Abdomen and Pelvis Flashcards
(299 cards)
1
Q
Draw the nine subdivisions of the abdomen.
A
Right hypochondrium, epigastric, left hypochrondrium.
Right lumber, ubilical, left lumbar.
Right inguinal, supra-pubic region, left inguinal.
Horizontal planes are:
- Superior = Transpyloric
- Inferior = Trans-tubercular plane.
2
Q
Where does rectus abdominus originate and attach?
A
Origin = costal cartilages.
Attachment = pubic crest.
3
Q
What is the linea semilunaris?
A
A point where the aponeurotic tendons of the oblique muscles fuse lateral to the rectus abdominus.
4
Q
What is the function of quadratus lumborum?
A
It is found in the posterior of the abdomen and the function is to stabilise the 12th rib for the purposes of breathing.
5
Q
What surrounds the inside of all of the abdominal muscles?
A
Endo-abdominal fascia. Its name is determined by what structure it is covering.
6
Q
What are the layers of superficial fascia in the abdominal wall?
A
Camper’s fascia = most superior layer of fatty fascia.
Scarpa’s fascia = deep membranous fascia that only truly exists in the lower part of the abdomen (from the umbilicus downwards).
7
Q
What is found between the endo-abdominal fascia (specifically the transversalis fascia) and the parietal peritoneum?
A
Extra-peritoneal fat/fascia.
8
Q
What is the enlargement of the superficial veins of the abdomen called and why?
A
Caput medusae.
Because the veins look like the snakes of Medusa’s hair.
9
Q
The tendon of which muscle forms the inguinal ligament?
A
External oblique.
10
Q
Which nerves supply the rectus abdominus and external oblique muscles?
A
They are supplied segmentally by the intercostal nerves from T7-T12.
11
Q
What is the guarding reflex?
A
This is where the muscles on the abdominal wall contract and stiffen in response to stroking stimuli on the skin in order to protect the organs within the abdomen.
12
Q
Where does the internal oblique muscle originate and attach?
A
Origin = iliac bone and the upper 1/3 of the inguinal ligament.
Attachment = ribs 10-12 and linea alba.
13
Q
What is the additional nerve contribution to the lower fibres of the internal oblique?
A
Spinal nerve from L1.
14
Q
What is the conjoined tendon?
A
Where the aponeuroses of the internal oblique and transversus abdominus combine to form a tendon that attaches to the pubic crest.
15
Q
What happens halfway between the umbilicus and the pubic symphysis?
A
The three aponeurotic tendons of the oblique muscle go in front of rectus abdominus where previously they were behind. This point is called the arcuate line.
16
Q
What is a hernia?
A
A protrusion of the peritoneum (and often organs) through the abdominal walls, roof of the abdomen or floor of the pelvis.
17
Q
What hernias are more common in males and females?
A
Males = inguinal hernias.
Females = femoral hernias.
18
Q
What is a strangulated hernia?
A
Where organs have protruded through the hole in the muscle and blood flow has been cut off causing cell death.
19
Q
Where do inguinal and femoral hernias arise?
A
Inguinal = through the superficial ring above and medial the pubic tubercle. Also above the inguinal ligament.
Femoral = below the inguinal ligament and lateral to the pubic tubercle. Through the femoral canal.
20
Q
What makes up the borders of the inguinal canal?
A
Superficial/anterior border = External oblique aponeurosis.
Superior border = transversus abdominus and internal oblique.
Deep/posterior border = transversalis fascia.
Inferior border = inguinal ligament.
21
Q
What forms the inguinal ligament?
A
The inferior border of the external oblique muscle.
22
Q
What is the cremaster muscle?
A
A thin layer of smooth muscle found between the internal and external layers of spermatic fascia. It originates from the internal oblique muscle, just superior to the inguinal canal and the middle of the inguinal ligament.
23
Q
What is the gubernaculum?
A
It is an embryological structure that guides the descent of the ovaries and testes.
In the adult male the lower part becomes the gubernaculum testis (scrotal ligament) and in the adult female it becomes the ovarian ligament and the round ligament of the uterus.
24
Q
What do Camper’s and Scarpa’s fascia become in the scrotum?
A
Camper’s becomes a layer of smooth muscle called Dartos muscle.
Scarpa’s fascia becomes a layer of deep fascia called Colles’ fascia.
25
What do the abdominal muscle layers become in the scrotum?
External oblique = external spermatic fascia.
Internal oblique = cremasteric muscle and fascia.
Transversalis fascia = internal spermatic fascia.
26
What is the inguinal triangle?
An area determined by the lateral margin of the rectus sheath (linea semilunaris), the inferior epigastric vessels and the inguinal ligament.
This area is where direct inguinal hernias occur.
27
What is the difference between a direct and an indirect inguinal hernia?
Indirect hernias travel through the deep and the superficial inguinal rings, whereas the direct hernias just go through the superficial inguinal ring.
28
What are the intra-peritoneal organs?
Organs that are completely surrounded by peritoneum. These organs include:
- Stomach
- Spleen
- Liver
- Bulb of the duodenum
- Jujenum
- Ileum
- Transverse colon
- Sigmoid colon
29
What is a mesentery?
A double-folded layer of peritoneum that allows nerves and vessels to pass through them.
30
What are the retro-peritoneal organs?
Organs that are partly covered by peritoneum which makes them relatively immobile. These organs include:
- Rest of duodenum
- Cecum
- Ascending colon
- Descending colon
- Pancreas
- Kidneys
31
What are the names of the ventral mesentery that are surrounding the liver, stomach, spleen and kidneys?
Falciform ligament connects the liver to the anterior abdominal wall.
Gastrohepatic ligament (lesser omentum) connects the liver to the stomach.
Gastrosplenic ligament connects the stomach to the spleen.
Spleno-(lieno)-renal ligament connects the spleen to the kidneys.
32
Where are the lesser and greater sacs located in the abdomen?
The lesser sac is located behind the stomach, to the right of the duodenum and extends towards the right behind the lesser omentum (gastrohepatic ligament).
The greater sac is everywhere else in the abdomen i.e. in front of the liver and stomach.
33
What is the epiploic/omental foramen?
The hole between the greater and lesser sacs in the abdomen through the lesser omentum.
34
What is the greater omentum derived from?
Dorsal mesentery.
