anatomy Flashcards
Major Branches of Coeliac trunk
1) Left Gastric
2) Splenic
3) Common Hepatic
Left Gastric artery course
Smallest of the three branches
Ascends across the diaphragm, giving rise to Oesophageal branches.
Then continue anteriorly along the lesser curve of the stomach and then travels backwards and anteriorly to anastomoses with Right Gastric Artery
Splenic Artery Course
Arises inferior to LGA.
Travels left towards spleen, running posterior to the stomach and along the superior margin of the pancreas contained in splenorenal ligament. Splits into 5 branches which support segments of the spleen.
1) Left gastroepiploic - supplies greater curvature of the stomach and greater omental parts Anastomoses with right gastroepiploic artery
2) Short gastrics - fundus of stomach
3) Pancreatic branches for body and tail
Common Hepatic Artery course
Travels right superior to duodenum Two terminal branches 1) Proper Hepatic - Left and Right hepatic - Cystic artery off right hepatic 2) Gatroduodenal - Right gastroepiploic artery - anastomoses with left - Superior pancreaticoduodenal (supplies head of pancreas and duodenal) (anterior AND posterior branches present) - anastomoses with inferior pancreaticoduodenal (off SMA)
First Branch of SMA
Inferior pancreaticoduodenal artery - inferior head of the pancreas, uncinate process and duodenum
Anastamoses with superior pancreaticoduodenal
SMA gives jejunal and ileal artery supply, what is the difference
The jejunal blood supply is characterised by a smaller number of arterial arcades, but longer vasa recta. In contrast, the ileal blood supply is marked by more arterial arcades with shorter vasa recta.
Branches of SMA
comes of L1
1) Inferior pancreaticoduodenal branch
Right: 1) Right (Ascening colon) colic, 2) Ileocolic (appendicular) 3)Middle colic (transverse)
Left: Jejunal, ileal,
Branches of Ileocolic
Superior branch (ascending colon and anastomoses with Mid colic) Inferior branch (1. Ileal branch, caecal branch, appendicular branch, Colic)
Branches of Right colic
Supplies Asceding colon Ascending branch (anastomoses with middle colic artery) Descending branch (anastomoses with superior ileocolic artery)
Middle colic artery supplies…
Proximal 2/3 of Transverse colon
Middle colic artery course
Contained within transverse mesocolon ( intraperitoneal
Splits into left and right
Inferior Mesenteric Artery origin and supply
L3 level towards left
Vasculises hindgut
Branches of IMA
Left Colic
Sigmoid arteries
Superior rectal
Left Colic branches
Left colic artery is first branch of IMA - supplies 1/3 of the transverse colon and descending colon.
Travels anterior to psoas major left ureter and left internal spermatic vessels before deviding to ascending and descending
1) Ascending branch
- Crosses left kidney anteriorly, before entering the mesentary of the transverse collon and upper aspect of descending colon
2) Descending branch - moves inferiorly to supply the lower part of the descending colon. Anastamoses with superior sigmoid artery superior sigmoid artery.
Superior rectal artery
It descends into the pelvis, crossing the left common iliac artery and vein, bifurcates at S3 level
Superior Gluteal Nerve Roots and course
L4, L5, S1.
The superior gluteal nerve leaves the pelvis via the greater sciatic foramen, entering the gluteal region superiorly to the piriformis muscle. Accompanied by SGA and SGV
What are the functions of SGN
Sensory - None
Motor - Gluteus Minimus, G.Medius, TFL
Inferior Gluteal Nerve Roots and course
L5, S1, S2
leaves the pelvis via the greater sciatic foramen, entering the gluteal region inferiorly to the piriformis muscle.
What are the functions of IGN
Motor Functions: Innervates gluteus maximus.
Sensory Functions: None
Sciatic Nerve Roots and course
L4-S3
It emerges inferiorly to the piriformis muscle and descends in an inferolateral direction. nerve moves through the gluteal region, it crosses the posterior surface of the superior gemellus, obturator internus, inferior gemellus and quadratus femoris muscles. It then enters the posterior thigh by passing deep to the long head of the biceps femoris.
Within the posterior thigh, the nerve gives rise to branches to the hamstring muscles and adductor magnus. When the sciatic nerve reaches the apex of the popliteal fossa, it terminates by bifurcating into the tibial and common fibular nerves.
Contents of carotid triangle
Common Carotid External and internal carotid Internal Jugular Vein Vagus Hypoglossal
Cervical Superfical Fascia
Includes Platysma and runs over SCM
Cervical Deep fascial Layer
- Investing
Investing deep fascial layer contains SCM and Trapezius muscles
Carotid sheath contents
1) Common carotid
2) Internal Carotid
3) Vagus
4) Cervical lymph nodes
Prevertebral fascia
Prevertebral encloses the vertebral neck region (including vertebra, spinal cord and assicated muscles)
5 Causes of Thoracic Outlet Syndrome
1) Cervical Ribs
2) Scalene muscle hypertrophy
3) Anomalous muscles
4) Fibrous bands
5) Pancoast tumour
Symptoms of TO syndrome
1) Numbness and pain along medial arm, forearm and 4th 5th digits (brachial plexus compression)
2) Muscle weakness in the hand
3) Swelling of arm
4) Pallor and coldness
8 branches of External Carotid artery
“Some Anatomists Like Freaking Out Poor Medical Students”
1) Superficial Thyroid Artery
2) Acsending Pharyngeal
3) Lingual Artery
4) Facial Artery
5) Occipital Artery
6) Posterior Auricular
7) Maxillary
8) Superfical Temporal
Which CNs pass through Superior Orbital Fissure?
