clinical anatomy Flashcards
1
Q
which bones make up the pelvis
A
midline sacrum
coccyx
hip bones (ilium, ischium and pubic bone)
2
Q
functions of the pelvis
A
support of the upper body when standing and sitting
transference of weight from one long pole to two poles
attachment for muscle of locomotion and abdominal wall
protection of pelvic organs, blood and nerve supply etc
attachment for external genitalia
passage for childbirth
3
Q
what are the boundaries of the true pelvis
A
superiorly: pelvic inlet
inferiorly: pelvic outlet
4
Q
what makes up the pelvic inlet
A
sacral promontory of S!
alas of the sacrum
arcuate line of the ilium
pectineal line and pubic crest of the pubic bone
5
Q
what are the borders of the pelvic outlet
A
the tip of the coccyx posteriorly
the inferior margin of the sacrotuberous ligament posterolaterally
the ischial tuberosities laterally
the pubic arch anteriorly
6
Q
which diameter is wider at the pelvic inlet
A
transverse
7
Q
which diameter is wider at the pelvic outlet
A
AP
8
Q
what are the two most important pelvic ligaments
A
sacrospinous
sacrotuberous
9
Q
where does the sacrospinous ligament attach
A
sacrum and ischial spine
10
Q
where does the sacrotuberous ligament attach
A
ischial tuberosity and sacrum
11
Q
features of a male pelvis
A
thick, robust bone narrow, deep pelvis heart-shaped, narrow pelvic inlet small pelvic outlet narrow subpubic angle round obturator foramen narrow greater sciatic notch
12
Q
features of a female pelvis
A
thin, light bone wide, shallow pelvis rounded, wide pelvic inlet large pelvic outlet wide subpubic angle oval obturator foramen 90 degree greater sciatic notch
13
Q
where do pelvic fractures most commonly occur
A
weaker areas pubic rami acetabulum sacroiliac joints alae of the ilium
14
Q
which structures can be damaged in a pelvic fracture
A
iliac vessel and their branches nerves of the lumbosacral plexus autonomic nerve supply lymphatic drainage muscles (pelvic floor, lateral pelvic walls, thigh, gluteal region, abdominal wall) pelvic organs
15
Q
palpable bony landmarks of the ilium
A
ASIS (and inguinal ligament)
iliac crest
PSIS
16
Q
palpable bony landmarks of the ischium
A
ischial tuberosities ischiopubic ramus (deep) ischial spines (internal examination)
17
Q
palpable bony landmarks of the pubic bone
A
pubic symphysis
pubic tubercle
ischiopubic ramus
18
Q
palpable bony landmarks of the sacrum
A
median sacral crest
inferolateral angle
sacral hiatus
sacral promontory (internal examination)
19
Q
what were roots make up the pudendal nerve
A
S2-4
20
Q
what are the modalities of the pudendal nerve
A
sensory, sympathetic and somatic motor to the area and structures of the perineum
21
Q
describe the clinically relevant course of the pudendal nerve (and its implication)
A
the nerve crosses the lateral aspect of the sacrospinous ligament, near its attachment to the ischial spine
injection of the pudendal nerve block near the ischial spine
22
Q
which fontanelle is largest
A
anterior
23
Q
what is the vertex
A
an area of the fatal skull bounded by the anterior and posterior fontanelles and the parietal eminences
24
Q
which fontanelles are covered by the temporals muscle
A
sphenoidal and mastoid fontanelles
25
what is moulding
change of the shape of the skull during labour
| bones pass over each other to allow passage through pelvis
26
what direction should the baby face when entering the pelvic inlet and why
left or right
| the AP diameter of the babies head should line up with the transverse diameter of the pelvis
27
when descending through the pelvic cavity, what movements should the baby's head make
rotate and flex
28
what is the preferred presentation when leaving the pelvic outlet
occipitoanterior
29
why is there a final rotation after the head has been delivered
to allow the shoulders and rest of the body to be delivered
30
how long does the anterior fontanelle remain open
18-24 months
31
when does the posterior fontanelle close
12 months
32
which fetal skull features are palpable in OA presentation
posterior fontanelle
sagittal suture
vertex
anterior fontanelle
33
which foetal skull features are palpable in OP presentation
anterior fontanelle
| orbital margins
34
which fossa lies either side of the anal canal
ischio-anal fossa
35
where does the ischiopubic ramus pass
from the ischial tuberosity to the inferior aspect of the pubic body
36
which muscle passes though the greater sciatic foramen
piriformis (to attach to the greater trochanter)
37
which neuromuscular structures pass through the greater sciatic foramen