35
What is the gastro-colic ligament?
The mesentery that holds the greater omentum onto the transverse colon.
36
What vessels are found within the lesser omentum?
Hepatic artery, hepatic portal vein and bile duct.
37
What are the mesenteries of the transverse colon and sigmoid colon called?
Transverse mesocolon and sigmoid mesocolon.
38
What is the vesicouterine pouch?
A space made by the fold in peritoneum created by the uterus lying on top of the bladder.
39
What is the pouch of Douglas?
The recto-uterine pouch made by peritoneum.
40
What is the point where the oesophagus becomes the stomach?
The cardiac notch and cardia. Associated with a change in epithelia.
41
What is the incisura angularis?
The inner curvature point where the body of the stomach ends and the pyloric antrum begins.
42
What are the four parts of the stomach?
1. Fundus
2. Body
3. Pyloric antrum
4. Pylorus
43
Why is the oesophageal sphincter misnamed?
There is no true muscular sphincter here, but there is a physiological sphincter in action.
44
What are the functions of the cardia, fundus, body and pyloric antrum?
Cardia = mucus secretion.
Fundus = storage (gas)
Body = storage, mucus, HCl, pepsinogen and intrinsic factors (required for B12 absorption) all secreted.
Pyloric antrum = mixing/grinding of food and gastrin secretion.
45
What are the key functions of the stomach?
- Temporary storage of chyme (max capacity is 2 litres).
- Secreting gastrin and intrinsic factor.
- Breaking down food by churning, secreting pepsin (to break down proteins) and HCL (to allow pepsin action and destruction of bacteria.
- Absorption of water, electrolytes, alcohol and aspirin.
46
What structures are found within the gut mucosa?
- Ducts of accessory glands (e.g. pancreas, liver).
- GALT = gut-associated lymphoid tissue.
- Mucosal glands.
47
What are the three layers that make up the gut mucosa?
1. Epithelium
2. Lamina propria
3. Muscularis mucosa - controls the movement of the epithelium.
48
What is the sub-mucosa of the gut made up of?
- Loose connective tissue
- Blood vessels
- Lymphatics
- Nerves
- Sub-mucosal glands
49
What are the layers of the muscularis externa in the gut and what nerve plexus supplies them?
- Outer longitudinal
- Inner circular
- Inner oblique (additional layer only found in the stomach).
Myenteric (Auerbach's) plexus (controls its own activity).
50
What is found within the adventitia or serosa of the gut?
- Connective tissue (adventitia) or peritoneum (serosa).
- Extrinsic nerves that influence the myenteric plexus.
- Blood vessels.
51
What are the folds within the stomach called?
Rugae
52
Where are the veins that drain the stomach mainly located and where do they drain into?
Around the lesser and greater curvatures of the stomach. They all drain into the hepatic portal vein.
53
Where does the lower part of the oesophagus drain into?
The azygous vein
54
Where does all of the lymphatic drainage of the stomach end up?
Pre-aortic lymph nodes i.e. the coeliac lymph nodes that are at the coeliac trunk.
55
What are the functions of the vagus nerve and the stomach?
Motor and secretomotor. Parasympathetic.
56
What are the sympathetic nerves that innervate the stomach and what are their functions?
T6-T9
- Afferent (pain from the stomach).
- Efferent = vasoconstriction and antiperistaltic.
57
Between what ribs does the spleen sit?
9-11
58
What are the functions of the spleen?
- Removes blood-borne antigens (immunity).
- Removes and destroys old/damaged blood cells.
- Stores red blood cells and platelets.
- Responsible for haemopoiesis (production of blood cells and platelets) in the foetus.
59
What are the two poles of the spleen?
Upper = gastric
Lower = colic
60
What are the two surfaces of the spleen?
1. Diaphragmatic
| 2. Visceral (renal)
61
What might an enlarged spleen be due to?
- Liver disease
- Blood cancers
- Infections
- Abnormal blood flow and congestion (in cases of portal hypertension or cardiac failure)
- Gaucher disease (lipid storage disease)
- Blood cell disorders
- Inflammatory disease
62
What is the origin, insertion, innervation and function of the pyramidalis muscle?
- Origin = front of pubis and pubic symphysis.
- Insertion = linea alba.
- Innervation = anterior ramus of T12.
- Function = tenses the linea alba.
63
What encloses the rectus abdominus and pyramidalis muscles?
An aponeurotic tendinous sheath called the rectus sheath formed from the aponeuroses of the external and internal oblique and transverse abdominus muscles.
64
Which nerves innervate the skin, muscles and parietal peritoneum of the antero-lateral abdominal wall?
T7 to T12 and L1. The anterior rami of these nerves travel posterior to anterior. As they proceed they give off a lateral cutaneous branch and they end as the anterior cutaneous branch.
65
What is the blood supply to the superficial anterolateral abdominal wall?
Superior = musculophrenic artery (terminal branch of the internal thoracic artery).
Inferior = medially by the superficial epigastric artery and laterally by the superficial circumflex iliac artery. Both of these are branches of the femoral artery.
66
What is the blood supply to the deep anterolateral abdominal wall?
Superior = superior epigastric artery (terminal branch of the internal thoracic artery).
Lateral = 10th & 11th intercostal arteries and the subcostal artery.
Inferior = medially by the inferior epigastric artery and laterally by the deep circumflex iliac artery. Both of these are branches of the external iliac artery.
67
Describe the lymphatic drainage in the anterolateral abdominal wall.
- Above the umbilicus = axillary nodes.
- Below the umbilicus = superficial inguinal nodes.
- Deep = parasternal nodes.
68
Which structures travel through the male inguinal canal and spermatic cord?
- Three fascia layers: external spermatic fascia, cremasteric and internal spermatic fascia.
- Three arteries: testicular, cremasteric, deferential.
- Three veins: pampiniform plexus and testicular vein, cremasteric vein, deferential vein.
- Three nerves: genital branch of the genitofemoral nerve, ilioinguinal and autonomic nerves.
- Lymphatics
- Vas deferens
69
Where is the deep inguinal ring situated?
Midway point between the anterior superior iliac spine (ASIS) and the pubic symphysis. It is just above the inguinal ligament and immediately lateral to the inferior epigastric vessels.
70
What is the deep inguinal ring the start of?
