Anatomy and embryology Flashcards
1
Q
What are the bones of the bony pelvis?
A
2 innominate bones
Sacrum
Coccyx
2
Q
Each innominate bone is a fusion between which 3 bones?
A
Ilium
Ischium
Pubis
3
Q
The iliac fossa is the part of the bony pelvis which is for attachment of which muscle?
A
iliacus muscle
4
Q
The iliac crest extends between which two points?
A
ASIS and PSIS
5
Q
The ischiopubic rams is part of which bone(s)?
A
It is a part of both the ischium and the pubis!
6
Q
What type of joint is the hip joint?
A
Synovial joint
7
Q
What type of joint is the pubis symphysis?
A
Secondary cartilaginous
8
Q
The inguinal ligament attaches between which two landmarks?
A
ASIS and the pubic tubercle
9
Q
The ischial spines are palpable on vaginal examination. Where can they be palpated?
A
Palpable about a finger breadth into the vagina at 4 o’clock and 8 o’clock positions
10
Q
What are the two important ligaments of the pelvis and what are their attachments?
A
Sacrospinous ligament
Sacrum and ischial spine
Sacrotuberous ligament
Sacrum and ischial tuberosity
11
Q
What is the function of the ligaments of the pelvis?
A
Ensure the inferior part of the sacrum is not pushed superiorly when weight is suddenly transferred vertically through the vertebral column
(e.g when jumping or in late pregnancy)
12
Q
What are the bones/ bony features that make up the pelvic inlet?
A
Sacral promontory
Ilium
Superior pubic ramus
Pubic symphysis
13
Q
What are the bones/ bony features that make up the pelvic outlet?
A
Pubic symphysis
Ischiopubic ramus
Ischial tuberosities
Sacrotuberous ligaments
Coccyx
14
Q
Which structure forms the inferior part of the pelvic cavity?
A
Levator ani muscle
15
Q
Describe the differences in the bony pelvis in males and females
A
The AP and transverse diameters of the female pelvis are larger at the pelvic inlet and outlet
Subpubic angle (pubic arch) is wider in females
Pelvic cavity is shallower in females
16
Q
What does the term ‘moulding’ mean?
A
Describes the movement of one bone over another to allow the foetal head to pass through the pelvis during labour
17
Q
How should the fetal skull ideally enter the pelvic cavity and why is this?
A
Foetus should enter the cavity facing either to the right or left (transverse direction)
*This is because in the fetal skull the occipitofrontal diameter is longest and in the pelvic inlet the transverse diameter is widest
18
Q
What is meant by the term ‘station’?
A
The distance of the foetal head from the ischial spines
-ve number, means the head is superior
+ve number means the head is inferior
19
Q
In what position should the baby ideally leave the pelvic cavity?
A
OA (occipitoanterior) position
During delivery the fetal head should be in extension
20
Q
Describe how the fetal head changes position in the different stages of labour
A
At the pelvic inlet the fetal head should be transverse
As it descends through the pelvic cavity the fetal head should rotate and should be flexed
At the pelvic outlet the fetal head should ideally lie in the OA direction and extension of the head and neck should occur
After the head is delivered, it is manipulated into a transverse position to allow delivery of the shoulders
21
Q
What is the vertebral level of the PSIS and what structure also ends at this level?
A
S2
Dura ends here
*NB spinal cord ends at L2
22
Q
What group of muscles attaches to the ischial tuberosity?
A
Hamstrings
Back of the thigh
23
Q
What structures pass through the obturator foramen?
A
Obturator nerve
Obturator artery
24
Q
At what vertebral level is the iliac crest?
A
L4
25
What is the soft spot on the head of a newborn called?
Anterior fontanelle
| the spot between the two frontal bones and the parietal bone
26
What structures are contained within the pelvic cavity?
Ovaries
Uterine tubes
Uterus
Superior part of the vagina
27
What structures are contained within the perineum?