sciatic nerve
| gluteal neurovascular bundles
38
what structure separates the deep and superficial perineal pouches
perineal membrane
39
why is the perineal membrane stronger in males
to support the penis
40
where does the perineal membrane attach
ischiopubic rami
| perineal body
41
what is contained in the deep perineal pouch
deep layer of fascia
external urethral sphincter and deep transverse perineal muscle
perineal membrane
42
what is contained in the superficial perineal pouch
external genitalia
43
what is an episiotomy
a deliberate incision of the vagina and pelvic floor to prevent vaginal tears extending towards the rectum
44
where does the episiotomy incision commence
fourchette (small, transverse fold where the labia minora meet)
incision usually goes posterolateral
45
which muscle forms the lateral wall of the ischia-anal fossa
obturator internus
46
what does a pudendal nerve block do
local anaesthesia over dermatomes S2-S4
47
why might the facial nerve be damaged during labour
the fetal skull has no mastoid process, so there is no protection for the facial nerve emerging from the stylomastoid foramen
it can therefore be injured during forceps delivery
48
how can labour cause Klumpke's palsy
if the arm is delivered first, and pulled to speed delivery, it can be moved into forced abduction resulting in traction on the lower trunk of the brachial plexus (C8 and T1)
49
how does Klumpke's palsy present
loss of function of all small muscles in the hand
| clawing of the fingers and sensory loss of the medial aspect of the upper limb
50
how can labour cause Erb's palsy
if the head is derived but the shoulders are stuck, pulling on the head can put traction on the upper trunk of the brachial plexus (C5 and C6)
51
how does Erb's palsy present
adduction and internal rotation of the arm at the shoulder
extension and pronation at the elbow
sensory loss of the lateral aspect of the upper limb
52
why might a women have a temporary foot drop after labour
too much time spent in a lithotomy position can cause neuropraxia of the common fibular nerve
53
what are the primary curvatures of the spine
thorax and sacrum
54
what are the secondary curvatures of the spine
cervical and lumbar
55
where does the adult spinal cord end
L1/L2
56
what anatomical structures does the needle pass through for a spinal anaesthetic
```
ski
SC fat
supraspinous ligament
interspinous ligament
ligamentum flavum
epidural space
dura mater
arachnoid mater in SAS
```
57
complications of spinal anaesthetic
post-spinal headache
| respiratory arrest if reaches the cervical cord
58
what is the epidural space
potential space between the dura mater and the overlying bones and ligaments of the vertebral canal
59
where is the needle inserted for spinal/epidural anaesthetic
L3/4
60
what is the difference in onset between spinal and epidural anaesthetic
```
spinal = fast acting
epidural = slow acting
```
61
nerve supply to the vulva
```
anterior = L1 via ilioinguinal
posterior = S2,3,4 via pudendal
```
62
describe the route of the afferents from the body and fundus of the uterus
travel with sympathetic and reach the spinal cord at T10-L2
63
nerve supply of the vagina
S2,3,4 via pudendal nerve
64
which vertebral levels must be blocked during the first stage of labour
T10-L1
65
which vertebral levels must be blocked int he 2nd stage of labour
S2-S5
66
what position should the patient be in for spinal anaesthetic
head lowered, to curve the lumber spines and increase the IV space
67
surface anatomy of the point of needle insertion for spinal anaesthetic
the plane between the two superior aspects of the iliac crests passes through the spinous process of L4
68
what is the function of the darts muscle
to raise the testis closer to the body in cold conditions
69
what is normal testicular volume
12-25 ml
70
where does the epididymis lie
posterolateral border of the testis
71
should the epididymis be palpable
normally it is difficult to palpate
| if there is an obstruction it may be palpable
72
what are the functions of the testis
spermatogenesis
| secretion of testosterone
73
what is the tunica albuginea
a tough fibrous capsule surrounding the testis
74
what is the tunica vaginalis
a double layer of peritoneum that encloses the testis and epididymis in the scrotum
75
what is a hydrocele
a collection of fluid between the parietal and visceral layers of the tunica vaginalis
76
what are the three parts of the epididymis
head, body and tail
77
where does the epididymis become the vas deferens
