浙江大学医学院：胃肠道生理（PPT讲稿）Gastrointestinal Physiology

Gastrointestinal Physiology Liang huawei, ph D E-mail:lianghuawei@aliyun.com

Gastrointestinal Physiology Liang Huawei, Ph.D. E-mail: liang.huawei@aliyun.com

Anatomy of gastrointestinal system GI tract Accessory organs ESOPHAGUS PANCREAS COLON APPEND RECTUM

Anatomy of gastrointestinal system ◼ GI tract ◼ Accessory organs

Functions of gastrointestinal system Movement: propels food through the digestive system Secretion release of digestive juices in response to a specific stimulus Digestion breakdown of food into molecular components small enough to cross the plasma membrane Absorption passage of the molecules into the body,'s interior and their passage throughout the bod Elimination: removal of undigested food and wastes

Functions of gastrointestinal system ◼ Movement: propels food through the digestive system ◼ Secretion: release of digestive juices in response to a specific stimulus ◼ Digestion: breakdown of food into molecular components small enough to cross the plasma membrane ◼ Absorption: passage of the molecules into the body's interior and their passage throughout the body ◼ Elimination: removal of undigested food and wastes

Blood flow Hepatic rtal vein +地计+计 Anus wate**3 Feces Rectum Small intestine Stomach

Physiological properties of gastrointestinal smooth muscle 消化道平滑肌的特性 General properties(一般特性) o Low excitability o High distensibility(扩张性) o Tonic contraction o Autorhythmicity o High sensitivity to temperature, stretch and chemical stimulation

Physiological properties of gastrointestinal smooth muscle 消化道平滑肌的特性 ◼ General properties (一般特性)  Low excitability  High distensibility (扩张性)  Tonic contraction  Autorhythmicity  High sensitivity to temperature, stretch and chemical stimulation

Electrophysiological properties(电生理 特性) o Resting membrane potential 50~-60mV lonic basis o Em(selective membrane permeability to K+, Nat Cl and Cazt) o Electrogenic Na*-K* pump

◼ Electrophysiological properties (电生理 特性)  Resting membrane potential ◼ −50 ~ − 60 mV ◼ Ionic basis  Em (selective membrane permeability to K+ , Na+ , Cl− and Ca2+)  Electrogenic Na+ -K+ pump

Slow wave(慢波电位)/ Basic electrical rhythm(BER,基本电节律) The spontaneous rhythmic, subthreshold depolarizations of the cell membrane(slow wave)of the gastrointestinal tract Initiated in the interstitial cells of Cajal (ICC) (pace maker cell

 Slow wave (慢波电位) / Basic electrical rhythm (BER, 基本电节律) ◼ The spontaneous rhythmic, subthreshold depolarizations of the cell membrane (slow wave) of the gastrointestinal tract ◼ Initiated in the interstitial cells of Cajal (ICC) (pace maker cell)

Santiago Ramon Y Cajal He and camillo golg received the nobel prize 李确 in 1906 for introduction of the silver-chromate (铬酸银) stain x

Santiago Ramon Y Cajal ◼ He and Camillo Golgi received the Nobel Prize in 1906 for introduction of the silver-chromate （铬酸银）stain

Slow wave/ Basic electrical rhythm ( BER) o Intensity: 10-15 mV o Frequency: 3-12 cpm o lonic mechanism spontaneous rhythmic changes in Nat-Kl pump activity

◼ Slow wave / Basic electrical rhythm (BER)  Intensity: 10~15 mV  Frequency: 3~12 cpm  Ionic mechanism ◼ spontaneous rhythmic changes in Na+ -K+ pump activity