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Nutrition Ch.3
Ch.3 The Human Body
Question | Answer |
---|---|
If you eat only small amouts of food, over time, your stomach will permanently shrink? True or False | False- near starvation doesn't cause the stomach to shrink permanently. Like wise the stomach doesn't stretch permanently, Only after gastric surgery, when a small stomach pouch remains, can the stomach tissue stretch permanently |
The entire process of the digestion and absorbtion of one meal takes about 24 hours? True of False | True |
Most ulcers result from a type of infection? | True- usually result from an infection of the bacterium Helicobacter pylori (H, pylori). Contrary to popular belief ulcers are not caused by stress or spicey food |
Which of the following represents the levels of organization in the human body from smallest to largest? | atoms, molecules, cells, tissues, organs and systems |
The cell membrane is composed of? | two flexible layers of phospholipid molecules |
The region of brain tissue that is responsible for prompting us to seek food is the? | hypothalamus |
Most digestion of carbs, fats and proteins takes place in the? | Middle segment of the small inestine |
The nerves of the GI track are? | collectively known as the enteric nervous system |
Heartburn is caused by pooling of | Gastric juices in the esophagus |
Food encounters the pharynx before it encounters the esophagus? True or False | True |
Bile is produced by the gallbladder? True or False | False |
Diarrhea can be a normal, protective response to infection? True or False | True |
What is a molecule of water composed of? | 2 atoms of hydrogen and 1 atom of water |
Cells are | the smallest units of life. take in nutrients, produce chemicals and excrete wastes |
Enterocytes are? (entero- prefix referring to the intestine and -cyte means cell) | The cells lining the wall of the intestine. |
Tissues are? | A grouping of like calls that performs a function; for example, muscle tissue |
Organ is? | A body structure composed of two or more tissues and performing a specific function; for example, the esophagus |
System is? | A group of prgans that work together to perform a unique function; for example, the gastrointestinal system |
Cell membrane is? (double layer of phospholipid molecules) | The boundary of an animal cell that separates its internal cytoplasm and organelles from the external environment. Acts as a gatekeeper allowing/deying the entry/exit of molecules, such as nutrients and wastes |
The fluid inside the cell is semiliquid called? | cytoplasm |
Most important organelles are? | Nucleus, Ribosomes, Endoplasmic Reticulum (ER), Mitochondira |
Nucleus is? | Where DNA is located |
Ribosomes do? | Use the instructions from DNA to assemble proteins |
Endoplasmic reticulum (ER)does what? | Synthesis of lipids and many other cell functions. Proteins assembled on the ribosomes enter this network of channels and are further processed and packaged for transport |
Mitochondria is? (aka power house) | Produces ATP (adenosine triphosphate). cells with high energy needs like muscle cells have more mitochondria |
Organelle is? | A tiny "organ" within a cell that performs a discrete function necessary to the cell |
Hunger is? | A physiologic drive for food |
Anorexia is? | An absence of appetitie |
Hypothalamus is? | A region of the forebrain above the pituitary gland, where visceral sensations, such as hunger and thirst, are regulated, prompting us to seek food |
Appetite is? | A desire to eat that is stimulated by the sight, smell or thought of food |
Satiety means? | A physiologic sensation of fullness- signal s froma cluster of cells called satiety center |
3 sources feeding and satiety centers integrate signals | 1) Nerve cells in the gastro system 2) Chemicals called hormones 3) amount/type of food we eat |
Hormones are? | A chemical messenger secreted into the bloodstream by a gland. Sends chemical messages to the hypothalamus |
Insulin and Glucagon are two hormones responsible for? | Maintaining blood glucose levels |
Decrease in the level of insulin and increase level in glucagon prompts us to? | Prompts us to eat in order to supply our body with more glucose |
When an increase in insulin and decrease in glucagon happens we experience? | satiety |
Digestion is? | The process by which foods are broken down into their component molecules, either mechanically or chemically |
Absorption is? | process of taking these products of digestion through the wall of the small intestine into the circulation |
Elimination is? | Process by which the remaining waste is removed from the body |
Organs of the GI Tract | Mouth, Pharynx/esophagus, Stomach, Sm. Intestine, Lg. Intestine, and Rectum |
Accessory Organs of the GI tract | Salivary Glands, Liver, Gallbladder, and Pancreas |
Pancreas does what in digestion? | Produces digestive enzymes and bicarbonate which are released into the small testine via the pancreatic duct |
Large intestine does what in digestion? | Absorption: Reabsorbs salts, water and vitamins Propulsion: Compacts waste into feces and propels in toward the rectum |
Small intestine does what in digestion? | Absorption: Nutrients are absorbed into blood and lymph through enterocytes |
Stomach does what in digestion? | Chemical digestion: Pepsin begins digestion of proteins, and gastric lipase begins to break lipids apart |
Pharynx and Esophagus does what in digestion? | Propulsion: Swallowing and peristalsis move food from mouth to stomach |
The processing of food in the GI tract involves? | ingestion, mechanical digestion, chemical digestion, propulsion, absorption, and elimination |
Sphincter is? | A tight ring of muscle separating some of the organs of the GI tract and opening in response to nerve signals indicating that food is ready to pass into the next section |
Salivary amylase begins chemical breakdown of? | Carbohydrates |
Appetite is triggered by? | Environmental cues, such as the smell or taste of food |
Our genetic info in the form of DNA is located in the? | Nucleus |
Where in the body does majority of the digestion and absorption of food occur? | small intestine |
Which organ is responsible for manufacturing/secreting digestive enzymes and bicarbs | pancreas |
After you eat a burger w/fries, choc. milk, the fat in the meal? | is emulsified by bile |