Anatomy Flashcards
1
Q
What is the main structure of the temporomandibular joint?
A
head of the condylar process sits in the mandibular fossa next to the articular tubercle
2
Q
What are the cavities in the temperomandibular joint for?
A
superior: for translation
inferior: for rotation
3
Q
What nerve supplies the muscles of mastication?
A
mandibular division of the trigeminal nerve so CNV3
4
Q
What structure tenses to move food between the teeth?
A
buccinator
5
Q
Where does CNV3 travel?
A
from the pons, through the foramen oval and to the muscles of mastication and the sensory area (only nerve that comes off the pons)
6
Q
What are the muscles of mastication and where do they attach at either end?
A
- Temporalis: coronoid process of mandible to temporal fossa
- Masseter: angle of mandible to zygomatic arch
- Lateral pterygoid (only one that opens): condyle of mandible to pterygoid plates of sphenoid bone
- Medial pterygoid: angle of mandible to pterygoid plates of sphenoid bone
7
Q
What is the dens?
A
the spiky bit at C2 on a radiograph
8
Q
What is the gingiva?
A
the frontal gums
9
Q
What nerve is the sensation in the mouth supplied by?
A
top half is CN V2 and inferior half is CN V3
10
Q
What is the pathway of the CNV2 nerve?
A
from pons through foramen rotundum to sensory area
11
Q
What are the three salivary glands, where do they secrete to and which nerve supplies them?
A
- Parotid gland: CNIX- side of the face, in front of the ear and secretes into mouth at upper 2nd molar
- Submandibular gland: CNVII- secretes via lingual caruncle
- Sublingual gland: CNVII- secretes via several ducts superiorly
12
Q
What nerve is the posterior 1/3rd of the tongue supplied by?
A
CNIX for both taste and sensation
13
Q
What nerve is the anterior 2/3rds of the tongue supplied by?
A
CNVII for taste
CNV3 for general sensation
14
Q
Which papillae have taste buds?
A
foliate, vallate and fungiform do
filiform doesn’t
15
Q
What is the course of the facial nerve?
A
from the pontomedullary junction, through the temporal bone via the internal acoustic meatus then stylomastoid foramen
16
Q
What does the facial nerve supply?
A
taste to anterior 2/3rd, facial expression and glands on floor of mouth
17
Q
What nerve innervates the tongue muscles?
A
CNXII except (palatoglossus)
18
Q
What is the path of CNXII?
A
from the medulla, through hypoglossal canal to the extrinsic and intrinsic muscle of the tongue
19
Q
What nerves make the gag reflex possible and how does it come about?
A
- mucosa is sensory CNIX at the back of the oral cavity
- motor part of the reflex is CNIX and CNX
- reflex acts to constrict the pharynx
20
Q
What nerves does the anaesthetic act on for an endoscopy act?
A
CNV2, CNV3, CNVII and CNIX
21
Q
Where does CNIX run?
A
glossopharyngeal nerve that runs from the medulla through the jugular foramen to the posterior wall of the oropharynx, parotid gland and to posterior 1/3rd of tongue
22
Q
What are the muscles of the pharynx and what nerves are they supplied by?
A
- three circular muscles that are voluntary and are innervated by CNX and all insert onto midline raphe
- three longitudinal muscles supplied by CNX and CNIX
23
Q
What is involved in the process of swallowing?
A
- Tongue (CNXII) pushes food towards oropharynx (Voluntary)
- Soft palate and larynx elevated (CNIX and CNX for pharyngeal muscles) (Involuntary)
- Circular layer of pharyngeal (CNX) constrictor muscles contract (Involuntary)
- Food bolus enters oesophagus and travels inferiorly by peristalsis (Involuntary)
24
Q
Where does the oesophagus start and where does it go through the diaphragm?
A
C6 begins
T10 crosses diaphragm
25
What heart chamber does the oesophagus run down the back of?
posterior of the left atrium
26
Where are the constrictions in the oesophagus?
cervical, thoracic and diaphragmatic
27
What is the place where the oesophagus becomes the stomach called?
