W1: the abdominal cavity Flashcards
what is the cavity
- large hollow space that incudes those in digestion and excretion
- lined by protective membrane (peritoneum)
- organs include: stomach, liver, pancreas, kidney, spleen, intestines, blood vessels and nerves
- below thoracic cavity and above pelvic cavity
- superior is diaphragm
- inferior is pelvic brim
- ant and lat is abdominal wall
- post is vert column, back muscle and pos abd wall
abdominal quadrants
4 quadrants intersecting at the umbilicus
RUQ: liver (right lobe), gallbladder, stomach (pylorus), duodenum, pancreas (head), right kidney, adrenal gland, parts of asc and trans colon
LUQ: liver (left lobe), left kidney, stomach, spleen, pancreas (tail and body), parts of trans and desc colon
RLQ: caecum, appendix, right ureter, right ovary, right fallopian tube, spermatic cord, parts of small intestine
LLQ: left ureter, left ovary, left fallopian tube, spermatic cord, desc and sigmoid colon, parts of small intestine
name abdominal regions
9 regions- 2 hor and 2 vert
sup- epigastric region with hypochondriac regions on left and right
middle- umbilical region with flank regions and left and right
inf- hypogastric region with iliac fossa regions on left and right
describe the 9 regions
right hypochondriac- liver, gallbladder, right kidney, colon
epigastric region- liver, stomach, spleen, duodenum, adrenal gland, pancreas
left hypochondriac- spleen, stomach, pancreas (tail), left kidney, colon
right flank- asc colon, right kidney, small intestine
umbilical- small intestine, trans colon, parts of pancreas
left flank- desc colon, left kidney, small intestine
right iliac fossa- caecum, appendix, small intestine, asc colon
hypogastric- bladder, small intestine, sigmoid colon, reproductive organs
left iliac fossa- sigmoid colon, small intestine, desc colon
where is the abdominal wall
- surrounds cavity
- bounded superiorly by xiphoid process and costal margins
- posteriorly by vert column
- inf border are pelvic bones and inguinal ligament
what are the anterolateral muscles
- rectus abdominis
- external oblique
- internal oblique
- pyramidalis
- transversus abdominis
describe the layers of the abdominal wall
3 outside, 3 middle, 3 inside
outside: skin, camper fascia and scarpa fascia
middle: external obliques and aponerosis, internal obliques and aponeurosis, transverse abdominis muscle and aponeurosis
inside: transversalis fascia, extraperotineal fat, parietal peritoneum
fascia- connective tissue surrounding and supporting organs/ muscles/ vessels
aponeurosis- white fibrous tissue that take place of tendon in flat muscles
peritoneum
serous membrane that lines cavity and most organs
supported organ and provide lubricanted surface 4 reduced friction
large folds that weave between organs and bind them to one another and wall
comprised of 2 layers: parietal and visceral
parietal- line inner surface of abdominal and pelvic walls & sensitive to touch, pain, pressure and temp
visceral- line outer surface of most organs & insensitive to pressure, pain, temp and touch
in between is lubricanting serous fluid- peritoneal cavity
specialised peritoneum
mesentery: double layer of perotineum containing blood vessels and nerves + suspends the small and large bowel from wall
greater omentum: sheets of perotineum extending from stomach over intestine
lesser omentum: connects stomach and duodenum to liver
ligaments: double layers of perotineum connect organs to each other or the wall such as FALCIFORM ligament which connects liver to ant wall and diaphragm
areas of peritoneum
intraperitoneal area: organs completely covered by visceral peritoneum e.g. stomach, liver, jejenum (parts of small intestine)
retroperitoneal area: organs that lie on post abdominal wall and are above red by peritoneum only on their anterior surface e.g. kidney, asc and desc colon, duodenum and pancreas
infection within peritoneal cavity is peritonitis
abdominal fluid build up within cavity is ascites
contents of abdominal cavity
- distal oesophagus
- stomach
- small inestine
- colon
- gall bladder
- liver
- pancreas
- spleen
- kidneys, ureters, bladder
- adrenal glands
- abdominal wall, nerves and lymphatics
digestive system
- composed of digestive canal/ GI tract extends thru the thoracic and abdominal cavities from the oesophagus to the anus
- organs: oesophagus, stomach, small intestine, large intestine, anal canal
- length is about 5-7 metres
- accessory organs: tongue, pancreas, kidney, liver, salivary glands, pharynx, mouth, teeth
