach, increasing the chance that reflux will occur. A physician can diagnose emotional stress with a detailed health interview or mental health examination to determine whether stress is the underlying cause of the burning stomach pain. The treatment is based on the patient's medical history and current symptoms. Blood test, endoscopies, upper gastrointestinal x-rays, and other procedures help rule out serious underlying medical diseases.
Swift treatment of the symptoms can help to prevent potential long-term medical complications. Having nausea after eating? It indicates your intestines or digestive system is suffering. Why does this happen? And how can you get some relief? Last Updated 16 September, Just before the main pancreatic duct enters the duodenum, it usually merges with the common bile duct that collects bile a fluid that helps to digest fat produced by the liver. The common bile duct usually joins the pancreatic duct in the head of the pancreas.
The union of these two ducts forms the ampulla of Vater which drains both the bile and pancreatic fluid into the duodenum through the papilla of Vater. Buried within the tissue of the pancreas, primarily in the head, are small collections of cells, termed the Islets of Langerhans. The cells of the Islets produce several hormones, for example, insulin , glucagon, and somatostatin; that are released into the blood the islets do not connect with the pancreatic ducts and travel in the blood to other parts of the body.
These hormones have effects throughout the body, for example, insulin, which helps to regulate blood sugar levels. The hormone-secreting portion of the pancreas - the Islets - is the endocrine part of the pancreas. What are pancreatic cysts? Pancreatic cysts are collections pools of fluid that can form within the head, body, and tail of the pancreas. Some pancreatic cysts are true cysts non-inflammatory cysts , that is, they are lined by a special layer of cells that are responsible for secreting fluid into the cysts.
Other cysts are pseudocysts inflammatory cysts and do not contain specialized lining cells. Often these pseudocysts contain pancreatic digestive juices because they are connected to the pancreatic ducts.
Pancreatic cysts can range in size from several millimeters to several centimeters. Many pancreatic cysts are small and benign and produce no symptoms, but some cysts become large and cause symptoms, and others are cancerous or precancerous. Precancerous cysts are benign cysts that have the potential to become cancerous.
Different types of cysts contain different types of fluids. For example, pseudocysts that form after an attack of acute pancreatitis contain digestive enzymes, such as amylase, in high concentrations. Mucinous cysts contain mucus a proteinaceous liquid produced by the mucinous cells that form the inside lining of the cyst.
What are the symptoms of pancreatic cysts? What are the causes of pancreatic cysts? There are two major types of pancreatic cysts; pseudocysts inflammatory cysts and true cysts non-inflammatory cysts.
Inflammatory cysts are benign, whereas non-inflammatory cysts can be benign, precancerous, or cancerous. Most of the inflammatory cysts of the pancreas are pancreatic pseudocysts.
Pseudocysts of the pancreas result from pancreatitis inflammation of the pancreas. The common causes of pancreatitis include alcoholism , gallstones , trauma , and surgery. The fluid inside the pseudocysts represents liquefied dead pancreatic tissue, cells of inflammation, and a high concentration of digestive enzymes that are present in pancreatic exocrine secretions.
Most pseudocysts have connections with the pancreatic ducts. Most pseudocysts caused by acute pancreatitis resolve spontaneously without treatment within several weeks.
Pseudocysts that need treatment are those that persist beyond six weeks and are causing symptoms such as pain, obstruction of the stomach or duodenum, or have become infected. How are pancreatic cysts diagnosed? Since the majority of pancreatic cysts are small and produce no symptoms, they often are discovered incidentally when abdominal scans ultrasound [US], computerized tomography or CT, magnetic resonance imaging or MRI are performed to investigate unrelated symptoms.
Unfortunately, ultrasound, CT, and MRI cannot reliably distinguish benign cysts cysts that usually need no treatment from precancerous and cancerous cysts cysts that usually require surgical removal. Endoscopic ultrasound EUS is becoming increasingly useful in determining whether a pancreatic cyst is likely to be benign, precancerous, or cancerous. From this location, which is very close to the pancreas, liver, and gallbladder, accurate and detailed images can be obtained of the liver, pancreas and the gallbladder.
During endoscopic ultrasound, fluid from cysts and samples of tissue also can be obtained by passing special needles through the endoscope and into the cysts. The process of obtaining tissue or fluid with a thin needle is called fine needle aspiration FNA.
The fluid obtained by FNA can be analyzed for cancerous cells cytology , amylase content, and for tumor markers. Tumor markers, such as CEA carcinoembryonic antigen , are proteins produced in large quantities by cancer cells.
For example, pancreatic pseudocyst fluid will typically have high amylase levels but low CEA levels. A benign serous cyst adenoma will have low amylase and low CEA levels, whereas a precancerous or cancerous mucinous cyst adenoma will have low amylase levels but high CEA levels. Most recently, DNA from cells that are aspirated from the cyst has been analyzed for changes suggestive of cancer.
The risks of endoscopic ultrasound and fine needle aspiration are small and consist of a very small incidence of bleeding and infection. Occasionally, it is difficult even with the diagnostic tools of endoscopic ultrasound and fine needle aspiration to determine if a pancreatic cyst is cancerous or precancerous.
If the answer is not clear, sometimes repeated endoscopic ultrasound and aspiration are done if the suspicion for cancer or precancer is high. In other cases, the cyst is reexamined by CT, MRI, or even endoscopic ultrasound after a few months to detect changes that more strongly suggest that cancer has developed. In still others, surgery is recommended. What is the treatment for pancreatic cysts? The most important aspect of management of pancreatic cysts is the determination of whether a cyst is benign and usually needs no treatment or if it is precancerous or cancerous and must be removed.