Z-line
28
What areas does the stomach lie in when the patient is supine?
left hypochondrium, epigastric and umbillical regions
29
What layer of the embryo does the gut tube come from?
the endoderm
30
What are the main types of folding to form the gut tube?
lateral and craniocaudal to form the tube within a tube
31
What is the pathological condition where the vitelline duct is affected?
Meckel’s diverticulum which can form cyst or fistula
| 2s: children under 2, males twice as often, 2 inches in length and 2% of population
32
What is the vitelline duct?
the midgut is initially open into the yolk sac but narrows into the vitelline duct which is incorporated into the umbilical cord
33
What are the major blood vessels supplying the foregut, midgut and handout organs?
- Coeliac trunk supplies foregut organs
- Superior mesenteric artery supplies midgut organs
- Inferior mesenteric artery supplies hindgut organs
34
What can a short oesophagus result in?
hiatal hernia
35
What is involved in the stomach formation?
- starts as fusiform dilation
- dorsal wall has rapid growth to form greater curvature and ventral wall growth is slower so there is less curvature
- rotates clockwise 90 degrees LARP (left anterior, right posterior)
- pylorus upwards and fundus downwards.
36
What are mesenteries?
a continuous layer of serous membrane and attach gut tube to anterior and posterior walls of the abdomen
37
What is the omental bursa?
space posterior to the stomach and the rest of the space is the greater sac
38
What does the epiploic foramen do?
connects the lesser and greater sac (gut embryology)
39
How is the greater momentum formed?
dorsal mesentery develops as a double layered sac that fuses to form the the greater omentum which is an apron-like structure
40
How does the duodenum develop?
- rotation of the stomach causes the duodenum to move from the midline to the right side of the abdominal cavity
- dorsal mesentery fuses with peritoneum so parts 2, 3 and the pancreas become retroperitoneal
41
How does the midgut develop?
- cranial and caudal limb develop
- rapid growth so intestinal loops move out through the umbilical cord and lie outside the embryo
- midgut rotates 90 degrees clockwise and herniates through the umbilical cord so the growth continues to form coils
- rotation around the superior mesenteric artery
- comes back into the embryo so the jejunum comes in follwed by the caecum
- caecal bud descends from the right lobe of the liver to right iliac fossa
42
What do the cranial and caudal limbs of the midgut become?
- cranial: forms distal duodenum, jejunum and upper ileum
| - caudal limb: lower ileum, cecum, ascending colon and proximal 2/3rd of transverse colon
43
What is the disease Ompahlocele?
failure of the intestines to return to the body
44
What is the disease Gastroschisis?
protrusion of abdominal content through the wall lateral to the umbilical cord
45
What are the changes in the mesenteries in embryology?
- dorsal mesentery of gut connects to posterior abdominal wall around the axis of the superior mesenteric artery
- ascending and descending colon mesentery fuse with peritoneum and become retroperitoneal
46
What is involved in the formation of the hindgut?
- terminal end is called the cloaca
- membrane that eventually ruptures
- urorectal septum partitions the cloaca into the rectum and the anal canal
- septum and the cloacal membrane fuse at the future site of the perineal body
47
How does the liver develop?
- hepatic diverticulum for the liver and the cranial part becomes the liver and the caudal part becomes the bile duct
- liver then forms hepatic cords which join with umbilical and vitelline veins to give hepatic sinusoids
- endoderm forms the epithelial parts
- septum transversum is derived from the mesoderm
48
How does the pancreas develop?
dorsal and a ventral pancreatic bud which then come together by LARP rotation
49
What is a possible pathological condition with pancreatic development?
pancreas can pathologically encircle duodenum so there can be occlusion of the duodenum
50
What layer is the spleen derived from?
mesoderm
| initially it is haematopoietic
51
What are all the muscles of the anterolateral abdominal wall?
