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Digestion/Resp/Lymph
The Digestive System
Question | Answer |
---|---|
What are the digestive organs of the alimentary canal? | Mouth,pharynx,esophagus,stomach,small and large intestine |
What are the accessory digestive system organs? | teeth, tongue, salivary glands, liver, gallbladder, and pancreas. |
What is the first function of the digestive system? | The digestive system controls the environment within it lumen to ensure optimal conditions for digestion and absorption of foodstuffs. |
What is the second function of the digestive system? | Receptors and hormone secreting cells in the alimentary canal wall respond to stretch and chemicals signals that result in stimulation or inhibition of GI secretory activity or motility. The alimentary canal has an intrinsic nerve supply. |
What are the major processes occurring during digestive system activity? | 1. Ingestion, 2. Movement of food through the tract, 3. Mechanical Digestion, 4. Chemical Digestion, 5. Absorption, 6. Elimination |
What is Ingestion? | food intake via the mouth |
What is mechanical digestion? | Processes that physically mix or break down food into smaller fragments. Includes chewing, mixing of food with saliva by the tongue, churning food in the stomach, and segmentation, or rhythmic local constrictions of the small intestine. |
What is chemical digestion? | Food breakdown by enzymatic action. Begins in the mouth and is essentially complete in the small intestine. |
What is Absorption? | transport of products of digestion through the intestinal mucosa into the blood. Occurs by active or passive transport into the blood or lymph. |
What is Elimination or Defecation? | the undigested residues (feces) from the body. Via the anus |
What is Propulsion? | second step of digestion. moves food through the alimentary canal, includes swallowing, which is initiated voluntarily, and peristalsis, the major means of propulsion, involves alternate waves of contraction and relaxation of muscles in the organ walls. |
What is segmentation? | mixes food with digestive juices and increases the efficiency of absorption by repeatedly moving different parts of the food mass over the intestinal wall. |
What is the location and function of the peritoneum? | The peritoneum is in the abdominopelvic cavity. Contains the visceral peritoneum, which covers the external surfaces of most digestive organs. Parietal peritoneum lines the body wall. Between the two peritoneums is the peritoneal cavity. |
What is retroperitoneal and name the retroperitoneal organs? | It is the space in the abdominal cavity behind the peritoneum. Pancreas and part of the large intestine. SAD PUCKER: adrenal glands, aorta, duodenum, pancreas, uterus, colon,kidneys, esophagus, rectum. |
What is the Structure and function of a mesentery? | is a double layer of peritoneum, a sheet of two serous membranes fused back to back that extends to the digestive organs fromt the body wall. Provides routes for blood vessels, lymphatics, and nerves to reach digestive viscera;hold organs in places |
What is the location of a mesentery? | The mesentery is dorsal and attaches to the posterior abdominal wall, but there are ventral mesenteries. |
Define Splanchnic circulation | Includes those arteries that branch off the abdominal aorta to serve the digestive organs. The arterial supply-the hepatic, splenic, and left gastric branches of teh celiac trunk that server the spleen, liver, and stomach, and the mesenteric arter |
What is the importance of the hepatic portal system? | The hepatic portal circulation collects nutrient rich venous blood draining from the digestive viscera and delivers it to the liverThe liver collects the absorbed nutrients for metabolic processing or storage before releasing them back to the bloodstream |
Name the digestive organs that the arterial supply of the hepatic, splenic, and left gastric branches off the celiac trunk supply. | spleen, liver, and stomach, |
Name the digestive organs served by the arterial supply of the mesenteric arteries | small and large intestines. |
Describe the tissue composition of the alimentary canal | mucosa, submucosa, muscularis externa, and a serosa (or adventitia. Intrinsic nerve plexuses are found within the wall. |
Describe the structure and function of Mucosa tissue in the alimentary canal. | is a moist epithelial membrane that lines the alimentary canal lumen from mouth to anus. Its major function are: to secrete mucus, digestive enzymes and hormones; to absorb the end products of digestion into the blood; and to protect against infectious D |
Describe the structure and function of SubMucosa tissue in the alimentary canal. | External to mucosa. Is areolar connective tissue containing a rich supply of blood and lymphatic vessels, lymphoid follicles, and nerve fibers. Elastic fibers enable the stomach to regain its normal shape after temporarily storing a large meal. |
Describe the structure and function of Muscularis externa tissue in the alimentary canal. | Surrounds the submucosa. Responsible for segmentation and peristalsis. |
