HD anatomy Flashcards
What forms the pelvic brim?
Pubic symphysis
Pectineal line of superior pubic ramus
Arcuate line of ilium
Sacral promonotory
Border of greater sciatic foramen
Superior = anterior sacroiliac joint Anterolaterally = greater sciatic notch Posteromedially = sacrotuberous ligament Inferior = sacrospinous ligament
What passes through the greater sciatic foramen?
Above piriformis
- superior gluteal vessels + nerve
Below piriformis
- sciatic nerve
- inferior gluteal vessels + nerve
- pudendal nerve
- internal pudendal vessels
- posterior femoral cutaneous nerve
Borders of the lesser sciatic foramen
Anterior = ischial tuberosoty Superior = sacrospinous ligament Posterior = sacrotuberous ligament
What passes through the lesser sciatic foramen?
Pudendal nerve
Internal pudendal vessels
Obturator internus
What passes through the obturator foramen?
Obturator artery, vein, nerve
Superior gluteal nerve
L4-S1
Gluteus medius and minimus
Inferior gluteal nerve
L5-S2
Gluteus maximus
Sciatic nerve
L4-S3
Posterior femoral cutaneous nerve
S1-3
Sensation to posterior thigh and leg and some of the perineum
Pudendal nerve
S2-4 Skeletal muscles of the perineum External sphincters Levator ani + coccygeus Sensation to most of the perineum
Blood supply to the rectum
Superior = IMA Middle = IIA Inferior = pudendal
Venous drainage of the rectum
Superior –> HPV
Middle –> IVC
Inferior –> IVC
Posterior division of internal iliac
Iliolumbar
Lateral sacral
Superior gluteal
Anterior division of internal iliac
Umbilical Obturator Inferior vesical Uterine --> vaginal Middle rectal Internal pudendal
Ovarian artery
From abdominal aorta
At L2
Crosses external iliac at pelvic brim
Enters suspensory ligament
Parts of the fallopian tube
Fimbrae
Infundibulum
Ampulla
Isthmus
Supports of the uterus
Anterior = pubocervical ligament Lateral = transverse cardinal ligament Posterior = uterosacral ligament
Lymphatic drainage of the female pelvic organs
Main pelvic viscera –> internal iliac nodes –> lumbar trunks
Ovaries and fallopian tubes –> lateral aortic nodes
What attaches to the perineal body in females?
External anal sphincter Bulbospongiosus Superficial and deep transverse perineal muscles Anterior fibres of levator ani External urinary sphincter
Spinal anaesthesia
Agent injected into CSF at the L3/4 level
Complete anesthesia from the waist down
Caudal epidural block
Catheter allowing anaesthetic to be applied to S2-4 nerve roots
Cervix, vagina, birth canal, pelvic floor and perineum anaesthetised
Lower limbs and uterine body not anaesthetised
Pudendal nerve block
Agent injected around the peripheral nerve
Only inferior vagina and perineum anaesthetised
Layers of the spermatic cord
Internal spermatic fascia
Cremaster muscle and its fascia
External spermatic fascia
Contents of the spermatic cord
Vas deferens + artery Testicular artery + vein Cremasteric artery + vein Genital branch of genitofemoral nerve Sympathetic and visceral afferents Lymphatics
Borders of the inguinal triangle
Inguinal ligament
Inferior epigastric vessels
Lateral border of rectus abdominus
Which side does varicocele occur on?
Left side
What is the main blood supply to the vas deferens?
Superior vesical artery
Alpha blocker
Tamsulosin
5a reductase inhibitor
Finasteride
Muscles of the scrotum
Both supples by genital branch of GF nerve (L1-2)
Dartos
- temperature regulation
- corrugated appearance
- smooth muscle
Cremaster
- skeletal muscle
- between the internal and external spermatic fascia
- arises from the internal oblique musculature
- involved in temperature regulation
What innervates the skin of the scrotum?
Genital branch of GF nerve (L1-2)
Anterior scrotal nerves from ilioinguinal nerve (L1)
Posterior scrotal nerves from perineal nerve from the pudendal nerve (S2-4)
Perineal branches of the posterior femoral cutaenous nerve (S1-3)
Arteries of the penis
Dorsal artery of the penis
Deep arteries of the penis
Bulbourethral artery
3 branches of the pudendal nerve
Inferior rectal - sensation to anal triangle - motor to levator ani and external anal sphincter Perineal - sensation to urogenital triangle - motor to muscles of the deep and superficial perineal pouches Dorsal nerve of penis/clitoris - sensation to glans penis or clitoris
What innervates the internal anal sphincter?
