The GI System 1-3 (2024) PDF

WEEK 15 The GI System A group of organs that work together to break down √ ingested food into smaller, absorbable nutrient molecules that can then be absorbed into blood for distribution to all the cells in...

WEEK 15 The GI System A group of organs that work together to break down √ ingested food into smaller, absorbable nutrient molecules that can then be absorbed into blood for distribution to all the cells in the body Slide 4 of 83 MPharm PHA115 GI System WEEK 15 The GI System Main functions Digests or biochemically breaks down ingested food into small, simple nutrient molecules Absorbs & transfers the nutrient molecules, electrolytes & water derived from the ingested food into systemic circulation 전해질 물 영양송 보충 , , Makes the preformed organic nutrient molecules in ingested food available to body cells to be used as sources of fuel or energy building blocks Slide 5 of 83 MPharm PHA115 GI System WEEK 15 The GI System Performs 5 basic digestive processes Motility Secretion Digestion Absorption Storage & elimination of indigestible food Slide 6 of 83 MPharm PHA115 GI System WEEK 15 The Digestive System Motility 근육의 움직임을 통해 이동시키는 것. Muscular contractions that mix & move the contents of the digestive tract forward Two types of digestive motility Propulsive movements propel or push contents forward through the digestive tract 앞으로 ! Mixing movements " 소화액과 섞이게 해 mix food with digestive juices & promote digestion facilitate absorption of digested food Slide 7 of 83 MPharm PHA115 GI System  The GI System WEEK 15 Secretion 1분비 ) Several digestive juices secreted in GI tract in response to specific neural or hormonal stimulation Consist ofROs water, electrolytes & specific organic constituents (enzymes, mucus, etc) ^ Include both exocrine & endocrine secretions Exocrine – secreted into the lumen of GI tract m≈ H2O, HCl, HCO3-, bile, lipase, pepsin, amylase, trypsin & histamine → 혈액측으로 Endocrine – secreted into the blood stream Gastrin, secretin, CCK, VIP & somatostatin Slide 8 of 83 MPharm PHA115 GI System WEEK 15 The GI System Digestion (소화] Complex s Smaller Biochemical breakdown of complex foodstuffs into →≈ smaller, absorbable units→ (chemical digestion) × Accomplished by enzyme-mediated ≈ hydrolysis ≥ Complex foodstuffs & their absorbable units Carbohydrates → monosaccharides Proteins → amino acids (AA ) Fats → glycerol & fatty acids ^ Slide 9 of 83 MPharm PHA115 GI System WEEK 15 The GI System Absorption (흡수) Transfer of small digested units, along with water, vitamins & electrolytes, from the GI tract into blood GI s blodo or lymph - ymph Occurs largely & most completely in the small intestine Slide 10 of 83 MPharm PHA115 GI System WEEK 15 Functional Anatomy of The Gastro-intestinal (Digestive) System Slide 11 of 83 MPharm PHA115 GI System WEEK 15 The GI System -침셈 ? e Slide 12 of 83 MPharm PHA115 GI System  The GI System WEEK 15 Gross Structure & Organisation Also called the Gastrointestinal (GI) Tract Comprises 2 main components The alimentary canal long, continuous hollow tube stretching from the mouth to the anus (~30 feet long) Accessory organs & glands Salivary glands Liver & Pancreas Slide 13 of 83 MPharm PHA115 GI System WEEK 15 Alimentary canal Accessory digestive – Continuous from mouth organs to anus – Salivary glands – Consists of – Exocrine pancreas Mouth – Biliary system Pharynx Liver Oesophagus Gallbladder Stomach Small intestine – Duodenum – Jejunum – Ileum Large intestine – Caecum – Appendix – Colon – Rectum Anus Slide 14 of 83 MPharm PHA115 GI System WEEK 15 The GI System The Alimentary Canal Gross Functional Organisation Divided into 3 main parts Upper part the mouth, oesophagus & stomach 업 식도 배 serves as food intake source & receptacle site of initial digestive processes Slide 15 of 83 MPharm PHA115 GI System WEEK 15 