- canal contains food that is then digested, absorbed or eliminated
- muscular contractions break down the food and propel is almond he canal
GI tract
4 main layers make up the walls
- outer layer: serosa provides protection and reduces friction
- 2 muscle layers: inner circular and outer longitudinal for peristalsis and segmentation
- submucosa: contains glands that’s secrete digestive enzymes
- mucosa: innermost layer that lines lumen and secrete mucus and enzymes
categories of digestive system
3 distinct sections: foregut, midgut, hindgut
foregut: mouth, pharynx, oesophagus, stomach, liver, gall bladder, pancreas and duodenum
midgut: jejenum, ileum, caecum, asc colon, part of trans colon
hindgut: part of trans colon, desc colon, sigmoid colon, rectum, anus
stomach
- j shaped intraperitoneal organ located dreictly inferior to diaphragm in the LUQ
- connects oesophagus to the duodenum
- breaks down food mechanically and chemically
- distensible to accommodate large quantities of food
divided into 4 parts:
- cardia- contains cardiac sphincter which stops content flowing backwards
- fundus- upper rounded part
- body- central largest part
- pylorus- lower part which concurs duodenu and pyloric sphincter
- has 3rd muscle layer (inner layer made of oblique fibres)
small intestine
- longest section of GI tract
- c shaped duodenum wraps around head of pancreas
- 5m long and 2.5cm diameter
- chem digestion of food and absorption of nutrients occurs
- made up of duodenum, jejenum and ileum
- empties into colon and iliocaecal valve (caecum)
- jejenum and ileum are attached to post abdominal wall by mesentery
large intestine (colon)
- 1.5m long, 5cm diameter
- starts at caecum with vermiform appendix
- absorption of fluids and vitamins
- processing indigestible food material drives contents of colon into rectum
- bacteria in large inestine convert proteins to amino acids, break down amino acids and produce some B and K vitamins
- formation of faeces
- defecation
- peristalsis is limited to 4-6 large movements a day
anatomy of large intestine
- ascending colon
- hepatic flexure
- transverse colon
- splenic flexure
- descending colon
- sigmoid colon
- rectum
- anal canal
rectum and anal canal
rectum:
commences at distal end of sigmoid colon at S3
anal canal:
4 cm in length
surrounded by internal sphincter
internal anal sphincter is surrounded by a band of skeletal muscle which forms external anal sphincter
liver
- heaviest gland in body
- lies inferior to diaphragm in right hypochondriac and epigastric region
- mostly intraperitoneal and covered with visceral peritoneum but has small bare area posteriorly (retroperitoneal)
- divided into 2 lobes, large right and small left by falciform ligament
- 2 smaller lobes: quadrate and caudate
- provide essential function like processing nutrients, filter toxins and produce bile to aid in digestion and store glycogen
- high vascular, receive blood from hepatic artery and portal vin
gall bladder
- pear shaped sac located on visceral surface of liver in fossa of GB
- fundus, body and neck
- 7-10 cm long
- hangs from ant, inf margin of over
- almost covered in visceral peritoneum
- stores and concert areas bile until needed in duodenum
pancreas
- flattened elongated structure bout 12-15cm long and 2.5cm thick
- retroperitoneal organ of left hypochondriac region
- situated post to greater curvature of stomach
- head, neck, body and tail
- tail points towards spleen
- head has small hook structure projection called uncinate process
- connected to duodenum by 2 ducts: pancreatic and common bile
- has exocrine and endocrine functions: produces pancreatic juice that aids digestion and hormones
spleen
- located in left hypochondriac region
- intraperitoneal organ (surrounded by visceral and capsule)
- diaphragm, stomach, left kidney and splenic flexure make infections on visceral surface
- consist of white and red pulp
- 12cm long and 7cm thick
- has hilum for artery, vein and lymphatic vessels
connected to stomach and kidney by parts of the greater omentum:
- gastrosplenic ligament: connect spleen to greater curvature of stomach
- splenorenal ligament: connect hilum of spleen to left kidney
urinary tract
upper: kidneys, ureters
lower: bladder, urethra
- retroperitoneal
- 2 bean shaped organs located between T12-L3 partially protected by ribs
- concave medial border face vertebral column
- contains hilum for ureter and vessels
- renal fascia anchors it to surrounding structures and abd wall
- 3 layers: renal fascia, perirenal fat capsule, fibrous capsule