It is the start of the tubular evagination of the transversalis fascia that forms one of the coverings of the spermatic cord/the round ligament.
71
What is the superficial inguinal ring, where is it located and attached?
- It is a triangular opening in the aponeurosis of the external oblique muscle.
- It is located superior to the pubic tubercle and lateral to the pubic symphysis. Its base is formed by the inguinal ligament.
- It is attached to the pubic symphysis and pubic tubercle.
72
What is the lesser omentum derived from?
Ventral mesentary
73
Where does the greater omentum attach?
The greater curvature of the stomach and the first part of the duodenum.
It is also adherent to the peritoneum on the superior surface of the transverse colon and the anterior layer of the transverse mesocolon (mesentary of the transverse colon).
74
Which vessels travel through the greater omentum?
Right and left gastro-omental vessels.
75
Where does the lesser omentum attach?
From the lesser curvature of the stomach and the first part of the duodenum to the inferior surface of the liver.
76
What is the lesser omentum divided into?
Medial hepatogastric ligament and lateral hepatoduodenal ligament.
77
Which vessels are found between the layers of the lesser omentum?
Right and left gastric vessels found near the lesser curvature of the stomach.
78
What is the mesentary?
A large, fan-shaped double layer of peritoneum that connects the jujenum and ileum to the posterior abdominal wall.
79
Where does the mesentary start and end?
Start = duodenojujenal junction.
End = ileocecal junction.
80
What are some of the main functions of the liver?
- Produces bile which breaks down fat.
- Converts glucose to glycogen for storage.
- Produces cholesterol.
- Regulates fats and amino acids.
- Stores iron as ferritin which is released as needed to make red blood cells.
- Detoxification.
- Manufactures blood proteins in plasma.
- Immunity.
81
What is a unique ability of the liver?
It is able to regenerate its tissue to a certain extent.
82
What divides the liver into the left and right lobes anteriorly?
The falciform ligament which is a continuation of the peritoneum.
83
What is the round ligament of the liver and what is it also known as?
The embryoligical remnant of the umbilical vein.
Ligamentum teres.
84
What are Couinaud's segments?
They are the 8 functional divisions of the liver.
85
What divides the left and right lobes of the liver posteriorly?
The lesser omentum and the groove where the foetal umbilical vein used to sit (round ligament of the liver).
86
What creates the functional division of the liver?
The gall bladder and the inferior vena cava. This is where the hepatic arteries split into left and right.
87
What is the right lobe of the liver divided into?
Caudate and quadrate.
88
What is the ligamentum venosum?
A structure that runs up alongside the lesser omentum in the posterior liver that used to be the ductus venosus in the foetus (the vein that led from the hepatic portal veins to the hepatic vein and eventually the inferior vena cava).
89
Describe the coronary ligament.
It is a section of peritoneum that runs around the anterior surface of the liver. The far right and left form folds which are called the left and right triangular ligaments.
The area the coronary ligament creates is the bare area where the liver is in direct contact with the diaphragm.
90
What makes up the portal triad?
Common hepatic duct, proper hepatic artery and hepatic portal vein.
91
What is Calot's triangle?
An anatomical area between the portal triad and the gall bladder in the liver. The cystic artery runs directly through.
92
What are the borders of Calot's triangle?
- Medially = common hepatic duct.
- Inferiorly = cystic duct.
- Superiorly = inferior surface of the liver.
93
What are the veins that are part of the hepatic portal system?
- Superior mesenteric vein (draining the midgut).
- Splenic vein (main drainage from the foregut).
- Inferior mesenteric (draining from the hindgut).
- Left gastric & short gastric draining the stomach.
All of these veins drain into the hepatic portal vein.
94
What are two indications of liver disease?
Vomiting blood and blood in the stool due to increased pressure at the porto-systemic anastamoses due to portal hypertension.
95
Describe the biliary tract.
The right and left hepatic ducts come from the liver and fuse to form the common hepatic duct. This then joins the cystic duct which comes from the gall badder to form the common bile duct. The pancreatic duct fuses with the common bile duct to form the hepatopancreatic ampulla (of Vater).
96
What is the sphincter surrounding the hepatopancreatic ampulla called?
The Sphincter of Oddi
97
What is the point where the hepatopancreatic ampulla fuses with the duodenum?
The greater duodenal papilla.
98
What is the lesser duodenal papilla?
The point where the accessory pancreatic duct enters the duodenum.
99
What are the two glands that form the pancreas and what do they secrete?
1. Exocrine secretes digestive enzymes.
| 2. Endocrine secretes insulin and glucagon.
100
What are the two ducts of the pancreas and how do they enter the duodenum?
1. Main pancreatic duct fuses with the common bile duct to form the hepatopancreatic ampulla and enters the duodenum through the greater duodenal papilla.
2. Accessory pancreatic duct enters the duodenum through the lesser duodenal papilla superior to the greater duodenal papilla.
101
What enters the abdomen along with the oesophagus and what do they pass through?
The anterior and posterior vagal trunks.
They pass through the oesophageal hiatus of the diaphragm.
102
What is the blood supply to the oesophagus?
The oesophageal branches from the left gastric artery (from the coeliac trunk) and left inferior phrenic artery (from the abdominal aorta).
103
What is the arterial supply to the stomach?
- Left gastric artery from the celiac trunk and right gastric artery from the hepatic artery proper supply the lesser curvature.
- Right gastro-omental from the gastroduodenal artery and left gastro-omental from the splenic artery supply the greater curvature.
- Short gastric arteries from the splenic artery supply the superior portion of the stomach (fundus).
104
What is the porta hepatis?
The point of entry into the liver for the hepatic arteries and portal vein and the exit point for the hepatic ducts.
105
What is the arterial supply to the liver?
Right and left hepatic arteries that arise from the hepatic artery proper (branch of the common hepatic artery from the celiac trunk).
106
What are the three areas of the gall bladder?
Superior to posterior: neck, body, fundus.
107
What is the arterial supply to the gall bladder?
The cystic artery which is a branch of the right hepatic artery.
108
What are the areas of the pancreas?
Head, unicate process, neck, body, tail.
109
What is the pathway of the pancreatic duct?
It starts at the tail, passes through the body, turns inferiorly when it enters the head and joins the bile duct to form the hepatopancreatic ampulla (ampulla of Vater). This then enters the descending duodenum at the major duodenal papilla.