- rectus abdominis
- external oblique (hands in pockets)
- internal oblique (arms hugging)
- transversus abdominis
- parietal peritoneum
- rectus abdominis
52
What is guarding?
when muscles contract at site of injury to guard the abdominal organs (can also occur in peritonitis)
53
What organs are in the foregut?
Oesophagus to mid-duodenum
Liver and gall bladder spleen
Half of the pancreas
54
What organs are in the midgut?
Mid-duodenum to proximal 2/3rds of the transverse colon
| Half of the pancreas
55
What organs are in the hindgut?
Distal 1/3rd of transverse colon to proximal half to anal canal
56
What separates the foregut, midgut and hindgut?
- Foregut and midgut divides half-way between the duodenum
| - Midgut and hindgut divides proximal 2/3rds of transverse colon
57
What lines are used to divide the abdomen into quadrants?
The midline goes from the xiphoid process to the pubic symphysis and the horizontal line goes through the umbilicus to divide the abdomen into quadrants
58
What are the nine regions of the abdomen?
- right and left hypochondrium and epigastric
- right and left lumbar and umbilical
- right and left inguinal and pubic
59
What are the names of the horizontal lines that divide the nine regions?
The horizontal line under the top three regions is the subcostal plane
The horizontal line over the lower three regions is the transtubecular plane
60
What is peritoneum?
thin, transparent and semi-permeable membrane that lines the abdominopelvic cavity and is a continuous sheet
(where it touches the body wall is parietal and where it touches the organs it is visceral)
61
What are the features of retroperitoneal organs and what are some examples of these?
only has visceral peritoneum on the anterior surface so the organ is located in the retroperitoneum
eg pancreas, ascending and descending colon
62
What are the features of intraperitoneal organs and what are some examples of these?
almost completely covered in visceral peritoneum so it not very mobile
eg liver, gallbladder, stomach, parts of small intestine and transverse colon
63
What are the common peritoneal formations?
- Mesentery: connects organ to posterior body wall
- Omentum: double layer of peritoneum that passes from stomach to adjacent organs
- Peritoneal ligaments: double layer of peritoneum connect organs to one another or body wall
64
What are the features of mesentery?
- has connective tissue with blood, lymph vessels, nerve, lymph nodes and fat
- mesentery proper attaches the small intestine to the body wall
- transverse and sigmoid mesocolon and mesoappendix
- gives a high level of mobility
65
What are the greater and lesser omentums?
- The greater omentum is four-layered sheet that hangs like an apron, it attaches the greater curvature of stomach to the transverse colon
- The lesser omentum is a double-layered sheet and runs between lesser curvature of the stomach and duodenum to liver
66
What is the Pringle manoeuvre?
the surgeon places his fingers through the omental foramen and into the lesser omentum to surround the hepatoduodenal ligament which contains the portal triad so the blood flow from the liver to the duodenum will be stopped
67
What do the greater and lesser sacs communicate through?
the omental foramen but the omenta divides the peritoneal cavity into the these two sacs
68
Where does the portal triad lie in relation to the omentum?
in the free edge of the lesser omentum
| within the hepatoduodenal ligament
69
What are the pouches that are present in males and females?
Males have a rectovesical pouch
Females have a vesico-uterine pouch and a recto-uterine pouch
These pouches are effectively draped over the superior aspect of the pelvic organs
70
What is ascites?
a disease where there is a build-up of fluid in the peritoneal cavity which can be caused by cirrhosis or portal hypertension in the liver
71
How is ascites relieved?
by doing a type of paracentesis called an abdominocentesis to drain the ascitic fluid
the needle is placed lateral to the rectus sheath to avoid the inferior epigastric artery which arises from the external iliac
72
What are the most important things to ascertain when finding out about GI pain?
location, character, timing and pain referral pattern
73
What is colicky pain?
‘Colicky pain’ comes and goes in waves because it is with peristalsis
74
What are organs in the abdominal cavity supplied by in terms of nerves?
