Digestive and Urinary Systems PDF

The Digestive System The digestive system is formed of a tube called alimentary tract (gut) and accessory glands A. Tube: 1.Mouth. 2.Pharynx 3.Esophagus 4.Stomach...

The Digestive System The digestive system is formed of a tube called alimentary tract (gut) and accessory glands A. Tube: 1.Mouth. 2.Pharynx 3.Esophagus 4.Stomach 5.Small intestine 6.Large intestine B. Glands: - Salivary Glands - Pancrease - Liver - Gallbladder  1. Mouth consists of 2 parts : vestibule of the mouth mouth cavity proper -space between the gum, teeth (internally) and the The roof: cheek and lips (externally) of the mouth is formed by the palate and uvula the floor is formed of the tongue The Vestibule of the mouth Receives the opening of the duct of parotid gland (opposite the upper second molar tooth) Teeth incisors canine Two types: molars incisors 1- Milk (deciduous) teeth: canine Temporary teeth present premolars in the children, 20 in number 10 above and 10 below. 2- Permanent teeth: molars They are 32 teeth, 16 above and 16 below, arranged in each half of jaw as follows: 2 incisors, canine , 2 premolars, 3 molars. Palate Separates the mouth uvula cavity from the nasal cavity and formed of: Hard palate Soft palate Posterior muscular part. Anterior bony part. Its most posterior part is called uvula  Mouth Tongue Formed of muscles covered with mucous membrane. Sulcus terminalis divides the tongue into:. posterior 1/3 Anterior 2/3  Tongue Anterior 2/3 (oral part) Posterior 1/3 (pharyngeal part) Contains lingual papillae Contains a mass of lymphoid (filiform, fungiform, vallate tissue in the submucosa called and foliate) lingual tonsil  Saliva and salivary glands Saliva is a colorless liquid that moistens the mouth, begins the digestive process, and lubricates food during chewing and swallowing. three pairs of salivary glands secrete saliva that is carried by ducts into the mouth. sublingual gland half the size of the submandibular Parotid gland Below and Infront the ear largest submandibular gland (below the mandible) half the size of the parotid.  Pharynx 1 2 3 C6 C6 It is a funnel-shaped muscular tube It begins at the base of the skull Ends at the level of the 6th cervical vertebra (C6) where the oesophagus begins. The cavity of pharynx is divided into 3 parts: 1- Nasopharynx 2- oropharynx and 3- laryngopharynx. Esophagus ✓ muscular tube. ✓ Begins at the level of C6 as a continuation of the pharynx ✓ It descends in front of vertebral column ✓ Posterior to trachea and heart ✓ Pierces the diaphragm at the esophageal hiatus (opening) at the level of T10. ✓ Ends at the cardiac end of the stomach at the level of T11 So it has 3 parts; short cervical part, long thoracic part and very short abdominal part.  Stomach Cardiac end The stomach has the following features: 2 ends: Cardiac end where the esophagus ends (guarded by functional sphincter) pyloric end where the duodenum begins. It is guarded by anatomical sphincter ( pyloric sphincter) pyloric end  Stomach 2 curvatures (borders): Fundus Lesser curvature (right border) greater curvature (left border). Lesser curvature 3 parts: Body Fundus body Pyloric part Pyloric part Greater curvature  Small Intestine ✓ Length: 20 feet. ✓ Diameter: 1 inch. ✓ Extend from the pylorus to the ileocecal junction. ✓ Parts: 3 parts Duodenum: 10 inches (25 cm) Jejunum: 2.5 meters (8 feet) Ileum: 3.5 meters, (12 feet)  6. Large Intestine Parts: 1.Caecum: 6 6 2.Vermiform appendix: 4 3.Ascending colon. 5 4.Rt colic flexure 5.Transverse colon. 3 7 6.Left colic flexure 7.Descending colon. 1 2 8. Sigmoid (pelvic) colon. 8 9 9. Rectum. 