110
What is the arterial supply to the pancreas?
1) The gastroduodenal artery from the common hepatic artery branches to give the anterior superior pancreaticoduodenal artery and posterior superior pancreaticoduodenal artery. These supply the head.
2) The inferior pancreatic artery from the splenic artery branches to give the dorsal pancreatic artery and the greater pancreatic artery. These supply the neck, body and tail.
3) The inferior pancreaticoduodenal artery from the superior mesenteric artery branches to give the anterior inferior pancreaticoduodenal artery and the posterior inferior pancreaticoduodenal artery. These supply the unicate process.
111
What is the spleen attached to and what passes through these ligaments?
- The greater curvature of the stomach by the gastrosplenic ligament. The short gastric and gastro-omental vessels pass through here.
- The left kidney by the splenorenal ligament. The splenic vessels pass through here.
112
What makes up the foregut?
Stomach, liver, gallbladder, pancreas, and duodenum (up too ampulla of Vater).
113
What makes up the midgut?
Rest of duodenum, jejunum, ileum, cecum, ascending colon and 2/3 of the transverse colon.
114
What makes up the hindgut?
1/3 of the transverse colon, descending colon, sigmoid colon and halfway down the anal canal.
115
What are the proportions of the small intestine?
- Duodenum = 5%
- Jejunum = <40%
- Ileum = <60%
116
How long does it take for food to move through the small intestine?
3-6 hours
117
How does the duodenal cap differ to the rest of the duodenum?
It is ascending and has a smooth wall.
118
What holds up the duodenaljejunal flexure?
The suspensory ligament of Treitz. It is associated with the diaphragm.
119
What passes over the second part of the duodenum?
Transverse mesentary.
120
What crosses over the third part of the duodenum?
The superior mesenteric artey and vein.
121
What are the two hormones that are secreted by the duodenum?
1) Secretin triggers the liver to secrete bile and the pancreas to secrete sodium bicarbonate.
2) Cholecystokinin (CCK) stimulates the release of digestive enzymes in the pancreas and the emptying of bile from the gall bladder.
122
What are the glands found in the submucosa of the jejunum called?
Brunner's glands
123
What are plicae circularis?
Folds found within the small intestine that make up the inner most mucosal layer. They start in the second part of the duodenum, become very thick the jejunum and progressively thinner as you go distally along the ileum.
124
What are the capillaries that supply the small intestine?
Vasa recta
125
What are the main differences between the jejunum and ileum?
- Ileum has more fat in its mesentary.
- Many more arterial arcades are found in the ileum mesentary leading to shorter vasa recta.
- There are islands of lymph tissue called Peyer's patches in the distal ileum which are absent in the jejunum.
126
Where are the lymph nodes found in the small intestine and where do they drain?
They are found within the mesentary and drain to the pre-aortic nodes, specifically superior mesenteric artery nodes (SMA nodes).
127
What are para-aortic lymph nodes?
They are nodes that drain the paired organs of the body. The pre-aortic nodes drain into here.
128
What is the cisterna chyli?
It is a lymphatic sac found in the abdomen along the aorta just inferior to the diaphragm. The para-aortic lymph node drains through here. The contents of the cisterna chyli exits the abdomen through the thoracic duct.
129
What are the functions of the large intestine?
Absorbing water and electrolytes, small amount of digestion by bacteria and movement of faeces to the rectum by mass peristalsis.
130
What is faeces comprised of?
75% water, protein, fat, undigested food, dried digestive juices, cells shed by the intestine and bacteria.
131
What are teniae coli?
A thickening of longitudinal muscle of muscularis externa that is found in three longitudinal strips. They maintain muscle tone causing puckering of the colon which creates haustra.
132
What are epiploic appendages?
They are omental appendices that are fat-filled pouches. Their significance is unknown.
133
What is a pathological feature of the gut that is commonly mistaken for epiploic appendages?
Diverticula. They are swellings of the intestine (mainly large but sometimes small) that if blocked can cause bacterial build-up and irritation. They are most common in the sigmoid colon.
134
Where will a patient with appendicitis feel pain?
Initially in their umbilicus region as the pain is transmitted via the sympathetic nervous system.
When the infection spreads to the peritoneum, it is localised to the area around the appendix which is the right iliac fossa.
135
What is McBurney's point?
Where the base of the appendix is found. If you draw a line from your umbilicus to your anterior inferior iliac spine it is 2/3rds the way down the line.
This is the most tender point for a patient with appendicitis.
136
What are the branches of the superior mesenteric artery?
- Jujenal and ileal
- Ileocolic (supplies the cecum and the appendix)
- Right colic (supplies the ascending colon)
- Middle colic
- Inferior pancreaticoduodenal artery
137
What are the branches of the inferior mesenteric artery?
- Left colic (supplies the distal 1/3 of the transverse colon)
- Sigmoidal
- Superior rectal artery
138
What is the marginal artery?
It is an artery that runs along the internal margin of the large intestine and connects all of the branches of the superior and inferior mesenteric arteries that supply the gut.
139
What vein does the inferior mesenteric vein join with before becoming the hepatic portal vein?
The splenic vein
140
What is the motor nervous supply to the gut?
Vagus to the foregut and midgut.
Pelvic splanchnic nerve to the hindgut.
141
What is the greater splanchnic nerve?
It is a bundle of sympathetic nerve fibres that originate from T5-T9 that synapse in the celiac ganlgion or superior mesenteric ganglion to supply the foregut, midgut and adrenal medulla.
142
What is the lesser splanchnic nerve?
Sympathetic nerve fibres from T10&11 that synapse in the superior mesenteric and aorticorenal ganglia to supply the renal plexus and midgut.
143
What is the least splanchnic nerve?
A collection of sympathetic nerve fibres from T12, L1&2 that synapse at the inferior mesenteric ganglion and passes into the renal plexus.
144
Where is visceral pain referred to by the sympathetic nervous system?
In the midline.
145
What is the parasympathetic innervation of the gut?
Foregut and midgut = vagus nerve.
Hindgut = S2-4 which forms the inferior hypogastric plexus.
146
Why is the rectum a badly named organ?
Because rectus in latin means straight and the rectum is curved.
147
How is the peritoneum distributed in the rectum?