(including the visceral peritoneum)
are supplied by visceral afferents, the ENS, parasympathetic nerves which speed peristalsis and sympathetic nerves which slow peristalsis down
75
What is the abdominal wall supplied by in terms of nerves?
uses somatic sensory and motor nerves and sympathetic nerve fibres
76
What is the sympathetic outflow to the GI tract?
T5-L2
the nerves do not synapse here
they carry on within the abdominopelvic splanchnic nerves and synapse at the pre-vertebral ganglia
they then go along the arterial branches off the aorta to form periarterial plexuses
77
Why is the nerve characteristic of the adrenal gland different to normal?
synapses in wall of adrenal gland so long presynaptic neurone and short postsynaptic neurone
78
What is the parasympathetic outflow to the GI tract?
craniosacral
CNX (vagus) travels down oesophagus and synapses close to the individual organs
Vagus nerve goes all the way but doesn’t supply hindgut
Hindgut is supplied but the pelvic splanchnic nerves (S2,3,4)
79
Which region does pain in the fore, mid and hindgut come from?
Foregut pain is felt in the epigastric region
Midgut pain is felt in the umbilical region
Hindgut pain is felt in the pubic region
80
What visceral afferents supply each section of the gut?
Foregut is T6-T9
Midgut is T8-T12
Hindgut is T12-L2
81
What are the names of the body wall nerves?
Thoracoabdominal nerves
Subcostal nerve
Iliohypogastric nerve
Ilioinguinal nerve
82
What does appendicitis pain feel like and why?
- dull aching to begin with but the pain then becomes sharper
- appendix is midgut so there is umbilical pain which is around T10
- starts to irritate the parietal peritoneum in the right iliac fossa so the pain moves from being central to being lower right
83
What is bilirubin?
- normal by-product of red blood cells being broken down
- gives stool brown colour
- used to form bile in liver for absorption of fats from small intestine
84
What does the pancreas do?
secretes digestive enzymes into second part of duodenum for food digestion
85
What are the main functions of the liver?
- glycogen storage
- bile secretion
- other metabolic functions
86
What ribs protect the liver?
7-11
87
What are the two recesses surrounding the liver?
- subphrenic recess under the diaphragm and above the liver
- hepatorenal recess (Morison's pouch) is between the right kidney and the liver
(both within the greater sac)
88
What are the lobes of the liver?
- large right lobe
- smaller left lobe
- superior posterior caudate lobe
- posterior inferior quadrate lobe
89
What divides the right and left lobes?
falciform ligament into the round ligament which is a remnant of the umbilical vein
90
Where does the portal triad enter the liver?
at the aorta hepatic at the back of the liver
91
How many hepatic veins are there?
three drain into the IVC
92
What is in the portal triad and where are all the vessels situated?
(all run within the hepatoduodenal ligament)
- hepatic portal vein (most posterior)
- hepatic artery proper
- bile duct (most anterior)
93
What is the blood supply to the liver?
right and left hepatic arteries and branches of the hepatic artery proper
most is from the hepatic portal vein
94
What is included in the hepatic portal system?
- Hepatic portal vein is made up of the splenic veins and the superior mesenteric vein
- Splenic vein drains the foregut
- Superior mesenteric vein drains the midgut
- Inferior mesenteric vein drains blood from the hindgut to the splenic vein
- The inferior vena cava drains the cleaned blood from the hepatic veins into the right atrium
95
What does the spleen look like and what does it do?
- intraperitoneal organ under ribs 9-11
| - breaks down red blood cells into bilirubin
96
What is the coeliac trunk?
- first of three midline branches off the abdominal aorta
| - leaves aorta at T12 and supplies the foregut
97
What does the coeliac trunk trifurcate into?
splenic artery
left gastric artery
common hepatic artery
98
What does the common hepatic artery lead to?
gastroduodenal comes off to become hepatic artery proper (common gives off gas to become proper)
99
What is the blood supply to the stomach?