Describe the structure and function of Serosa tissue in the alimentary canal. | protective outermost layer of the intraperiotneal organs, is the visceral peritoneum. Formed of areolar connective tissues covered with a single layer of squamous epithelial cells.The moist membrane found in closed ventral body cavities. |
Lips (labia) | protect the opening of the chamber/mouth |
Lingual frenulum | secures the inferior midline of the tongue to the floor of the mouth |
labial frenulum | is a median fold that joins the internal aspect of each lip to the gums. |
tongue | composed of interlacing bundles of skeletal muscle fibers, and druing chewing, it grips the food an constantly repositions it between the teeth. Also mixed food with saliva forming a bolus. Also helps with speech. |
vestibule | the space between the lips and cheeks and the teeth |
soft palate | fibromuscular structure that is unsupported by bone |
hard palate | the anterior portion of the palate |
cheeks | form the lateral wall |
palate | roof of the oral cavity |
palatine tonsils | on each side of the mouth at its posteior end are masses of lymphoid tissue |
palatoglossal arch | anterior membrane in oral cavity. Anchors the soft palate to the tongue |
palatopharyngeal arches | posterior membrane of oral cavity. Anchors the soft palate to the tongue. |
nasopharynx | behind the nasal cacity. Subdivision of the pharynx |
uvula | fingerlike projection of the soft palate, extends inferior from its posterior margin. rises to prevent food from entering respiratory passageways. |
oropharynx | behhind the oral cavity, extending from the soft palate to the the epiglottis overlying the larnx |
laryngopharynx | extending from the epiglottis to the base of the larynx. |
Esophagus | extends from the pharynx through the diaphram to the gastroesphageal sphincter in the superior aspect of the stomach. Is the essential food passage way that conducts food to the stomach in a wave like peristaltic motion. No digestion or absorption. |
Gastroesophageal sphincter | slight thickening of the smooth muscle layer at the esophagus-stomach junction. Controls food passage into the stomach. |
Stomach | on the left side of the abdominal cavity. 4 regions. Cardiac, fundus, body, pyloric. Temporary storage region for food. Mechanical and chemical digestion occur here. Most digestion occurs in pyloric region. |
Fundus | dome shape portion of the stomach, superolateral to the cardiac region. |
body of stomach | midportion of the stomach, inferior to the fundus |
cardiac region | the area surrounding the cardiac orifice through which food enters the stomach from the esophagus |
pyloric region | funnel shapped. consisting of the superior most pyloric antrum, the more narrow pyloric canal, and the terminal pylorus. Plyorus is continuous with the duodenum through pyloric valve. |
rugae | longitudinal wrinke folds. allow the stomach, or other tissue, to expand when needed. When the stomach is not full, the rugae are folds in the tissue. However, as the stomach fills it expands by unfolding the rugae. Helps reduce pressure |
lesser omentum | extends from the liver to the lesser curvature of the stomach.Help secure the stomach to other digestive organs and the body wall. |
greater omentum | a saclike mesentery, extends from the greater curvature of the stomach, reflects downward over the abdominal contents to cover them in an apronlike fashion (SI) Then runs dorsally and superiorly, wrapping the spleen and transverse portion of LI. |
greater curvature | convex lateral surface of the stomach |
lesser curvature | concave medial surface of stomach |
Small intestine | about 20 ft long. Extends from the pyloric sphincter to the ileocecal valve. 3 subdivision duodenum, jejunum, illeum. Virtually all absorption occurs here. major digestive organ(digestion completed here) |
mesentery | the membrane, consisting of a double layer of peritoneum, that invests the intestines, attaching them to the posterior wall of the abdomen, maintaining them in position in the abdominal cavity, and supplying them with blood vessels, nerves, and lymphatics |
duodenum | extends from the pyloric sphincter for about 10 inches and curves around the head of teh pancreas. |
jejunum | about 8ft long extends from teh duodenum to the ileum. most of jejunum occupies the umbilical region of abdominal cavity. |
ileum | 12 ft in length, joins the large intestine at the ileocecal valve. |
plicae circularis or circular folds | are deep permanent folds of the mucosa and submucosa. Force chyme to spiral through the lumen, slowing its movement and allowing time for full nutrient absorption. Occurs in SI. Increase surface area and allow for stretching |
large intestines | 5 feet long and extends from the ileocecal valve to the anus. subdivisions:cecum,vermiform appendix, colon, rectum, anal canal. Function absorb most of the remaining water from indigestible food residues, store the residues temp, and then eliminate(feces) |
appendix | attached to large intestine(cecum) posteromedial surface. Contains masses of lymphoid tissue and as a part of MALT is plays an important role in body immunity. |
cecum | is the first part of the large intestine.sac like |