- Upper third = peritoneum on front and sides.
- Middle third = peritoneum in front only.
- Lower third = devoid of peritoneum.
148
What are the borders of the anal triangle?
Superiorly the perineal membrane and two laterally by the sacrotuberous ligament.
149
What is the ischioanal fossa?
It is a fat-filled space lateral to the anal canal which is compressed when the anal canal contains faeces.
150
What is the major pelvic floor muscle?
Levator ani.
151
What is the function of the puborectalis muscle?
It maintains the anorectal angle and supports and aids continence. It pulls the distal end of the rectum forwards.
152
What muscle does the levator ani arise from?
2/3rds up the obturator internus as a tendinous arch which lies on the lateral wall of the pelvis.
153
Where does the pudendal canal sit and what travels through it?
Within the fascia surrounding the obturator interus muscle on the lateral border of the ischioanal fossa.
It contains the internal pudendal artery and vein and the pudendal nerve.
154
What does the inferior rectal nerve arise from and what does it supply?
It arises from the pudendal nerve and supplies the anal canal.
155
What are the functions of the perineal body and the anococcygeal body?
The perineal body (superior) and anococcygeal body (inferior) provide anchorage for the external anal sphincter.
156
What are the rectal valves?
They are folds in the rectum which create kinks. There are two on the left and one on the right.
157
What is the rectal ampulla?
A space below the inferior rectal valve just above the anal canal.
158
Where does the pectinate line in the anal canal lie?
Where the anal columns and valves end. At this point the anal canal stops being hindgut.
159
What is the anal pecten?
It is the area of the anal canal below the pectinate line. Its lower border is the intersphincteric groove/Hilton's white line/anocutaneous line.
160
What does the interspincteric groove/Hilton's white line/anocutaneous line provide a landmark for?
Above the line is the internal anal sphincter and below the line is the external sphincter. There is a slight ridge between the two bundles.
161
What are the four parts of the anal sphincter?
From upper to lower:
- Puborectalis muscle
- Deep
- Superficial
- Subcutaneous
162
What is the arterial supply to the rectum and anal canal?
- Superior rectal artery supplies the rectum and is a branch of the inferior mesenteric artery.
- Middle rectal artery also supplies the rectum and is a branch of the internal iliac artery.
- The inferior rectal artery is a branch of the interior pudendal artery and a supplies the anal canal.
163
What is the venous drainage of the rectum and anal canal?
- Superior rectal vein which drains into the inferior mesenteric artery.
- Middle rectal vein which drains into the internal iliac vein.
- Inferior rectal vein which drains into the internal pudendal vein.
These veins form a plexus around the structures.
164
What is the lymphatic drainage of the rectum and anal canal?
- Upper part of the rectum drains into the pararectal lymph nodes which drain into the inferior mesenteric nodes.
- The lower part of the rectum and anal canal above the pectinate line drain into the internal iliac lymph nodes.
- The anal canal below the pectinate line drains into the superficial inguinal lymph nodes.
165
What are the four parts of the duodenum?
- Superior = most duodenal ulcers occur here. It is also known as the duodenal cap.
- Descending = this part contains the major and minor duodenal papillas.
- Inferior = the longest section.
- Ascending = terminates at the duodenojujenal flexure.
166
What is the arterial supply to the duodenum?
Branches from the gastroduodenal artery, inferior pancreaticoduodenal artery and the superior mesenteric artery supply the duodenum.
167
What is the arterial supply to the jujenum?
Jujenal arteries from the superior mesenteric artery.
168
What is the ileocecal fold?
Two flaps projecting into the large intestine from the ileum. The flaps of the fold come together to form ridges at their end. Musculature from the ileum projects down the flaps to form a sphincter.
169
What is the arterial supply to the ileum?
Ileal arteries from the superior mesenteric artery and an ileal branch from the ileocolic artery (which is itself a branch of the superior mesenteric artery).
170
What is the mesoappendix?
A portion of mesentary that connects the ileum to the appendix which contains the appendicular vessels.
171
What is the arterial supply to the cecum and appendix?
Branches of the ileocolic artery (which is a branch of the superior mesenteric artery) supply the cecum and appendix.
172
What are the right and left paracolic gutters?
Depressions formed between the lateral margins of the ascending and descending colon and the posterolateral abdominal wall. They are spaces through which material can pass from one region of the peritoneal cavity to the other.
173
What is the musculature of the posterior abdominal wall?
- Diaphragm
- Quadratus lumborum
- Psoas major and minor
- Iliacus
174
What is the function of quadratus lumborum?
Flexion and extension of the vertebral column, assists the diaphragm in respiration (keeps 12th rib fixed) and elevates the ilium.
175
What is the origin and insertion of quadratus lumborum?
- Origin = posterior aspect of the iliac bone.
| - Insertion = 12th rib.
176
What muscle is the most powerful flexor of the trunk?
Psoas major
177
How much of the population is missing psoas minor?
~50%
178
What is the nerve supply to the muscle of the posterior abdominal wall?/
- Iliacus = femoral nerve (L2/3).
- Psoas major and quadratus lumborum = lumbar plexus (L1-3)
- Diaphragm = phrenic nerve
179
What is an obvious sign for inflammation and infection of the psoas sheath?
Large bumps/swelling seen above and below the inguinal ligament.
The patient will also be buckled over because the muscle goes into spasm.
180
What vertebrae give rise to the lumbar plexus?
T12-L5
181
What nerves make up the lumbar plexus?
T12 = subcostal nerve
T12& L1 = iliohypogastric & ilioinguinal
L1&2 = genitofemoral
L2&3 = lateral femoral cutaneous
L2, 3, 4 = femoral
L3&4 = acessory obturator
L2, 3, 4 = obturator
L4&5 = lumbosacral
182
What nerve pierces the psoas major?
Genitofemoral nerve
183
At which level does the aorta and inferior vena cava bifurcate?
Aorta = L4
Vena cava = L5
184
What are the arteries that branch directly off of the abdominal aorta to supply the posterior abdominal wall?
- Inferior phrenic branches off at T12 to supply the diaphragm.
- There are four pairs of lumbar arteries that supply the posterior abdominal wall.
- Median sacral artery branches off at the bifurcation of the aorta and supplies the sacrum.
185
What do the external and internal iliac arteries supply?