at the inferior pole of the testis the tail of the epididymis becomes the vas
78
where does the vas deferens lie in relation to the epididymis
medial on the posterior aspect of the testis
79
describe the course of the vas deferens from the scrotum into the pelvis
ascends within scrotum, through the spermatic cord to enter superficial inguinal ring
though inguinal canal and exits via the deep inguinal ring, lateral to the inferior epigastric artery
passed above and medial to the ureter as it descends into pelvis to meet seminal vesicle to form ejaculatory duct
80
blood supply to the vas
artery to the vas, derived from the superior vesical artery
81
which ducts lie laterally to the urethral crest
many prostatic ducts
| seminal colliculus/veru montanum
82
what is the seminal colliculus
opening of the ejaculatory ducts
83
prostatic bloody supply
branches of the inferior vesical artery
| drained by a plexus of prostatic veins to internal iliac
84
how can tumour spread from the prostate
through an anastomosis between the prostatic venous plexus and valveless veins of the internal vertebral plexus
85
course of sperm
pass through vas, expelled into prostatic urethra along with secretions from seminal vesicles and prostate
propelled along membranous urethra, then penile (spongy) urethra
86
function of seminal vesicles
```
produce semen into ejaculatory duct
supply fructose
secrete prostaglandins (motility)
secrete fibrinogen (clot precursor)
```
87
function of prostate gland
produces alkaline fluid (neutralised vaginal acidity)
| produces clotting enzymes to clot semen within female
88
function of bulbourethral glands
secrete mucus to act as lubricant
89
what structures form the root of the penis proximally and the body of the penis distally
corpus spongiosum
| corpora cavernosum
90
where is the bulb of the penis attached
perineal membrane
91
which muscle surrounds the corpus spongiosum
bulbospongiosus
92
why does the corpus spongiosum have a thin surrounding fascia
to prevent occlusion of the urethra
93
where do the corpora cavernosum attach
ischiopubic rami
94
which muscle surrounds the corpora cavernosum
ischiocavernosus
95
what does the expression 'point and shoot' mean
point
parasympathetic control blocks sympathetic vasoconstriction and allow increased blood flow to form erection
shoot
sympathetic control of muscles involved in ejaculation
96
where do the testicular/ovarian arteries arise
L2 aorta
97
where does lymph from the testis drain
para-aortic nodes
98
why is testicular and ovarian pain referred to the peri-umbilical region
the autonomic nerve supply is derived from T10 and T11, the area that supplies the skin around the umbilicus
99
where does the right testicular (and ovarian) vein drain to
IVC
100
where does the left testicular (and ovarian) vein drain to
left renal vein
101
varicocele is more common in which testis
left
102
what are the 9 abdominal regions
```
epigastrium
left and right hypochondrium
peri-umbilical
left and right lumbar/loin
suprapubic
left and right inguinal
```
103
at what stage gestation does the uterine fundus become palpable
12 weeks
104
the inguinal ligament is formed from the aponeurosis of which muscle
external oblique
105
which hormone allows the female pelvic ligaments to relax during childbirth
relaxin
106
why might the fundal height start to decrease from around 36 weeks gestation
the fetal head starts to descend into the pelvis
107
how does symphysiofundal height relate to gestation
gestation = symphysiofundal height +/- 3 cm
108
which two incisions can be used to access the pelvis
midline vertical
| lower transverse
109
the midline vertical incision is made through which structure
give an advantage and disadvantage of this type of access
linea alba
relatively avascular to rapid, bloodless access is achieved and it can be easily extended
lack of vascularity means healing is difficult and there is increased risk of wound dehiscence and hernia formation
110
what type of surgery is a midline vertical incision more commonly used and why
gynaecological oncology operations
| allows for wide surgical access
111
what are the benefits of a lower transverse incision over a midline incision
better cosmetic outcome
less pain
lower incidence of hernia formation
112
what are the disadvantages of lower transverse incision
access is slower
blood loss is greater
nerve injury is more frequent
113
what type of surgery is a lower transverse incision often used for
c-section
114
what structures are incised during a c-section
```
skin
superficial fascia
rectus sheath