10 10. Anal canal  6. Large Intestine It is 1.5 meter in length, wider lumen and has 3 main characters: ❖ Taenia coli : 3 bands of longitudinal muscle fibers ❖ Sacculations or haustrations: dilatations in the wall of the colon ❖ Appendices epiploicae : many small sacs containing fat  Differences between small & large Intestine LARGE INTESTINE SMALL INTESTINE Wider and shorter Narrower and longer 1.5 meter 6 meters Greater part is fixed. Greater part is mobile. Tinea coli are present No Haustrations No Appendices epiploicae No  Liver It is the largest gland in the body 1.5 – 2kg wt. It lies in the right upper quadrant of the abdominal cavity just inferior to the diaphragm. It is divided into four lobes 2 large lobes right lobe Caudate lobe left lobe 2 Small lobes Lt lobe the caudate lobe (posterior surface) quadrate lobe (inferior surface) Quadrate lobe Rt lobe  Liver Blood supply of the liver: hepatic artery and portal vein. liver secretes bile which is collected by the biliary system. N.B The term hepatic means pertaining to the liver (hepat means liver, and -ic means pertaining to) as Hepatitis , hepatomegaly, ….  Gallbladder - A pear-shaped sac that lies at the lower surface of the right lobe of the liver. - It has 3 parts : - fundus - body - neck - It stores and concentrates bile - The bile leaves the gallbladder through the cystic duct Applied anatomy: -cholecystitis means Inflammation of gallbladder -cholecystectomy means removal of gallbladder  Biliary System Liver secretes the bile through the right and left hepatic ducts They unite forming the common hepatic duct. Gall bladder receives the bile and evacuates it through the cystic duct The common hepatic duct unites with the cystic duct to form the common bile duct The common bile duct unites with the pancreatic duct to form the hepatopancreatic duct which opens into the middle of the second part of the duodenum.  Pancreas body tail It is a soft lobulated mixed gland located transversely behind the stomach. neck It consists of head, neck, body head and tail. The head is the largest and thickest part and lies in the right side, in the concavity of the duodenum. The tail is the narrowest part and lies in the left side, reaching the hilum of the spleen.  Pancreas Function : it is a mixed gland having : Endocrine function: secretes main pancreatic Insulin hormone: lowers the blood glucose level. duct Glucagon hormone: Elevates the blood glucose level. Exocrine function: secretes pancreatic enzymes in the pancreatic juice which helps the digestion of fat. The pancreatic juice is secreted through the pancreatic ducts (Main and accessory accessory) pancreatic duct  Abdominal Regions For easy localization of organs and description of pains, The abdominal cavity is divided by 4 planes into 9 regions 2 horizontal planes: -Subcostal plane, at the level of L3 -Itertubercular plane at the level of L5 2 vertical planes: Rt and Lt midclavicular planes Abdominal Regions Rt Lt Hypochondrium Epigastric Hypochondrium Rt Lumbar Lt Lumbar umbilical Rt Iliac hypogastric Lt Iliac Abdominal Regions Three central regions (epigastric, umbilical, hypogastric (pubic) Three regions on each side hypochondrium, lumbar (flank) , iliac (groin or inguinal).  Abdominal Region Organs inside Right hypochondrium - Liver – gallbladder – right colic flexure – upper part of right kidney – small intestine Epigastrium - Stomach – liver –- pancreas - duodenum - Small intestine - part of spleen Left hypochondrium - Spleen - stomach –– pancreas – left colic flexure – upper part of left kidney Right lumbar (flank) - Right kidney - ascending colon - Small intestine – right ureter Umbilical - Pancreas - small intestine – transverse colon Left lumbar - Left kidney - left ureter - Descending colon - small intestine Right iliac ( groin) - Small intestine - cecum - appendix - ascending colon Pubic (hypogastrium) - Urinary bladder – sigmoid colon - rectum – uterus and ovaries Left iliac ( groin -small intestine - descending colon – sigmoid colon  The Peritoneum ✓ Peritoneum is a serous membrane. ✓ It has 2 layers: 1. Visceral layer– surrounds abdominal and pelvic organs 2. Parietal layer – lines the abdominal and pelvic cavities 3.peritoneal cavity: Between both layers  Relation of pelviabdominal organs to peritoneum ✓ 1- primary retroperitoneal organs ✓ (developed behind peritoneum from the start) ✓ as kidney and suprarenal glands Relation of pelviabdominal organs to peritoneum ✓ 2- secondary retroperitoneal organs ✓ Duodenum, pancreas, ✓ ascending colon and descending colon  Relation of pelviabdominal organs to peritoneum ✓ 3- intraperitoneal organs ✓ ( expansile or mobile) ✓ Liver, stomach, spleen, small intestine ✓ , uterus, transverse colon Peritoneal relations of the organs help to understand the relations of organs Lt Kidney – pancreas – stomach Rt Kidney – duodenum – transverse colon Also liver is anterior to stomach while spleen is posterior to it  Relation of abdominal organs to peritoneum Retroperitoneal Intraperitoneal Primary Liver Kidney and suprarenal gland Spleen Secondary Stomach Duodenum Transverse colon Pancreas Jejunum and ileum Ascending colon Uterus Descending colon Ovary Sigmoid colon  Peritoneal folds 2 layers of peritoneum - Between abdominal organs or - Between organs and abdominal wall Named according to the related organ: - attached to stomach = omentum - Attached to intestine = mesentery - Attached to other organs as liver , spleen = ligament Paritoneal Folds attached to stomach: Lesser omentum attached to lesser curvature of stomach greater omentum attached to greater curvature of stomach It helps to prevent spread of infection ( policeman of the abdomen) Mesenteries Sagittal section through the abdominopelvic cavity Mesentery of Small intestine Mesenteries mesentery of transverse colon mesentery of sigmoid colon mesentery of the appendix (Mesoappendix)  Peritoneal Ligaments splenorenal (lienorenal) ligament falciform ligament Between liver and anterior abdominal wall Gastrosplenic ligament URINARY SYSTEM  Urinary system Urinary system is formed of: 1- Kidneys (right & left) produce urine. 2- Ureters (right & left) Transport urine to the urinary bladder. 3- Urinary bladder. stores urine before elimination. 4- Urethra Conduct urine to outside  Kidney Position of the kidney: ✓The kidney is a 1ry retroperitoneal organ ✓It lies opposite: T12 to L3 vertebrae ✓RT kidney is lower than the Lt kidney (due to large size of right lobe of liver) : The RT kidney is related to 12th rib only The LT kidney is related to 11th & 12th ribs  The kidney Shape : bean shape It has - 2 poles :upper and lower - 2 surfaces : anterior and posterior - 2 borders : medial and lateral ✓ The lateral border is convex & medial border is concave in the middle & contains the hilum. ✓ The hilum contains: 1. Renal vein → (anterior). 2. Renal artery → (intermediate). 3. Renal pelvis → (posterior & is directed downward). 4. Lymph vessels. 5. Sympathetic fibers.  The kidney External features of the kidney: Surfaces: ✓ Anterior surface: Posterior surface: Retroperitoneal. Not covered with peritoneum Related to the abdominal organs Related to muscles of the posterior abdominal wall and the ribs (11th & 12th in Lt. and 12th in Rt.).  Coverings of the kidney 1. Fibrous capsule (covers the kidney) 2. Perirenal fat (covers the capsule – main supporting factor) 3. Renal fascia (outside the perirenal fat, it encloses the kidney & suprarenal gland) 4. Pararenal fat: covers the fascia (forms retroperitoneal fat, its amount is variable)  The internal structure of the kidney: Cortex: it is the outer pale colored part lying deep the renal capsule. Medulla: it is the inner dark colored part lying on the inner aspect of the cortex. The medulla is divided into many pyramids (triangular sectors). Each pyramid has a base and an apex which is directed towards the hilum. The apex is surrounded by minor calyces that collect urine and unite to form the major calyces which Unite to form the renal pelvis (expanded upper part of ureter Functions of the kidney: 1. Remove metabolic waste products from the blood. 