- External = main supply to the lower limb.
| - Internal = pelvic organs and walls.
186
At what vertebral level do the middle suprarenal, renal and gonadal arteries branch off of the abdominal aorta?
- Middle suprarenal = L1
- Renal = L1/2
- Gonadal = L2
187
What is a triple A?
Abdominal aortic aneurysm.
188
How do they left suprarenal and gonadal veins differ to their right counterparts?
Instead of feeding directly into the inferior vena cava like the right hand veins, they attach to the left renal vein which drains everything into the inferior vena cava.
189
How do the kidneys relate to the vetebrae and the ribs?
The hilum of the kidneys are at the level of L1.
The left kidney spans from rib 11 downwards whereas the right kidney does not reach the 11th rib as it sits lower.
190
What muscles lie behind the kidneys?
- Diaphragm
- Tranverse abdominus
- Quadratus lumborum
- Psoas major
191
What surrounds the kidneys?
From the inside out:
- Perirenal/perinephric fat
- Renal fascia
- Pararenal/paranephric fat
192
What is the minor and major calyx?
The area below the apex of the pyramid of the renal medulla which collects urine draining from the collecting duct. The major calyx is a larger collection area that follows the minor calyx.
193
What is the blood supply and venous drainage to/from the suprarenal glands?
Aterial supply:
- Superior suprarenal artery from the inferior phrenic artery.
- Middle suprarenal artery from the aorta.
- Inferior suprarenal artery from the renal artery.
Venous drainage:
- Suprarenal vein which drains directly into the inferior vena cava on the right side and into the renal vein on the left.
194
Where are interlobular arteries found?
In the cortex of the kidneys running through the renal columns.
195
What are the three natural constriction points of the ureter?
1) Pelvo-ureteric junction
2) Crossing over the external iliac artery
3) Uretero-vesical junction
These are points where kidney stones can get stuck.
196
Where is the referred pain of the ureter? What is the pain called?
Around the T12 level towards the back (where the kidney is). The pain radiates down towards the pelvic area as the ureter contracts.
This is called renal colic.
197
What is the external urethral opening called?
External urethral meatus
198
What are the four parts of the male urethra?
1) Pre-prostatic urethra (where the internal urethral sphincter is - absent in females).
2) Prostatic urethra - receives ejaculatory duct from the prostate. Has a fold in mucosa called urethral crest.
3) Membranous urethra - called because it pierces a sheet of muscle. External urethral sphincter is here.
4) Spongy urethra (sometimes penile urethra).
199
What is the sometimes used fifth part of the male urethra?
The bulbar urethra at the base of the penis.
200
What is the space in the glans of the penis that can affect catheterisation?
The space in the glans is called the navicular fossa which is quite large, but it leads to a blind-ended space called the valvula fossae navicularis which can obstruct the pathway of a catheter.
201
What is the urogenital hiatus?
A gap in the pelvic floor that allows the passage of the urethra and vagina in females.
202
What is found below the pelvic floor?
The deep perineal pouch followed by the perineal membrane followed by the superficial perineal pouch. This is what the membranous part of the urethra pierces.
203
What are the muscles found in the female deep perineal pouch?
- Deep transverse perineal muscle
- Compressor urethrae
- Sphincter urethrovaginalis
- External urethral sphincter
204
What is the innervation to the muscles in the deep perineal pouch?
Pudendal nerve (S2-4)
205
What muscles are found in the male deep perineal pouch?
- External urethral sphincter
| - Deep transverse perineal muscles
206
What are Skene's glands?
They are paraurethral glands found in the walls of the female urethra. They lubricate the walls to allow smooth flow of urine.
207
What is the role of the internal urethral sphincter?
Prevents reflux of semen into the bladder during ejaculation.
208
What is the pelvic course of the ureter in males?
- Crosses over the external iliac artery.
- Over the obliterated umbilical artery (foetal remnant).
- Under the ductus (vas) deferens).
209
What is the pelvic course of the ureter in females?
- Crosses over the external iliac artery.
- Over the obliterated umbilical artery (foetal remnant).
- Under the uterine artery.
210
What is the base of the bladder called?
Trigone - smooth triangular area.
211
What do the three points of the trigone lead to?
Superior two points lead to the points where the ureter enters the bladder called the vesicoureteral junction.
The inferior point leads to the neck of the bladder where the urethra starts.
212
What is the detrusor muscle?
Smooth muscle found in the wall of the bladder that contracts during urination.
213
What is Cowper's gland?
It is the bulbourethral gland which secretes a lubricant into the spongy part of the urethra in males to aid the passage of semen. They lie in the deep perineal pouch.
214
What ligaments support the bladder and urethra?
Females = pubovesical and pubourethral ligaments.
Males = pubovesical and puboprostatic ligaments.
215
What is the blood supply and venous drainage of the bladder?
Aterial = all are vesical arteries which are branches of the internal iliac artery.
Venous = all are vesical veins which drain into the internal iliac vein.
216
What is the lymphatic drainage of the kidney?
Into the left and right lumbar (para-aortic and caval) lymph nodes.
217
What is the lymphatic drainage of the upper ureter?
To kidney lymphatics or lumbar lymph nodes.
218
What is the lymphatic drainage of the middle ureter?
To common iliac lymph nodes.
219
What is the lymphatic drainage of the lower ureter?
To common, external and internal iliac lymph nodes.
220
What is the lymphatic drainage of the pelvic ureter and bladder?
To internal iliac lymph nodes.
221
What is the parasympathetic innervation of the bladder?
Pelvic nerves from S2-4 cause the contraction of the detrusor muscle. Also causes relaxation of the external urethral sphincter.
222
What is the sympathetic innervation of the bladder?
Nerves from T10-L2 form a hypogastric plexus. Sympathetic innervation blocks parasympathetic innervation and causes relaxation of the detrusor muscle. It also tonically stimulates the internal sphincter in males.
223
What is the iliopsoas muscle?
The combination of the psoas major and iliacus muscles as they pass into the thigh and attach to the lesser trochanter of the femur.
224
What is the function of the iliacus muscle?
Flexes the thigh at the hip joint when the trunk is stabilised and flexes the trunk against gravity when the body is supine.
225
What is the structure of the diaphragm?
