Flashcards
Anatomy - Digestive System
Cards in this deck (53)
- 1Describe what digestive system is formed from (2)1. Gastrointestinal tract (tube from mouth to anus)
2. Accessory Organs (teeth, tongue, salivary glands, pancreas, liver, gallbladder) - 2Functions of Digestive Tract1. Ingestion
2. Digestion
a. Mechanical: chewing, churning, segmentation of food, peristalsis
b. Chemical: enzymes and secretions of acid break down
3. Absorption (end products taken into blood&lymph)
4. Defecation - 3Visceral Smooth Muscle- composed of thick&thin myofilaments
- no striations/myofibrils/sacromeres
- cells are spindle shaped
- one centrally located nucleus
- found in sheets --> operates as a unit called SYNCYTIUM
- interconnected by gap junctions - 4Peritoneum- serous membrane:
visceral (serosa): organ wall, parietal: lines walls of cavity
- cavity filled with serous fluid - 5Mesentery- double layer of peritoneum (fused)
- extends to organs from wall of cavity
- Functions:
a. Provides a route for vessels(b&l)&nerves to reach viscera of organs
b. holds organs in place
c. lipid storage
- binds small/large intestines to cavity wall - 6Greater Omentumspecific term for mesentery that covers transverse colon and the small intestine
Provides: protection, source of stored energy, insulation - 7Lesser Omentumspecific term for mesentery that suspends stomach from the liver
- 8Peritonitisinflammation of peritoneum (very serious)
- 9Retroperitoneal Organs- located posterior to peritoneum
Parietal peritoneum: anterior surface of organ
Adventitia (CT): posterior surface of organ
ex. pancreas & duodenum - 10Histology of Digestive tract: 4 layers1. Serosa/ Adventitia
2. Muscularis Externa
3. Submucosa
4. Mucosa - 11Serosa/ Adventitia- adventitia in esophagus
- fibrous CT/no epithelium
- outermost protective layer of organs located in PERITONEAL cavity
- Retroperitoneal organs contain serosa&adventitia - 12Muscularis Externa- layer of visceral smooth muscle
- contractions: mobility (peristalsis)
- inner circular layer -> myenteric nerve plexus -> outer longtitudina layer - 13Submucosa- areolar CT
- Function: bind mucosa muscularis externa
- contains lymph and blood vessels
- submucosal nerve plexus - 14Mucosa- innermost layer of digestive tract
- mucous membrane (faces lumen)
- has 3 layers - 15Layers of Mucosa: 1. Muscularis Mucosa- located next to submucosa
- composed of smooth muscle
- allows mucosal movement - 16Layers of Mucosa: 2. Lamina Propria- areolar CT
- located centre of mucosal layer
- contains blood, lymphatic vessels & tissues - 17Layers of Mucosa: 3. The Mucosal EpitheliumStratified squamous epi: mouth, pharynx, esophagus, anal canal
simple columnar epi: stomach, small&large intestine
- layer contains Goblet cells - 18The Mouth: Oral CavityOral Cavity: lips, cheeks, palate, tongue
- lined by MUCOSA & SKELETAL muscle
Mouth: tongue, palate, salivary glands, teeth - 19Tongue- composed of skeletal muscle
- mucosa on surface
- superior surface: projections of mucosa (papillae): 3 types, some have tastebuds
- dorsal surface: lingual glands: contain fluid & lingual lipase (enzyme for fat digestion) - 20PalateHard: anterior (formed from maxillae & palatine)
Soft: posterior (formed from uvula & skeletal muscle arch - 21Salivary Glands: 1. Parotid Gland- located inferior & anterior to ears
- thin saliva:
lacks MUCUS, rich in SALIVARY AMYLASE - 22Salivary Glands: 2. Submandibular Gland- located bottom of mouth
- fluid mixture (mucus&amylase) - 23Salivary Glands: 3. Sublingual Gland- below the tongue
- produces only mucus - 24Salivary Glands: Saliva- 99.5% water
- 0.5% dissolved solutes (lysozyme, amylase) - 25Mumps?results from inflammation of parotid glands (1 or both)
- 26Adult teeth are called?secondary or permanent teeth
- 27Children teeth known as?deciduous, primary, or baby teeth
- 28Identify parts of tooth
- 29Describe each 1. Dentin 2. Enamel 3. Cementum1. calcified CT (similar to bone but AVASCULAR)