(rectus muscles are separated)
parietal peritoneum
visceral peritoneum
uterus
amniotic sac
```
115
how is risk of damage to the bladder rescued during c-section
the patient is catheterised to reduce the size of the bladder
116
what is the surface marking of the inferior epigastric artery
immediately medial to the deep inguinal ring at the midpoint of the inguinal ligament
the artery passes obliquely up the abdomen towards a point about 2-3 cm lateral to the umbilicus
117
blood supply to the uterus
uterine arteries, branches of the internal iliac
| uterine arteries anastomose with ovarian arteries which tend to supply the fundus
118
what are likely sites of spread of ovarian cancer
GI tract
bladder
liver
spleen
119
which nodes are likely to be involved in lymphatic spread of ovarian cancer
pelvic nodes
| para-aortic nodes
120
at which two sites does lymph from the pelvis converge
para-aortic or lumbar nodes
121
what is the cisterns chyli
convergence of the lumbar lymph trunks that continues as the thoracic duct
122
lymph drainage of rectum
sacral and internal iliac
123
lymph drainage of anal canal
```
internal iliac
(lower canal to superficial inguinal)
```
124
lymph drainage of bladder
internal and external iliac
125
lymph drainage of prostate and proximal urethra
internal iliac
126
lymph drainage of distal, penile urethra, penis and clitoris
superficial inguinal
127
lymph drainage of testis and ovaries
para-aortic
128
lymph drainage of uterine tube, uterine fundus and upper uterine body
para-aortic
129
lymph drainage of lower uterus, cervix and proximal vagina
internal and external iliac and sacral
130
lymph drainage of distal vagina and vulva
superficial inguinal
131
nerve supply of detrusor muscle
parasympathetics derived from the pelvic splanchnic nerves (s2,3,4)
132
nerve supply to urethral smooth muscle
sympathetic nerves derived from the spinal cord at T10 to L2
| descends to bladder via the hypogastric nerves
133
nerve supply of pelvic floor
pudendal nerve S2,3,4
134
what sensation maintains the micturition reflex and which nerve senses it
sensation of urine in the urethra is sensed by the pudendal nerve
135
which surfaces of the bladder are covered by peritoneum
posterior and superior
136
which structures are given the collective name 'vulva'
```
female urogenital triangle structures
mons pubis
labia minora and majora
vestibule
vaginal orifice
orifices of the vestibular glands
clitoris
```
137
what type of epithelium lines the vagina
stratified squamous
138
blood suupply to the vagina and urethra
variable branches from the uterine, vaginal and internal pudendal arteries
139
venous drainage of the urethra and vagina
vaginal plexus, draining to the internal iliac veins
140
structures supporting the cervix and upper vagina
uterosacral, transverse cervical and pubocervical ligaments
141
structures supporting the middle vagina
pelvic fascia
142
structures supporting the lower vagina
levator ani muscles and perineal body
143
'double fold of peritoneum extending laterally from uterus to the pelvic side wall'
broad ligament
144
attachments of the transverse cervical ligaments
cervix and upper to vagina to the lateral walls of the pelvis
145
loss of support of the cervix and upper vagina results in...
uterine and vaginal vault prolapse
146
loss of support of the middle vagina results in...
cystocele and rectocele
147
loss of support of the low vagina results in...
stress urinary incontinence
148
what are the 3 parts of levator ani
puborectalis
pubococcygeus
iliococcygeus
149
what factors contribute to damage to pelvic floor supports
increase intra-abdominal pressure (obesity, chronic cough, constipation, intra-abdominal mass)
pelvic floor muscle trauma and denervation (obstetric trauma, pelvic fracture or surgery, congenital)
connective tissue disorder (age related, oestrogen deficiency)
150
attachments of coccygeus
ischial spine and inferior end of sacrum and coccyx
151
attachments of puborectalis
body of pubis and perineal body
152
attachments of pubococcygeus
pubic bone, tendinous arch of obturator fascia
| vagina, perineal body, rectum and coccyx
153
attachments of iliococcygeus
ischial spine and perineal body/coccyx
154
why is puborectalis involved in maintaining faecal continence
it creates a sling around the rectum, creating an angle between the rectum and canal
155
nerve supply of elevator ani
nerve to levator ani (S4)
| branches of pudendal nerve (S2,3,4)
156
which vessels pass through the obturator foramen
obturator artery
obturator vein
obturator nerve