2. Secrete the hormone erythropoietin, which stimulates bone marrow to produce red blood cells. 3. Secrete the hormone renin, which helps regulation of blood pressure.  The kidney THE NEPHRON: - Is the functional unit of the kidney -Each kidney contains about 1 million nephrons. -The nephron is made of : -Bowman’s capsule, -Proximal convoluted tubule - loop of Henle -Distal convoluted tubule -Collecting duct.  The kidney Blood supply of the kidney: Renal artery arises from abdominal aorta. Renal vein ends in inferior vena cava. URETER  The ureter ✓ The ureter is a muscular tube, ✓ The average length is 25 cm ✓ The upper expanded part is the renal pelvis ✓ Ureter proper begins at the lower pole of the kidney ✓ it descends in the abdomen on both sides of the vertebral column. ✓ It crosses the bifurcation of the common iliac artery to enter the pelvis.  The ureter has 4 sites of constrictions: 1. At the beginning (where renal pelvis joins ureter) 2. Where it crosses common iliac artery: 3. 3. At the level of ischial spine 4. At its end: as the ureter enters the urinary bladder Clinical significance : These are the sites of stone impaction Blood supply of the ureter: ✓The ureter is supplied from the following arteries: 1. Abdominal aorta 2. Renal artery. 3. Gonadal artery. 4. Common iliac artery. The urinary bladder  The urinary bladder ✓ Position: ❑in infants, it is an abdominal organ (due to narrow pelvis) ❑ in adults, it becomes pelviabdominal organ (by widening of the pelvis) ✓ Capacity: ✓ in adult → maximum capacity is 400 -600 ml.  The urinary bladder Shape: empty bladder is 3-sided pyramid It has 3 surfaces (1 superior and 2 inferolateral), Base , apex and neck) Superior surface base is posterior Apex anterior inferolateral surface The neck Below and continues with urethra  The urinary bladder ✓ Interior pf the urinary bladder ✓ The mucous membrane of the urinary bladder is thrown into folds (rugae). ✓ An interureteric ridge Lies between 2 ureteric orifices. ✓ The part of the mucous which lies between the ureteric orifices & the internal urethral orifice is called the trigone.  The urinary bladder ✓ The smooth muscles in the wall of the urinary bladder and the internal urethral sphincter ( in the neck) are involuntary and supplied by autonomic nervous system ✓ The external urethral sphincter is skeletal and voluntary and supplied by somatic nerves Urethra  Male urethra It extends from the internal urethral meatus at neck of bladder to external urethral meatus ( at the glans penis) - 18 – 20 cm - Passage for urine and semen - Consists of 4 parts - Preprostatic part - Prostatic part - Membranous part - Spongy (penile) part  Male urethra 4 parts: 1- Preprostatic part 1- 2 cm, surrounded by internal urethral sphincter (smooth , involuntary) 2- Prostatic Widest part 3 cm in length, it receives the openings of ejaculatory ducts. 3- Membranous Narrowest part 1- 2 cm in length, surrounded by sphincter urethrae (external urethral sphincter, skeletal, voluntary). 4- Spongy ( penile) 15 cm, it receives the openings of bulbourethral glands Male urethra Preprostatic part Prostatic Membranous Spongy ( penile) Note the bulbourethral gland Coronal section of male urethra  Female urethra - 4 cm - Passage for urine only - Embedded to the anterior wall of vagina - It extends from the internal urethral meatus (neck of the bladder) - to the external urethral meatus at vestibule of vagina - Also has 2 sphincters - Internal urethral sphincter - External urethral sphincter THANK YOU