- right gastric artery anastomoses to the left gastric artery along lesser curvature
- left and right gastro-omental arteries anastomose on the greater curvature
100
What is the structure of the gall bladder?
fundus
body
neck with cystic duct
101
What is the blood supply of the gall bladder?
via the cystic artery which is in the triangle of calot
102
What is the nerve supply to the gall bladder and therefore, where will pain present?
it is a foregut organ so visceral afferents enter spinal cords between T6-T9 and pain will present in the epigastric region
103
Where can gall bladder pain present?
- epigastric region
- can be hypochondriac
- possible referral to right shoulder due to diaphragm irritation
104
What is the name for the surgical removal of the gall bladder?
cholecystectomy
105
Where is the duodenum located?
it is part retroperitoneal and part intraperitoneal
superior = intra
rest = retro
106
What are the parts of the duodenum?
- superior (duodenal cap)
- descending
- horizontal
- ascending
ends at duodenojejunal flexure
107
What is the pyloric sphincter supplied by?
smooth muscle supplied by autonomic nerves with sympathetic causing contraction and parasympathetic relaxation
108
Where does the superior mesenteric artery come off the aorta?
L1 vertebral level posterior to the neck of the pancreas, same level as the pyloric sphincter and the neck of the pancreas
109
When does the superior mesenteric artery become intraperitoneal?
when it comes behind the pancreas and moves in front
110
What forms the biliary tree?
right and left hepatic ducts uniting to form the common hepatic duct which then unites with the cystic duct to form the bile duct or common bile duct
111
What type of valve is in the cystic duct?
spiral
112
What are the papillae of the pancreas?
each bud of the pancreas has a papillae to drain so the minor and major duodenal papilla
113
What forms the ampulla of vater?
main pancreatic duct and the common bile duct join to make the hepatopancreatic ampulla of vater
114
What are the three sphincters in the biliary area?
- bile duct sphincter
- pancreatic duct sphincter
- sphincter of Oddi
115
Where does the pancreas sit?
C curve of the duodenum
116
What are the four parts of the pancreas?
- head (with uncinate process which is the hook that comes off the end of the pancreas)
- neck
- body
- tail
117
What are the main functions of the pancreas?
- exocrine functions (acinar cells releasing pancreatic digestive enzymes into main pancreatic duct)
- endocrine functions (islets of Langerhans secreting insulin and glucagon into the bloodstream)
118
What are the main arteries of the pancreas?
inferior and superior pancreaticoduodenal artery which anastamose
119
What parts of the biliary system can cause jaundice?
- gallstones
- carcinoma at the head of the pancreas
can cause jaundice by causing overspill into the blood (extra-hepatic obstructive causes of jaundice)
120
Where is pancreatic pain felt?
can be in the epigastric or umbilical region as the pancreas is a foregut and a midgut organ and can radiate through to the back region
121
What are the specials sings of acute pancreatitis?
- Grey-Turner’s (right or left flank)
- Cullen’s sign (umbilical)
- vascular haemorrhages of pooled blood in the retroperitoneal space caused by gallstone obstruction leading to reflux of bile and pancreatic juice into the main pancreatic duct
122
Where does the jejunum begin?
duodenaljejunal flexure
123
Where does the ileum end?
ileocaecal junction
124
What are the microscopic features of the jejunum?
- deep red
- thicker and heavier
- more vascular
- less mesenteric fat
- larger tall and closely packed folds
125
What are the microscopic features of the ileum?
- lighter pink
- thinner and lighter
- less vascular
- more mesenteric fat
- low and sparse folds
- there is lymphoid tissue in the ileum
126
What is the arterial and venous supply to the jejunum and ileum?
- arterial blood = superior mesenteric artery via jejunal and ileal arteries
- venous drainage = jejunal and ileal veins to superior mesenteric vein to hepatic portal vein
127
What are the main groups of lymph nodes?
celiac, superior mesenteric, inferior mesenteric and lumbar
128
What is a venous angle?
subclavian joining the internal jugular veins
129
What is unique about the transverse colon?
it has its own mesentery
130
Where does each part of the large intestine sit?