```
Inferior part of the vagina
Perineal muscles
Bartholin's glands
Clitoris
Labia
(external genitalia)
```
28
The peritoneum forms which pouches in females?
Vesico-uterine
Recto-uterine (pouch of douglas)
29
Where does excess fluid collect within the peritoneal cavity in women?
Pouch of douglas
| because this is the most inferior part of the peritoneal cavity when in the anatomical position
30
How can fluid be rained from the pouch of douglas?
Culdocentesis
= Drainage via a needle passed through the posterior fornix of the vagina
31
What are the 3 layers of the wall of the uterus from outer to inner?
Perimetrium
Myometrium
Endometrium
32
Which layer of the uterus is shed during the menstrual cycle?
Endometrium
33
Where does implantation usually occur?
Body of the uterus
34
Why might uterine prolapse occur?
Weakness of the strong ligaments, endopelvic fascia and muscles of the pelvic floor
35
What junction must be sampled during a cervical smear?
The squamous columnar junction
| transformation zone
36
The squamous columnar junction involves a transition between which types of epithelium?
Secretory columnar epithelium to squamous epithelium
37
Where does fertilisation usually occur?
Ampulla of the uterine tubes
38
What is Bilateral salpingo-oophrectomy?
Removal of both uterine tubes and ovaries
39
What is unilateral salpingectomy?
Removal of one of the uterine tubes
40
Where is there communication between the genital tract and the peritoneal cavity?
What is the clinical significance of this?
The fimbriae at the end of the uterine tubes open into the peritoneal cavity
Infection could pass between the two areas
- PID can cause peritonitis
- Ectopic pregnancy can develop in the peritoneal cavity
41
Where do the ovaries develop and what is their final position?
Develop on the posterior abdominal wall and move onto the lateral wall of the pelvis by the action of the round ligament of the uterus
42
What nerve supplies the levator ani muscle?
S3,4,5, sacral plexus
"Nerve to levator ani'
43
What kind of muscle is the levator ani?
Skeletal muscle - voluntary control
44
What is the function of levator ani?
Continual support for the pelvic organs by tonic contraction
Maintains faecal and urinary incontinence
Forms the roof of the perineum and the floor of the pelvis
45
Which nerve supplies the perineal muscles?
Pudendal nerve
46
What is the perineal body?
Bundle of tissues into which the perineal muscles attach
47
Where is the focal point which is important for pelvic floor strength?
Perineal body
48
Which gland is responsible for providing lubrication of the female genital tract?
Bartholins gland
| greater vestibular gland
49
Why might a bartholin gland be enlarged?
Infection
50
The bed of the female breast extends from which bony structures/ areas?
Ribs 2-6, lateral border of the sternum, mid-axillary line
51
The bed of the breast lies on what tissues?
Bed of the breast lies on the deep fascia covering the pec major and the serrates anterior
52
Where is the retromammary space?
The space between the breast and underlying tissues (pec major and fascia)
53
Which ligaments are involved in attachment of the female breast?
Suspensory ligaments
54
Where does most lymph from the breast drain to?
Ipsilateral axillary lymph nodes and then to the supraclavicular nodes
NB lymph from the inner breast may drain to the contralateral side
55
Where does lymph form the lower inner breast quadrant drain to?
Abdominal lymph nodes
56
Why might lymphedema occur?
When axillary lymph nodes are removed (e.g for the treatment of breast cancer)
57
Which ligament of the uterus is formed form a double layer of peritoneum?
Broad ligament
58
Which ligament of the uterus is an embryological remnant?
Round ligament
59
Which uterine ligament contains the uterine tubes and the proximal part of the round ligament?
Broad ligament
60
What is the most common position of the uterus?
Anteverted
*cervix is tipped anteriorly relative to the axis of the vagina
61
What is the anti flexed position of the uterus?
Uterus is tipped anteriorly relative to the axis of the cervix
(the mass of the uterus lies over the bladder)
62
What is the retroverted position of the uterus?