Contraction stimulated by sympathetic fibres in the superior rectal and hypogastric plexuses
Contraction inhibited by parasympathetic innervation
What innervates the external anal sphincter?
Inferior rectal nerve
From pudendal nerve
When does the anterior neuropore close?
Day 25
When does the posterior neuropore close?
Day 27
What happens if the anterior neuropore fails to close?
Anencephaly = baby is born without parts of the brain and skull Encephalopcele = herniation of brain and meminges outside the skull
How can anencephaly be detected?
Ultrasound
Maternal serum alpha fetoprotein will be raised
What happens if the posterior neuropore fails to close?
Spina bfida occulta = mild form where there is a small hair tuft or birth mark
Spina bfida cystica
- meningocele = sac contains meninges and CSF
- myelomeningocele = sac contains meninges, CSF and nerves and spinal cord
What vitamin reduces rates of neural tube defects?
Folic acid
What is formed by pharyngeal arch 1?
Muscles of mastication
Maxilla, mandible, zygomatic, temporal, palatine, vomer
Malleus incus
What is formed by pharyngeal arch 2?
Muscles of facial expression
Styloid process
Lesser horn of hyoid
Stapes
What is formed by pharyngeal arch 3?
Stylopharyngeus
Greater horn of hyoid
What is formed by pharyngeal arch 4?
Muscles of the soft palate
Muscles of the pharynx
Cricothyorid
Laryngeal cartilage
What is formed by pharyngeal arch 5?
Laryngeal muscles
Upper oesophageal muscle
Laryngeal cartilage
What is formed by pharyngeal pouch 1?
Lining of the auditory tube and inner ear
What is formed by pharyngeal pouch 2?
Palatine tonsil
What is formed by pharyngeal pouch 3?
Inferior parathyroid gland
Thymus
What is formed by pharyngeal pouch 4?
Superior parathyroid gland
What is formed by pharyngeal membrane 1?
Tympanic membrane
What forms the thyroid gland?
Endodermal lining of the primitive foregut
Sensation to anterior 2/3 of the tongue
Somatic = V3 lingual nerve Taste = chorda tympani of CN VII
Sensation to posterior 1/3 of the tongue
CN IX
Which arches form the tongue
Anterior 2/3 = 1
Posterior 1/3 = 2-4
What forms the intermaxillary segment and what does it form?
Medial nasal prominence
Maxillary prominence
Forms the philtrum of the lip, palate and upper 4 incisors
How is the nasolacrimal duct formed?
By the fusion of the lateral nasal prominece and the maxillary prominence
What causes a cleft lip?
Failure of fusion of the medial nasal prominence and maxillary prominence
What causes an anterior cleft palate?
Failure of the palatine shelves to fuse with the primary palate
What causes a posterior cleft palate?
Failure of the palatine shelves to fuse with each other
What causes a bifid nose?
Failure of the medial nasal prominences to fuse with each other
What causes an oblique cleft?
Failure of the lateral nasal and maxillary prominences to fuse
What does the heart start to beat?
Day 22
What does the truncus arteriosus form?
Outflow tract
What does the bulbis cordis form?
Smooth parts of the ventricles
What does the primitive ventricle form?
Trabeculated ventricles
What does the primitive atria form?
Trabeculated atria
What does the sinus venosus form?
Coronary sinus and smooth atria
What does the ureteric bud give rise to?
Ureters, renal pelvis, major and minor calyces, collecting ducts
What does the metanephric mesoderm give rise to?
DCT, loop of Henle, PCT, Bowman’s capsule
What is the difference between omphalocele and gastrochisis?
Omphalocele/exomphalos = gut contents herniate into umbilicus so are inside a sac of peritoneum Gastrochisis = herniation of bowel through a weakness in the anterior abdominal wall with no covering of gut contents
What level does the common iliac artery bifurcate?
L5/S1
Which arteries from the internal iliac exit the pelvis?
Superior and inferior gluteal
Internal pudendal
What is left of the umbilical artery?
Superior vesical arteries
Supplies the superior bladder
What does the inferior vesical artery supply?
Only in males
Inferior bladder
Prostate
Seminal vesicle
What does the vaginal artery supply?
Vagina
Inferior bladder
Some of the rectum
GVAs in the lower body
Thorax and abdomen = sympathetic via T5-L2
Pelvic = parasympathetic via S2-4
Where is the pelvic pain line?
Most of the uterus and top of the bladder –> abdomen
Base of the uterus, cervix, vagina, most of the bladder and urethra –> pelvic
Lymphatic drainage of the female pelvis
Uterus –> internal iliac
Ovary –> para-aortic
Vulva –> superficial inguinal nodes (horizontal nodes)