- ascending and descending colon are retroperitoneal
| - caecum, transverse and sigmoid colon are intraperitoneal
131
What do the words supra colic and infra colic mean?
above or below the transverse colon
132
Where are the paracolic gutters?
- between the lateral edges of the ascending and descending colon and the abdominal wall
- part of the greater sac
133
What can collect in the paracolic gutters?
fluid or pus
134
Where do the teniae coli travel?
down the colon on all three sides to join down at the appendix
135
What are the omental appendiges?
hang down off the colon and contain lymphoid tissue
136
What side is higher on the colon?
the splenic flexure on the left of the patient is higher than the hepatic flexure
137
What can pathologically happen to the sigmoid colon?
- can twist to form sigmoid volvulus
- vasculature cut off
- bowel obstruction
- risk of infarction
138
Where exactly does the appendix lie?
McBurney's point:
| 1/3rd of the way between right ASIS and the umbilicus
139
What are the two places that things connect to the caecum?
appendiceal orifice and an ileocaecal orifice (slightly prolapsed ileum into caecum)
140
What level is the bifurcation of the aorta?
L4
141
What level does the coeliac trunk come off the AA?
T12
142
What level does the superior mesenteric artery come off the AA?
L1
143
What level does the inferior mesenteric artery come off the AA?
L3
144
What comes off the superior mesenteric artery?
- Colic arteries, ileocolic branches, appendicular and the inferior pancreaticoduodenal artery (supply caecum, ascending colon and transverse colon)
- Jejunal and ileal branches (supply the small intestine)
- Mesenteric arteries (supply mesentery)
145
What are the differences between the jejunal and ileal mesentery?
- jejunum has longer vasa rectae and larger and fewer arcades
- ileum has short vasa rectae and many small arcades
146
What comes off the inferior mesenteric artery?
colic artery, sigmoid arteries and superior rectal artery (supplies the descending and sigmoid colon)
147
What is the marginal artery of Drummond?
goes all the way round the inside of the colon which is an anastomosis between the SMA and the IMA
148
What is the marginal artery of Drummond important for?
provides collateral circulation and so prevents intestinal ischaemia
149
What is the arterial supply to the rectum?
- IMA branches into the superior rectal artery
| - then the internal iliac artery anastomoses and takes over
150
What are two causes of haematemesis?
- peptic ulcer eroding through the mucosa and filling the stomach with blood
- oesophageal varices rupturing which fills the oesophagus with blood
151
What are the roles of the two venous systems in the body?
- Hepatic portal venous system: drains nutrient-rich blood from GI tract and associated organs and takes it to the liver for cleaning
- Systemic venous system: has venous blood that has been drained from all other organs and moves in into the superior or inferior vena cava
152
What is the venous supply to the foregut, midgut and hindgut?
Foregut: splenic vein
Midgut: superior mesenteric vein
Hindgut: inferior mesenteric vein
153
What are the three places where the systemic and portal venous systems join?
- Skin around umbilicus= anastomosis of epigastric veins and the paraumbilical veins
- Distal end of oesophagus= inferior drains to hepatic portal, superior drains to azygous
- Rectum/anal canal= superior rectal and internal iliac vein
154
What is the venous drainage from the rectum?
- inferior, middle and superior rectal veins
| - drain to the internal iliac vein and the inferior mesenteric vein
155
What can portal hypertension be caused by?
- liver pathology
| - tumour compressing HPV
156
What can portal hypertension lead to?
reversal of blood flow so there are varicose areas eg caput medusae, rectal or oesophageal varices
157
What does faecal continence require?
- rectum
- visceral afferent nerve fibres
- sphincters that can relax and contract
- normal cerebral function
158
What can faecal continence be affected by?
- neurological pathology
- medications
- degeneration of nerves with age
- consistency of stool
159
What are the parts of the pelvic cavity?
- false pelvis (abdominal)
- pelvic cavity (contains pelvic inlet)
- perineum
160
What divides the pelvis from the perineum?
pelvic floor muscles which are part of a reflex and are controlled
161
Where does the rectum start?