Uterus is tipped posteriorly relative to the axis of the vagina
63
What is the retroflexed position of the uterus?
Uterus is tipped posteriorly relative to the axis of the cervix
64
What are the levels of the axillary lymph nodes?
Level I – inferior and lateral to pectoralis minor
Level II – deep to pectoralis minor
Level III – superior and medial to pectoralis minor
65
What is the clinical relevance of the internal thoracic artery supplying the female breast?
Breast cancer can enter the thoracic space and affect the thoracic spine
66
What are the boundaries of the pelvic inlet?
Symphysis pubis
iliopectineal lines
Sacral promontory
67
What are the boundaries of the pelvic outlet?
Pubic arch
Ischial tuberosities
Coccyx
68
Which nerve fibres are involved with structures in the pelvis?
Sympathetic, parasympathetic and visceral afferents
69
Which nerve fibres are involved with structures in the perineum?
Somatic motor and somatic sensory
70
Which nerve fibres transmit pain from the pelvic organs?
Visceral afferents
71
Which nerve transmits pain from the perineum?
Pudendal nerve
72
Describe how pain sensation is relayed differently from superior aspects and inferior aspects of pelvic organs
Superior aspect of pelvic organs / touching the peritoneum
Visceral afferent run alongside SYMPATHETICS
Enter spinal cord between levels T11-L2
Pain is perceived as suprapubic
Inferior aspect of pelvic organs / not touching peritoneum
Visceral afferents run alongside PARASYMPATHETICS
Enter spinal cord at levels S2, S3, S4
73
Where is pain from the inferior aspect of pelvic organs perceived?
Pain perceived in S2, S3, S4 dermatome (perineum)
74
Where is pain from the superior aspect of pelvic organs (touching the peritoneum) perceived?
Pain is perceived as suprapubic
75
Describe pain sensation from structures which cross from the pelvis to the perineum e.g urethra and vagina
Above the levator ani (in pelvis)
- Visceral afferents run alongside parasympathetics and enter the cord at S2,3,4
Below the levator ani (in the perineum)
- Somatic sensory in the pudendal nerve enters the cord at S2,3,4
76
Where do visceral afferents from the uterine tubes, uterus and ovaries enter the spinal cord?
T11-L2
77
Where do visceral afferents from the cervix and superior vagina enter the spinal cord?
S2-S4
78
At what vertebral level does the spinal cord become the cauda equina?
L2
79
At what vertebral level does the subarachnoid space end?
S2
80
Where is anaesthetic injected in spinal and epidural anaesthesia?
L3-L4 region
| anaesthetises the cauda equina
81
Describe sympathetic outflow from the spinal cord
Sympathetics exit with T1-L2 spinal nerves
Travel to sympathetic chains
Pass into all spinal nerves
82
What effect does spinal anaesthetic have on arterioles in the lower limbs?
Hypotension
Blocks sympathetic tone to all arterioles causing skin to be flushed, warm and have reduced sweating
83
The pudendal nerve contains which branches of the sacral plexus?
S2,3,4
84
Why may a pudendal nerve block be used?
To anaesthetise the majority of the perineum
For episiotomy incision, forceps use and perineal stitching post delivery
85
Describe the course of the pudendal nerve
Exits pelvis through the greater sciatic foramen
Passess posterior to the sacrospinous ligament
re-enters pelvis through the lesser sciatic foramen
Travels in the pudendal canal and branches to supply the perineum
86
What bony feature can be used as a landmark when administering pudendal nerve block?
Ischial spine
87
What might occur as a result of pudendal nerve damage during labour?
Weakened pelvic floor and faecal incontinence
88
Which muscles might be torn during labour?
Fibres within the levator ani (puborectalis) or external anal sphincter
89
What is episiotomy?
Surgical incision of the perineum during labor to enlarge the opening for the baby to pass through
90
In which area is the episiotomy incision made?
Ischioanal fossa
91
Why is the incision in episiotomy more often oblique than median?