It consists of a central tendon with muscle fibres branching off of it to form a sheet of muscle. It is attached to the lumbar vertebrae by musculotendinous crura which blend with the anterior longitudinal ligament of the vertebral column.
226
What are the right and left crus of the diaphragm attached to?
- Right = bodies of vertebrae L1-3 and the associated vertebral discs.
- Left = bodies of vertebrae L1&2 and the associated vertebral discs.
227
What is the median arcuate ligament?
It is a ligament that connects the left and right crura of the diaphragm and passes anterior to the aorta.
228
What is the medial arcuate ligament?
A tendinous arch formed by the fascia covering the upper part of the psoas major muscle. It is attached medially to L1&2 and laterally to the transverse process of L1.
229
What is the lateral arcuate ligament?
A tendinous arch lateral to the medial arcuate ligament that is formed by a thickening in the fascia that covers the quadratus lumborum. It is attached medially to the t transverse process of L1 and laterally to rib 12.
230
What structures pass through the diaphragm?
- Aorta & thoracic duct passes posterior through the aortic hiatus.
- Oesophagus, anterior and posterior vagal trunks and the oesophageal branches of the left gastric artery pass through the musculature of the right crus at the level of T10.
- The inferior vena cava and right phrenic nerve pass through the caval opening which is in the central tendon at the level of T8.
- The left phrenic nerve passes through the muscular part of the diaphragm anterior to the central tendon on the left side.
231
What is the blood supply to the superior diaphragm?
Musculophrenic and pericardiacophrenic arteries which are bothbranches of the internal thoracic artery.
Superior phrenic artery which is a branch of the thoracic aorta.
232
What is the blood supply to the inferior diaphragm?
Inferior phrenic arteries which are branches of the abdominal aorta.
233
What is the innervation of the diaphragm?
Phrenic nerves from C3-5 supply main motor and sensory innervation. Additional sensory fibres are supplied to peripheral areas by intercostal nerves.
234
What happens to the renal fascia layers above the adrenal glands?
The anterior and posterior layers fuse and blend with the fascia that covers the diaphragm inferiorly.
235
What happens to the anterior layer of renal fascia medial to the kidneys?
It continues over the vessels in the hilum and fuses with the connective tissue associated with the abdominal aorta and inferior vena cava.
236
What happens to the posterior layer of renal fascia medial to the kidneys?
It fuses with the fascia covering the psoas major muscle.
237
What happens to the anterior and posterior layers of renal fascia inferior to the kidneys?
They enclose the ureters.
238
What is the hilum of the kidney continuous with internally?
The renal sinus.
239
What is the general structure of the kidney?
Outer cortex that encloses renal medullae (renal pyramids). Renal columns separate the renal pyramids.
The apex of each renal pyramid projects inwards towards the renal sinus and the apical projection (renal papilla) is surrounded by a minor calyx.
Several minor calices unite to form a major calyx, and two or three major calices unite to form the renal pelvis which drains directly into the ureters.
240
Why is the right renal artery longer than the left?
Because it must pass posteriorly to the inferior vena cava in order to reach the kidney.
241
What are extrahilar arteries?
Accessory arteries that originate from the lateral aspect of the abdominal aorta and help supply the kidneys.
242
What is the triradiate cartilage?
The cartilage found between the three bones that make up the hip which ossifies around puberty.
243
What are the differences between the pelvic inlet and pelvic outlet?
The pelvic inlet is seen when you look down superiorly and is formed entirely of bone.
The pelvic outlet is seen when you look up posteriorly and is formed of bone and ligaments.
244
What is the relevance of obstetric and diagonal conjugates?
The obstetric conjugate is the shortest pelvic diameter through which the fetal head must pass during birth. The diagonal conjugate is used to calculate this by subtracting 1.25cms from its length.
245
What does android, gynecoid, anthropoid and playpelloid mean in terms of the female pelvis?
They are all names for different shapes of the pelvic inlet that can be seen and relate to childbirth.
- Android = with male features.
- Gynecoid = normal.
- Anthropoid = oval shape with a greater anteroposterior diameter than transverse.
- Platypelloid = inlet with a transverse diameter longer than the anteroposterior diameter, which makes a flat oval.
246
What is the rectovesical pouch?
A part of the peritoneum from the lower third of the rectum to the upper part of the bladder in males.
247
What are the rectouterine and utero-vesical pouches in females?
The rectouterine pouch is an extension of peritoneum between the posterior wall of uterus and the rectum.
The utero-vesical pouch is a second shallower pouch formed from the peritoneum over the uterus and bladder.
248
What is the coccygeus?
A muscle of the pelvic floor located posterior to the levator ani and anterior to the sacrospinous ligament. It pulls the coccyx forward after defecation closing in the back part of the pelvic outlet.
249
What are the three parts of the levator ani?
- Iliococcygeous
- Pubococcygeus
- Puborectalis
250
What is the perineum?
The space between the medial side of two thighs where the external genitalia sit. It is enclosed by the boundaries of the pelvic outlet.
251
How is the perineum divided?
It is a diamond shape split transversely into two triangles. The upper triangle is the urogenital triangle and the lower is the anal triangle.
252
Label the muscles of the pelvic floor in a male and female diagram.
Female = https://teachmeanatomy.info/wp-content/uploads/Muscles-of-the-Pelvic-Floor.jpg
Male = http://www.beyondbasicsphysicaltherapy.com/image/male-pfd-large.jpg
253
What is an episiotomy?
Where you make controlled incisions away from the midline of the vagina to increase the opening for baby delivery. This avoids tearing of the perineal body which is the anchor for the majority of the pelvic floor muscles.
254
What is the perineal membrane?
It is a membrane that lies in the urogenital triangle of the perineum.
255
What is the superficial perineal pouch?
The potential space between the skin and the perineal membrane.
256
What is the deep perineal pouch?
The potential space between the perineal membrane and the lower part of the pelvic diaphragm. Muscles function as a sphincter and stabilise the posterior edge of the perineal membrane.
257
What is the route that sperm takes to leave the testes?
Seminiferous tubules -> rete testis (collecting chamber) -> efferent ductules -> epididymis -> vas deferens -> urethra.
258
What is the processus vaginalis?
It is an outpouching of the parietal peritoneum seen in the embryo.
In males, after the testes descent it closes and becomes the tunica vaginalis.
In females, it forms the canal of Nuck.