ascending colon | travels up the right side of the abdominal cavity to the level of the right kidney. |
transverse colon | travels across the abdominal cavity |
descending colon | decends down the left side of the posterior abdominal wall |
sigmoid colon | starts at the s-shaped portion of the colon. continued from descending colon. |
rectum | where the sigmoid colon ends. at the level of the third sacral vertebrae. Runs posteroinferioly just in from of the sacrum. |
anal canal | the last segment of the LI. lies in the perneum, entirely external to the abdominopelvic cavity.terminates at the anus. About 3cm long. |
haustra or haustrum | pocket like sacs in LI |
anus | opening to the exterior body. has two sphincters, internal and external. |
salivary glands | parotid glands, sublingual glands, and submandibular glands.Empty their secretions into the oral cavity. |
parotid glands | large glands located anterior to the ear and ducting into the mouth over the second upper molar through parotid duct. |
submandibular glands | located along the medial aspect of the mandibular body in the floor of the mouth, and ducting under the tongue to the base of the lingual frenulum |
sublingual glands | small glands located most anteriorly in the floor of the mouth and emptying under the tongue via several small ducts. |
gallbladder | thin walled green muscular sac about 4 inches long. It snuggles in a shallow fossa on teh ventral surface of the liver.Stores bile. Bile is expelled into its cystic duct and then flows into the bile duct. |
pancreas | is a soft tadpole shaped gland that extends across teh abdomen from its tail(abutting the spleen) to its head, which is encircled by the C-shaped duodenum. Lies deep to teh greater curvature. produces enzymes that break down food. Pancreatic juices to SI. |
pancreatic duct | fuses with the bile duct just as it enters the duodenum. Delievers pancreatic juice(very alkaline) from pancreas. Helps regulate PH for proper absoprtion in SI |
liver | largest gland in the body is located inferior the the diapharam, more to the right than the left side of teh body. Has four lobes. Main function is to filter and process the nutrient rich blood delievered to it.produce bile. |
common hepatic duct | from the liver it travels downward toward the duodenum. Then enter through the duodenum to where it fuses with the cystic duct to form the bile duct. Bile leaves the liver here. Bile emulsifies fat. |
cystic duct | drains the gallbladder and then forms the bile duct. Bile leaves through here |
sphincter of Oddi(hepatopancreatic sphincter) | is a muscular valve that controls the flow of digestive juices (bile and pancreatic juice) through the hepatopancreatic ampulla(union of pancreatic duct and bile duct)into the second part of the duodenum |
Nares | Nostrils. produces mucus;filters,warms,and moistens incoming air; resonance chamber for speech. |
nasal cavity | lies in and posterior to the external nose. Air enters the cavity by passing through the nostril or nares. Divided by a midline nasal septum. |
nasal septum | divides the nasal cavity. Septial cartilage |
paranasalsinuses | frontal, sphenoid, ethmoid, and maxillary. Mucosa lined, air filled cavities in cranial bones surrounding nasal cavity. produces mucus, filters, warms, and moistens incoming air. |
larynx | connects pharynx to trachea. Has framework of cartilage and dense connective tissue. Opening(glottis) can be closed by epiglotis. Airpassage way; prevents food from entering lower respirartory tract. |
pleurae | serous membranes. Parietal pluerae lines thoracic cavity;visceral pleura covers external lung surfaces. Produce lubricating fluid and compartmentalize lungs. |
lungs | paired, flank mediastinum in thorax.composed primarily of alveoli and respirtory passageways. Stroma is fibrous elastic connective tissue, allowing lungs to recoil passively during expiration. House respiratory passages smaller than the main bronchi. |
alveoli | microscopic chambers at termini of bronchial tree. Walls of simple squamous epithelium are underlain by thin basement membrane. Exteral surfaces coverey with pulmonary capillaries. Main gas exchange site. |
Bronchial Tree | Consists of right and left main bronchi, which subdivide within the lungs to form lobar, and segmental bronchi and bronchiles. Bronchiolar walls lack cartilage but contain SM. Connects tracha with alveoli. Cleans, warms, and moistens incoming air. |
Trachea | flexible tube running from larynx and dividing inferiorly into two main bronchi. Walls contain c shaped cartilages that are incomplete posteriorly where connected by tracheal muscle. Airpassageway; cleans warms, and moistens incoming air. |
pharynx | passage way connecting nasal cavity to larynx and oral cavity to esophagus. There subdivision: nasopharynx,oropharynx, and laryngopharynx. Passageway for food and air. |
epiglottis | spoon shaped, elastic cartilage located superior to the opening of the larynx. forms a lid over the larynx when we swallow. Prevent food from entering trachea. |