The median incision has a higher risk of involving the anal sphincter if further tearing occurs
92
What are the different origins of the male and female duct systems?
Male = mesonephric
Female= paramesonephric
93
The testes descend to the scrotum under the control of what?
Gubernaculum
94
What influence does the gonad (testi) have on gonadal and genital duct development?
Mullerian inhibiting substance from sertoli cells suppresses the paramesopnephric ducts
Testosterone stimulates the mesonephric ducts and causes the development of external genitalia
95
How is the broad ligament of the uterus formed?
Fusion of the paramesonephric ducts
96
What influence does the gonad (ovary) have on gonad and genital duct development?
Oestrogen stimulates the paramesonephric ducts and causes development of the external genitalia
97
How does the pelvis differ between males and females?
The subpubic angle is more rounded in females, and more angular in males
The sacral promontory is more anterior in males
98
Which nerves and vessels may be damaged as a result of pelvic trauma?
Iliac artery and vein
Lumbosacral plexus
99
Define what is meant by the perineum?
The space that lies between the elevator ani muscle superiorly and the perineal skin inferiorly
100
Why could a perianal abscess spread readily through the ischioanal fossa?
The Ischianal fossa is mostly made up of fat, with limited blood and lymphatics - this means there is minimal barrier to the spread of infection
101
What clinical procedure in the female pelvis could damage the ureter?
Hysterectomy
102
Where does lymph from the ovaries drain to?
Lumbar lymph nodes
103
Why might uterine prolapse occur?
Weakened pelvic support
Increased abdominal pressure
104
What is a cystocele?
Herniations of the bladder into the vagina
105
What is a rectocele?
Herniations of the rectum into the vagina
106
What is the main function of the fluid secreted by the prostate gland?
Activation of sperm
107
What are the functions of the mucus secreted by the bulbourethral glands?
Lubrication of the female genital tract and neutralisation of the acidic environment of the female tract
108
How can the position of the fatal head be identified during vaginal examination?
Midline suture of the skull
Fontanelles
* Posterior fontanelle is triangular in shape
* Anterior fontanelle is diamond in shape
109
Why can forceps delivery cause Bell's palsy?
The baby doesn't have a mastoid process when it is born, therefore the facial nerve can be damaged causing Bell's palsy
Identified on the baby by a droopy eye and poor sucking
110
Erb's and Klumpke's palsy can both be caused at delivery, how is each caused?
Erb's
*shoulder gets stuck behind the pubic symphysis
Klumpke's
*tugging on the arm during birth
111
What are the differences between Erb's and Klumpke's palsy?
Erb's palsy
- Waiter's tip posture
- C5,6
Klumpke's palsy
- Claw hand
- C8, T1
112
What other names are used to describe a lower segment caesarean section (LSCS) incision?
Suprapubic incision
Pfannestiel incision
Bikini lini incision
113
What are the layers of the anrerolateral abdominal wall from outer to inner?
```
Skin
Fascia
External oblique
Internal oblique
Transversus abdominus
```
114
What is the linea alba?
The midline blending of aponeuroses
115
The fibres of the external obliques run in the same direction as which muscle fibres?
Fibres of the external intercostals
116
The fibres of the internal obliques run in the same direction as which muscle fibres?
Fibres of the internal intercostals
117
Where does the linea alba extend between?
Runs from the xiphoid process to the pubic symphysis
118
What is the risk of not stitching up the rectus sheath of linea alba sufficiently?
Incisional hernias
119
What is the nerve supply to the anterolateral abdominal wall and what are the levels they supply?
Thoraoabdominal nerves (T7-T11)
Subcostal nerves (T12)
Iliohypogastric nerves (L1)
Ilioinguinal nerves (L1)
120
Where do nerves travel in the anterolateral abdominal wall with reference to the different muscle layers?
Nerves travel in the plane between the internal oblique and the transverses abdominis
121
What is the blood supply to the anterior abdominal wall?