259
Why is there such an extensive network of venus plexuses around the testes?
So they can remove excess heat from the area keeping the testes at optimal temperature.
260
What is the contents of the female inguinal canal?
- Round ligament of the uterus
- Genital branch of the genitofemoral nerve
- Ilioinguinal nerve
261
What are the function of leydig and sertoli cells and where are they found?
Leydig = secrete testosterone
Sertoli = support sperm development
They are found in the seminiferous tubules of the testes.
262
What does the prostate secrete?
- Citrate (energy source for sperm motility).
| - Enzymes that break down the semen clot once in the female reproductive tract.
263
What are the functions of seminal vesicles?
They secrete an alkaline fluid with fructose, enzymes and prostaglandins.
264
What is the role of the prostatis sinuses?
This is where the prostatic contribution to the ejaculate leaves the prostate and enters the urethra.
265
What are the two erectile tissues of the penis?
1) Corpus spongiosum. This tissue carries the urethra and forms the bulb of the penis.
2) Corpora cavernosa. This is a paired tissue that forms the crus of the penis. These contain a large amount of coiled arteries which become enlarged during erection.
266
What is the fascia called that surround the corpora cavernosa?
Tunica albuginea
267
What causes a sustained erection?
The tunica albuginea and deep fascia surrounding the erectile tissue restricts venous drainage.
268
What causes ejaculation?
Rhythmic contraction of the bulbospongiosus muscle and opening of the external urethral sphincter which is controlled by branches of the pudendal nerve.
269
What are the lateral vaginal fornices?
They are the superior portions of the vagina, extending into the recesses created by the vaginal portion of cervix. (Google image if unsure).
270
What are the three layers of the uterus?
From outside in:
- Myometrium
- Perimetrium
- Endometrium (this is what grows and is shed during a period).
271
What are the two ducts found in the vagina and what are their functions?
1) Bartholin/greater vestibular glands. They secrete mucus to help lubricate the vagina.
2) Skene/lesser vestibular glands. They secrete fluid to help lubricate the urethral opening.
272
What tissue is the clitorus made up of?
Corpora cavernosa
273
What is the false pelvis?
The wings of the ilium that provides bony support for the lower abdomen and provides attachment for muscles functionally associated with the lower limb.
274
What are the ala?
Wing-like transverse processes on the upper part of the sacrum.
275
What is the promontory?
The anterior edge of the S1 vertebral body.
276
What does the sacral canal terminate as?
Sacral hiatus
277
How does the coccyx articulate with the sacrum?
Via two horns called cornua with articular facets that articulate with the sacral cornua.
278
What two structures do the sacrospinous and sacrotuberous ligaments unite?
Sacrospinous = ischial spine and lower part of sacrum/coccyx.
Sacrotuberous = from posterior inferior iliac spine all the way to the coccyx and attaches to the ischial spine.
279
What are the two muscles of the wall of the pelvis and what are their roles?
- Obturator internus
- Piriformis
They contribute to the lateral walls of the pelvic cavity and allow for lateral rotation of the extended hip joint and abduction of the flexed hip.
280
What separates the pelvic inlet into the greater and lesser sciatic foramens?
The sacrospinous ligament.
281
What is the pelvic diaphragm?
The muscular part of the pelvic floor = levator ani and coccygeus.
282
What happens to the levator ani posterior to the anal aperture?
The three muscles come together as a ligament or raphe called the anococcygeal ligament/body which attaches to the coccyx.
283
What is the the innervation to the levator ani and coccygeus muscle?
Levator ani = braches from S4 and inferior rectal branch of pudendal nerve (S2-4).
Coccygeus = anterior rami of S3 and 4.
284
What does the perineal membrane and adjacent pubic arch provide attachment for?
The roots of the external genitalia and their associated muscles.
285
At what point does the ureter enter the pelvic cavity?
On each side, the ureter crosses the pelvic inlet and enters the pelvic cavity in the area anterior to the birfucation of the common iliac artery.
286
What is the median umbilical ligament and what is its role?
It is an embryological remnant of the urachus that contributes to the formation of the bladder.
It directs the apex of the bladder towards the top of the pubic symphysis and continues up the anterior abdominal wall to the umbilicus.
287
How does the position of the bladder change with age?
At birth the bladder is almost entirely abdominal and descends with age until puberty when it assumes its adult position.
288
What is the mesovarium?
The mesentery that suspends the ovaries.
289
What is the infundibulum?
The ends of the uterine/fallopian tubes rimmed with fimbriae.
290
What is the introitus?
The external opening of the vagina.
291
What separates the posterior surface of the vagina from the rectum?
Rectovaginal septum.
292
What are the motor and sensory innervations of the pudendal nerve?
Motor = skeletal muscles of the perineum and the external urethral and anal sphincters.
Sensory = most skin off the perineum, penis and clitoris.
293
What muscles are found within the superficial perineal pouch?
- Ischiocaverosus
- Bulbospongiosus
- Superficial transverse perineal
294
What are the three branches of the pudendal nerve and what do they innervate?
1) Inferior rectal = external anal sphincter and related regions of levator ani.
2) Perineal nerve = skeletal muscles of superficial and deep pouches.
3) Dorsal nerve of penis and clitoris = sensory innervation to penis and clitoris.
295
What is the major artery of the pelvis and where does it bifurcate?
Internal iliac.
Birfurcates at the superior border of the greater sciatic foramen to form anterior and posterior trunks.
296
What arteries does the anterior trunk of the internal iliac artery give rise to?
- Obturator artery
- Umbilical artery = superior aspect of urinary bladder.
- Inferior vesical artery = inferior aspect of bladder and prostate and seminal vesicles in males.
- Vaginal artery (female)
- Uterine artery (female)
- Middle rectal artery
- Internal pudendal artery = main blood supply to perineum.
- Inferior gluteal artery
297
What arteries does the posterior trunk of the internal iliac artery give rise to?
- Iliolumbar
- Lateral sacral arteries (superior and inferior)
- Superior gluteal
298
What does the iliolumbar artery supply?
It divides into lumbar and iliac branches.
Lumbar = psoas major, quadratus lumborum and posterior abdominal wall.
Iliac = muscles and bone around the iliac fossa.
299
What is the major gonadal artery in females?
Ovarian artery from the abdominal aorta.