Thyroid cartilage | one of the nine cartilages of the larynx. Large shield shaped fused by two cartilage plates. Located at the midline laryngeal prominence which marks the fusion point. Larger in males and smaller in females |
cricoid cartilage | inferior to thyroid cartilage, p ring shaped, perched atop and anchored to the trachea inferiorly. |
true vocal cords or vocal folds | vocal folds of the larynx (plicae vocales). They are located inferior to the false vocal cords. The vocal folds vibrate, producing sounds as air rushes up from the lungs. |
false vocal cords or vestibular folds | hese are a pair of thick folds of mucous membrane that protect and sit slightly superior to the more delicate true folds. They play no direct part in sound production but help to close glottis when we swallow. |
laryngeal prominence | adams apple. made up of thyroid cartilage. Marks the fusion point of thyroid cartilage plates. |
glottis | The slit like opening between the vocal cords at the upper part of the larynx. |
hyoid bone | A U-shaped bone at the base of the tongue that supports the muscles of the tongue. The hyoid is anchored by muscles from the anterior, posterior and inferior directions, and aids in tongue movement and swallowing. |
alveolar ducts | respiratory bronchioles turn into alveolar ducts, which terminate in alveolar sacs. Ducts consist of diffusely arranged rings of smooth muscle cells, connective tissue fibers and out pocketing alveoli. |
respiratory bronchioles | terminal bronchioles feed into respiratory bronchioles within the lung. They lead into winding alveolar ducts. Protruding from these smallest bronchioles are scattered alveoli. Smoot muscle increases as they get smaller. |
bronchioles | little bronchi eventually becomes terminal bronchioles which lead into the respiratory bronchioles |
hilus or hilum | an indentation of each lung where pulmonary and systemic blood vessels, bronchi, lymphatic vessels and nerves enter and leave the lungs. |
Tidal Volume (TV) | 500ml. Amount of air inhaled or exhaled with each breath under resting conditions |
Inspiratory reserve volume (IRV) | Male Avg. 3100ml. Female 1900ml. Amount of air that can be forcefully inhaled after a normal tidal volume inhalation |
Expiratory Reserve volume (ERV) | 1200ml Male. 700ml Female. Amount of air that can be forcefully exhaled after a normal tidal volume exhalation |
Residual Volume (RV) | 1200ml male, 1100 female. Amount of air remaining in the lungs after a forced exhalation. |
Total lung capacity (TLC) | 6000ml male, 4200ml female. Maximum amount of air contained in lungs after a maximum inspiratory effort: TLC = TV +IRV +ERV +RV |
Vital capacity (VC) | 4800ml male, female 3100ml. Maximum amount of air that can be expired after a maximum inspiratory effort: VC= TV + IRV + ERV |
Inspiratory capacity (IC) | 3600ml male, 2400 ml female. Maximum amount of air that can be inspired after a normal expiration. IC = TV +IRV |
Functional residual capacity (FRC) | 2400ml male, 1800ml female. Volume of air remaining in the lungs after a normal tidal volume expiration. FRC =ERV +RV |
lymph nodes | principal lympoid organs in the body. Cluster along the lymphatic vessels of the body. Large clusters appear in the inguinal, axillary, and cervical regions. filter and process lymph and activate immune system. |
cortex | contains densely packed follicles, many with germinal centers heavy with dividing B cells. T cells contained in the deeper part of the cortex. |
Medulla | central portion of lymph node. contains medullary cords and medullary sinus. |
Medullary cords | medullary cords are cords of lymphatic tissue, and include plasma cells, macrophages, and B cells |
medullary sinuses | medullary sinuses (or sinusoids) are vessel-like spaces separating the medullary cords. Medullary sinuses contain macrophages on the reticular cells and kill foreign matter. |
afferent lymphatic vessel | vessel where lymph flows into the lymph node |
efferent lymphatic vessel | vessel where lymph flow out of the lymph node |
germinal center | contains heavy with dividing B cells |
Identify accessory organs to the lymphatic system | tonsils, spleen, peyer's patch |
identify primary lymphatic organs | bone marrow and thymus |
Give examples of Malt | mucuos associated lymphoid tissue. Peyers patch, appendix, tonsils |
emphysema | permanent enlargement and destruction of alveoli. Lungs lose their elasticity, and expiration becomes an active process. |
tuberculosis (TB) | an infectious disease caused by airborne bacterium, mainly affects the lungs. Depresses immunity function. inflammation in lungs. causes scarring which decrease elasticity, reducing lung compliance. small granulomas (tubercles in upper lobes form. |
anthracosis | coal miners lung. coal particles trapped in alveoli. |
Name 3 tonsil | pharyngeal, palatine, lingual |
parietal cells | found in middle region of the glands in the stomach. secrete HCL & Intrinsic Factor. Appear spherical when viewed. Fuzzy pitch forks. Intrinsic factor helps absorb b12. HCL makes it acidic to activate pepsinogen helps breakdown food. Huge surface area. |
chief cells | occur in basal regions of the gastric glands. Produce pesinogen. also secrete lipases. |