Superior epigastric arteries
Inferior epigastric arteries
122
What is the blood supply to the lateral abdominal wall?
Intercostal and subcostal arteries
123
Where is the blood supply to the anterolateral abdominal wall located with reference to the muscle layer?
Blood supply lies posterior to the rectus abdominus muscles
124
The superior epigastric arteries which supply the anterior abdominal wall are a continuation of which artery?
Internal thoracic artery
125
The inferior epigastric arteries which supply the anterior abdominal wall are a continuation of which artery?
External iliac artery
126
The intercostal and subcostal arteries which supply the lateral abdominal wall are continuations of which artery?
Posterior intercostal arteries
127
What are the layers cut through in a LSCS incision?
| opening
```
Skin and fascia
Anterior rectus sheath
Rectus abdominus
Fascia and peritoneum
Uterine wall
Amniotic sac
```
128
What structure needs to be retracted during an LSCS incision?
The bladder
129
What layers are stitched closed after a LSCS incision?
Uterine wall
Rectus sheath
Skin
130
What layers are cut through for a laparotomy?
Skin and fascia
Line alba
Peritoneum
131
What is a laparotomy?
A vertical midline incision into the abdominal cavity
132
Why is healing not as good and the chance of infection increased with midline incisions such as laparotomy?
poor blood supply
| linea alba is an aponeurosis and is avascular
133
What is laparoscopy?
Small incisions made to allow access to the abdominal cavity
134
If a lateral port is required for laparoscopy, which structure must be carefully avoided?
Inferior epigastric artery
135
During laparoscopy, how can the position of the uterus be manipulated to allow for better viewing of the pelvic organs?
By grasping the cervix with forceps inserted through the vagina
136
Where is the inferior epigastric artery located?
Emerges just medial to the deep inguinal ring
Passes superomedially posterior to the rectus abdominus
137
What is an abdominal Vs a vaginal hysterectomy?
An abdominal hysterectomy is the removal of the uterus via an incision made in the abdominal wall
A vaginal hysterectomy is the removal of the uterus via the vagina
138
What kind of incision is made for an abdominal hysterectomy?
Same incision as LSCS
139
During hysterectomy, extreme care must be taken to not damage which structure?
Ureter
140
Describe the relation of the ureter to the uterine artery
The ureter passes inferior to the uterine artery
141
Which duct develops to form the vas deferens in males?
Mesopnephric duct
142
Which duct develops to form the fornix of the vagina in females?
Paramesonephric duct
143
What anatomical landmarks can be used for administration of a pudendal nerve block?
Ischial spines
144
What 3 components make up the pelvic floor?
Pelvic diaphragm
Muscles of the perineal pouches
Perineal membrane
145
What is the deepest layer of the pelvic floor?
Pelvic diaphragm
146
The pelvic diaphragm consists of which two muscles?
Levator ani
Coccygeus
147
The anterior gap between the medial borders of the pelvic diaphragm contains what?
urogenital hiatus
passage for urethra (♂ and ♀)
vagina (♀)
148
What are the 3 parts of the levator ani?
Puborectalis
Pubococcygeus
Iliococcygeus
149
What nerves innervate the levator ani?
Pudendal nerve and nerve to levator ani
150
When does the elevator ani contract and relax?
Tonically contracted
Relaxes to allow urination and defecation
151
What additional support is there for the pelvic organs other than the levator ani?
Endo-pelvic fascia
Pelvic ligaments
152
Describe the location of the deep perineal pouch
Inferior to the levator ani and superior to the perineal membrane
153
What structures are contained within the deep perineal pouch?
Contains part of the urethra
Vagina in females
Bulbourethral glands in male
Neurovascular bundle for penis/clitoris, extensions of the ischioanal fat pads and muscles
154
What is the location and attachments of the perineal membrane?
Superficial to the deep perineal pouch
Attaches laterally to the pubic arch
Closes the urogenital triangle
155
The perineal membrane has openings for what structures?