The GI System The Alimentary Canal Gross Functional Organisation Divided into 3 main parts (cont’d) Middle part 망 the small intestine – duodenum, jejunum & ileum site of main digestive & absorptive processes Slide 16 of 83 MPharm PHA115 GI System WEEK 15 The GI System The Alimentary Canal Gross Functional Organisation Divided into 3 main parts (cont’d) Lower part the large intestine – caecum, colon & rectum serves as the storage channel for efficient elimination of waste Slide 17 of 83 MPharm PHA115 GI System WEEK 15 Wall Structure of Alimentary Canal Slide 18 of 83 MPharm PHA115 GI System WEEK 15 Wall Structure of Alimentary Canal Slide 19 of 83 MPharm PHA115 GI System WEEK 15 Wall Structure of Alimentary Canal Comprises 4 layers DD Mucosa →점 innermost, moist, folded lining of epithelial cells, connective tissue & smooth muscle cells main functions protective barrier against pathogens, etc secretes mucus, digestive enzymes & hormones 점액. absorbs digested nutrients into the blood undergoes rapid cell division & regeneration Slide 20 of 83 MPharm PHA115 GI System WEEK 15 Wall Structure of Alimentary Canal Comprises 4 layers ② Submucosa dense connective tissue layer containing blood and lymphatic vessels, lymphoid follicles & nerve fibres contains the submucosal nerve plexus of Meissner main functions provides the digestive tract with distensibility and elasticity censen glands secrete digestive enzymes of rene cels ∞ nerve plexus helps regulate gut motility Slide 21 of 83 MPharm PHA115 GI System WEEK 15 Wall Structure of Alimentary Canal Comprises 4 layers ③ Muscularis externa ㆁ consists of inner layer of circular smooth muscle & outer layer of longitudinal smooth muscle ∞ myenteric plexus of Auerbach lies in between main functions contractions facilitate mixing & movement of food contents (peristalsis & segmentation) intrinsic nerve plexus helps regulate gut motility Slide 22 of 83 MPharm PHA115 GI System WEEK 15 Wall Structure of Alimentary Canal Comprises 4 layers ④ Serosa outer connective tissue & epithelial covering continuous with the mesentery ? main functions ~ secretes a watery, slippery serous fluid  lubrication and  friction between digestive organs & surrounding viscera Slide 23 of 83 MPharm PHA115 GI System WEEK 15 Complex Extrinsic & Intrinsic Regulation of Digestive Function Mediated via Interstitial cells of Cajal (pacemaker cells)  slow-wave potentials (BER)  spontaneous rhythmic electrical activity Intrinsic nerve plexuses (ENS)  GI muscle contraction or relaxation ∞ : egulateD - Extrinsic nerves (ANS)  increase or decrease GI contraction & secretion Gastrointestinal hormones  increase↑or decrease서 GI contraction & secretion aprt Local sensory receptors – chemoreceptors, mechanoreceptors & osmoreceptors su istote fmsck Slide 24 of 83 totrin MPharm hid PHA115 , GI System respond WEEK 15 Complex Extrinsic & Intrinsic Regulation of Digestive Function Slide 25 of 83 MPharm PHA115 GI System WEEK 15 Complex Extrinsic & Intrinsic Regulation of Digestive Function Slide 26 of 83 MPharm PHA115 GI System WEEK 15 Digestive Processes ( 똥 Slide 27 of 83 MPharm PHA115 GI System WEEK 15 Digestive Processes From Mouth to Stomach Slide 28 of 83 MPharm PHA115 GI System  From Mouth to Stomach WEEK 15 Mastication (chewing) Aids in mechanical breakdown of larger food units Mixes food with saliva which contains salivary amylase  partial digestion of starch ( 침과 섞에 Saliva moistens ingested food, lubricates & exerts antibacterial effect Deglutition (swallowing) oropharyngeal stage oesophageal stage Slide 29 of 83 MPharm PHA115 GI System WEEK 15 Swallowing Oropharyngeal stage " 음식이 기도로 가지 않게 , Movement of the bolus through the pharynx into the oesophagus 인두 - ' 식도 Slide 30 of 83 MPharm PHA115 GI System  Swallowing WEEK 15 Oesophageal stage Slide 31 of 83 MPharm PHA115 GI System