2. acellular, avascular, highly calcified. Hardest substance found in body
3. calcified, avascular CT - 30Pharynx - composed of?mucosa & muscularis externa
***NASOPHARYNX NOT IN DIGESTIVE TRACT*** - 31Esophagus- located dorsal to trachea IN mediastinum
- passes THROUGH diaphragm
- composed of fibrous CT (adventitia) but no serosa
- upper third contains skeletal muscle - 32Stomach consists of? (layers)- Cardiac region
- Fundus
- Body
- Pyloric region (closed by pyloric sphincter)
- greater & lesser curvature
- 33Stomach Mucosa- mucosa contains large folds: RUGAE
- gastric glands formed from folds -> secrete gastric juice into lumen from gastric pits
- 4 cell types - 34Cell types of gastric glands: (4)1. Chief Cells: secrete pepsinogen
2. Parietal Cells: secrete HCl
3. Mucus Cells: goblet cells
4. G Cells: secrete hormone gastrin - 35Muscularis Externa in Stomach layers:1. longitudinal (outer)
2. circular layer (middle)
3. oblique layer (inner - mostly in body of stomach) - 36Small intestine stretches from? Composed of ?- stretches from pyloric sphincter to ileocaecal valve
- Composed of:
1. duodenum
2. jejunum
3. ileum - 37Epithelial layer of Mucosa in Small Intestine contains:1. Enterocytes: mature intestinal cells specializing in absorption
2. Goblet Cells
3. Endocrine cells: hormones
- endocrine: secrete either SECRETIN or CHOLECYSTOKININ (CCK) - 38What else does Sm. Intestine contain? think absorptionMicrovilli: cell wall itself (brush border)
Villi: highly folded parts of intestine -> project into lumen -> contains a lacteal - 39Crypts of Lieberkuhn- pits that open into intestinal glands
epithelium of crypts contain:
1. Undifferentiated stem cells: give rise to cells found on surface of villi & inside of crypts
2. Goblet cells
3. Endocrine cells
4. Paneth Cells: release immune modulators (such as lysozyme&defensins)
5. Secretory Intestinal Cells: immature enterocytes - 40Plicae circulares?mucosa folded into permanent structures
-> increase surface area - 41Muscularis externa in Sm. intestine is?circular & longitudinal
- 42Peyer's Patches?-located in ileum
- groups of lymph nodules acting as immune defences against pathogens encountered along digestive tract - 43Pancreas- retroperitoneal
- like a tadpole (head, body, tail)
contains both exocrine and endocrine glands - 44Exocrine portion in Pancreas:- acinar cells: glandular epi
^ secrete pancreatic juices into ducts
- function: buffer acidity of chyme - 45Endocrine glands in Pancreas:- composed of cells called Islets of Langerhans
Function: secrete insulin & glucagon
^ blood-sugar regulating hormones - 46Liver:- Hepatic cells -> produce Bile
Bile -> secreted into canals
Function: filter material (nutrients & toxins) - 47Hepatopancreatic Duct?drains bile & pancreatic juice into duodenum
- 48Gall Bladder:- muscular sac
- Simple columnar epi
- lacks submucosal layer
- contains rugae
- Function: concentrate & store bile between meals - 49Large Intestine includes: (7)1. Caecum & appendix
2. Colon
3. Hepatic Flexure (right)
4. Splenic Flexure (left)
5. Haustra (pocket-like sacs along colon)
6. Anal canal
7. Anus (w/ 2 sphincters) - 50Layers of Large Intestine:1. Mucosal Layer (not in anal canal)
2. Submucosa
3. Muscularis Externa: circular & longitudinal - 51Muscularis Externa of Large Intestine:Circular: complete extending around circumference
Longitudinal: bands reduced to 3 layers: incomplete
^ called teniae coli: give rise to haustra - 52External Surface of Large Intestine:teniae coli, haustra & epiploic appendages (fat-filled sacs)
- 53Internal surface of Large Intestine:intestinal glands: composed of goblet, absorptive & secretory cells
- lacks folds and villi
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- Flashcards on Anatomy - Digestive System, created by Danica Cuddeford on 31/12/2016.
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- Danica Cuddeford
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