S3 at the rectosigmoidal junction
162
Where does the anal canal start?
at the end tip of the coccyx
163
What is on the walls of the rectum?
transverse rectal folds
164
What is the main muscle of the pelvic floor and what is it divided up into?
- levator ani muscle
| - formed of the puborectalis, pubococcygeus and iliococcygeus
165
What does the levator ani muscle do?
- contracts on reflex to coughing or sneezing
- supplied by the pudendal nerves
- relaxes to allow defecation
166
What supplies the pudenal nerve?
S2,3,4 keeps the guts off the floor
167
What are the sympathetic fibres to the pelvis?
- thoracolumbar outflow
- T12-L2 supplies hindgut
- prevertebral ganglion is synapse then moves down on inferior mesenteric artery
168
What is the parasympathetic innervation to the pelvis?
sacral
S2-4
via pelvic splanchnic
synapse in walls of rectum
169
What is the visceral afferent supply to the pelvis?
back to S2-4
| run with parasympathetics (unusual as they usually run with sympathetics)
170
What is the somatic motor supply to the pelvis?
pudendal nerve (S2-4) and nerve to levator ani
171
What are the lymph nodes in the pelvis?
common iliac
internal iliac
external iliac
- drain to the lumbar nodes
172
What are haemorrhoids?
prolapses of rectal venous plexuses which can be internal or external
173
What are haemorrhoids caused by?
raised pressure that can be caused by age, chronic constipation, straining or pregnancy
174
What is the puborectalis muscle?
forms the anorectal sling around the rectum which closes the passageway and is a skeletal muscle to contraction is under voluntary control
175
What are the characteristics of the internal anal sphincter?
- superior 2/3rds
- smooth muscle
- contraction is by sympathetic and inhibited by parasympathetic
- always contracted
176
What are the characteristics of the external anal sphincter?
- skeletal muscle
- inferior 2/3rd
- contraction by pudendal nerve
- voluntarily contracted
177
What is the course and role of the pudenal nerve?
off the sacral plexus
leaves pelvis then enters back into the perineum
supplies the external anal sphincter and the structures of the perineum
178
What is the arterial blood supply to the rectum?
superior rectal artery from IMA
internal iliac artery to middle rectal to infection rectal
179
What is the venous drainage from the rectum?
inferior mesenteric vein above pectinate line (portal)
internal iliac below line (systemic)
180
What is the division of the anal canal?
pectinate line that is the junction between the part formed from endoderm and the part formed from ectoderm
181
What is above and below the pectinate line?
superior is visceral (dull pain)
| inferior is parietal (sharp pain)
182
What is in the ischioanal fossa and what does it do?
- contains fat, vessels and nerves which allow distention of the pelvic floor
- if an abscess forms it won’t affect the structures and can go around the funnel
183
What can happen to the muscles in labour and what is done to stop this?
- fibres of the puborectalis or external anal sphincter can be torn
- muscle can be cut by doctors to stop this happening
184
What are the folds called in the stomach, small and large intestine?
- stomach= rugae
- small intestine= plicae circulares
- large intestine= haustra and teniae coli
185
Where does the greater momentum run from and to?
greater curvature of the stomach and the transverse colon
186
What does the gallbladder do?
stores and concentrated bile
187
What join to form the common bile duct?
common hepatic duct and the cystic duct
188
Where does the aorta, oesophagus and vena cava cross the diaphragm?
aortic hiatus- T12
oesophagus- T10
vena cava- T8
189
What does the coeliac axis (underneath diaphragm) divide into?
left gastric
common hepatic
splenic artery
190
What vertebral level is SMA at?
L1
191
What is the vertebral level of IMA and what does it supply?
L3 and distal 1/3rd of transverse colon downwards
192
What is the parasympathetic supple to the colon?
proximal 2/3rd is vagus
| distal 1/3rd is pelvic splanchnic nerves
193
What level does the aorta bifurcate?
L4
194
What is the portal vein formed from?
the superior mesenteric and splenic vein