Urethra
Vagina in females
156
What structure provides the last passive support for the pelvic organs
Perineal membrane and perineal body
157
Which structures are involved in maintaining *urinary continence?
External urethral sphincter
Compressor urethrae
Levator ani
158
Which structure is involved in maintaining *faecal continence? How does it do this?
Puborectalis
Tonic contraction of puborectalis bends the anorectum anteriorly
Active contraction maintains continence after rectal filling
159
Where us the superficial perineal pouch located?
Below the perineal membrane
160
What muscle covers the bulb of the penis in males and contracts to stimulate ejaculation?
Bublospongiosus
161
What muscle covers the vestibular bulb in females?
Bulbospongiosus
162
What are the two main muscles associated with the superficial perineal pouch in males and females?
Bulbospongiosus
and
Ischiocavernosus
163
Describe the different types of vaginal prolapse
Herniation of urethra/ bladder/ rectum/ rectouterine pouch
Cystocele/ rectocele/ enterocele
Presents as a lump in the vaginal wall
164
What are the different types of uterine prolapse and how does it present?
1st 2nd or 3rd degree
Dragging sensation, feeling of a 'lump' and urinary incontinence
165
What is sacrospinous fixation used for?
To repair cervical/ vault descent
166
There is risk of damage to which nerves with sacrospinous fixation?
Pudendal and sciatic nerves
167
What is the normal size of an adult testis?
12-25 mls
168
What procedures are performed during LSCS to minimise the risk of damage to the bladder?
Catheterisation (decreases bladder volume)
Incision is made 2cm above the pubic symphysis to avoid the bladder
Retract is used to move the bladder out the way
169
The inferior epigastric artery is a branch of which artery?
External iliac artery
170
Describe what happens during an erection
Parasympathetic control
Penis engorges with blood
Contraction of muscles pushes blood into the penis
Arteries are in the centre, veins are on the outside, so the veins get squished preventing blood from leaving the penis
171
Describe what happens during ejaculation
Sympathetic control
Constriction of blood vessels allow for the passage of semen
172
What is the most suitable female pelvic shape?
gynaecoid pelvis
173
What is the anthropoid pelvic shape?
Oval shaped inlet with large AP diameter and smaller transverse diameter
174
What is the android pelvic shape?
Triangular/ heart-shaped inlet
175
What lies deep too the tendinous arch of the levator ani?
The ishioanal fossa
176
From which vessel do the majority of the arteries of the pelvis and perineum arise from?
Internal iliac artery
177
Which vessel does the gonadal artery arise from?
L2 abdominal aorta
178
Which vessel does the superior rectal artery arise from?
It is a continuation of the inferior mesenteric artery
179
The medial umbilical ligament (fold) is the remnant of which structure?
Umbilical artery
180
The inferior vesical artery is only present in males. Which vessel is it replaced by in females?
Vaginal artery
181
The median umbilical fold (NB different to the medial umbilical fold) is the remnant of which structure?
The urachus
182
The lateral umbilical fold is the remnant of what?
Internal iliac artery of the fetus
183
Most of the arteries to the male perineum come from the internal pudendal artery. The anterior scrotal artery is an exception to this - it is a branch of which artery?
External iliac artery
184
Blood supply to the ovary comes from an anastomosis of which two vessels?
Ovarian artery and the uterine artery
185
Sacral veins are valveless. What is the significance of this?
Spread of infection and metastases
186
Describe the venous drainage of the pelvis
Mainly to the internal iliac vein
Some drainage via the superior rectal vein into the hepatic portal system
Some drainage via the lateral sacral veins into the internal vertebral venous plexus
187
What are the nerve roots of the obturator nerve?
L2,3,4
188
Superficial pelvic viscera drain to which lymph nodes?
External iliac nodes
189
Inferior pelvic viscera drain to which lymph nodes?
Internal iliac nodes
190
Superficial perineum drains to which lymph nodes?
Superficial inguinal nodes