CN 3,4, V1, 6 (occulomotor, trochlear, opthal of trigeminal, Abducens)
Which CNs pass through Foramen Rotundum
V2 (Maxillary)
Which CNs pass through Foramen Ovale
V3 (Mandibular)
Which Structures pass through Foramen Lacerum
Deep petrosal nerve
Meningeal artery branches
Which Structures pass through Foramen Spinosum
Middle meningeal Artery
Which CNs pass through Internal Acoustic Meatus
CN 7, 8 (FACIAL AND VERSTIBULOCOCHOLEAR)
Which CNs pass through Jugular foramen
CN IX, X and XI
Glossopharyngeal, vagus and accessory
Which CNs pass Hypoglossal Canal
Hypoglossal
Which Structures pass through Foramen Magnum
CN XI (accessory)m vertebral and anterior and posterior spinal arteries, and medulla oblongata/spinal cord
What is Le Fort 1 fracture
Fracture superior to the maxillary alveolar process
Spans body of nasal septum
May involve pytergoid plates
What is Le Fort 2 fracture
Posterolateral parts of maxillary sinuses
Infraorbital foramina
Lacrimal or ethmoid bones
What is Le Fort 3 Fracture
Most superior type. Horizontal upper mid face Passes through SOFs Ethmoid and nasal bones Greater wings of sphenoid Frontozygomatic suture line involvement
Describe the course of Sciatic nerve
2cm wide, largest nerve in the body.
L4-S3
Travels from the pelvis in to pelvis via greater sciatic notch.
Travels inferior to piriformis
Enters posterior thigh passing deep to long head of biceps.
Bifurcates at the apex of the popliteal fossa at apex to tibial and common fibular
Alcock canal syndrome? (hint: cyclists)
Pudendal nerve (S2-S4) eNTRAPMENT Supplies sensory and somatic fibres to the external genitalia and surrounding skin and urinary and anal sphincters.
Describe the course of Pudendal nerve
Forms from S2,3,4 and passes inferior aspect of greater sciatic notch, then crosses sacrospinous ligament and re-enters pelvis through the lesser sciatic foramen.
In the pelvis, it accompanies interal pudendal artery and vein, coursing anterosuperiorly through the pudendal canal (Alcock’s canal)
Terminal branches of Pudendal?
1) Inferior rectal
2) Perineal
3) Dorsal nerve of penis/clitoris
What muscles does perineal nerve supply?
Bulbospongiousus
Ischiocavernosus
Levator Ani (Iliococcygeus, pubococcegeus, puborectalis)
Where does the rectum begin and how does it differ?
Rectum begins at level of S3, it is macroscopically disctinct from the colon with an abscence of taenia coli, haustra and omental appendices
Arterial Supply to rectum?
1) Superior Rectal (IMA)
2) Middle Rectal (I.Iliac)
3) Inferior rectal (Interal pudendal)
Venous drainage of rectum?
Think haemorrhoids
Superior, middle and inferior rectal veins
Superior veins empty into the portal venous system
Anastomoses between portal and systemic veins in anal canal
Sympathetic nervous supply of the rectum?
Lumbar Splanchnic
Superior and inferior hypogastric plexuses
Parasympathetic supply of rectum?
S2-4 via Pelvic splanchinc nerves and inferior hypogastric plexxuses
Lympathic drainage of Rectum?
Pararectal lymph noodes which drain into the inferior mesenteric nodes
Lower rectum passes directly to internal iliac lympth nodes
Blood supply above and below Dentate line?
Above= Superior Rectal artery from IMA Below = Inferior rectal - from INTERNAL PUDENDAL
Two Cervix regions?
1) Endocervix - Simple columnar epithelium
2) Ectocervix - distal part of cervix which starts at the external os and projects to vagina- stratified squamous non-keratinised epithelium
Arterial supply of bladder?
Superior Vesical branch of internal iliac
Venous drainage of bladder?
Vesical venous plexus - emplties into internal iliac veins
Bladder reflex Arc
Bladder fills with urine, bladder walls stretch, sensory nerves detect stretch and transmit this information to the spinal cord.
2) Interneurons within the spinal cord relay the signal to the parasympathteic efferent
3) Pelvic nerve acts to contract the detrusor
Reflex bladder level of transection?
Transection above T12
- Afferent signals from the bladder wall are unable to reach the brain, patient will have no awareness of bladder filling, no descending control over external urethral sphincter
- Functioning spinal reflex, so parasympathetic initiates detrouser contraction in response to stretch
- pee constantly
Flaccid bladder -
Transection below T12
Spinal cord transection at this level will damage the parasympathetic outflow
- bladder fills uncontrollably, overflow incontinence
DCML Pathway does?
Fine touch
Propriception
Fibres decussate in Medulla oblongata
Lesion in DCML?
Fibres decussate in Medulla oblongata -
Ipsilateral loss of fine touch, vibration and proprioception
Anteriolateral tract/ Spinothalamic tract does?
Pain, temperature
Lesion in Anteriolateral?
Fibres decussate in Spinal tracts
Contralateral loss of pain and temperature sensation.
Brown Sequard syndrome
Brown-Séquard syndrome refers to a hemisection (one sided lesion) of the spinal cord. This is most often due to traumatic injury, and involves both the anterolateral system and the DCML pathway:
DCML pathway – ipsilateral loss of touch, vibration and proprioception.
Anterolateral system – contralateral loss of pain and temperature sensation.
Lesion in Spinocerebellar tracts?
Spinocerebellar Tracts
Lesions of the spinocerebellar tracts present with an ipsilateral loss of muscle co-ordination.
However, the spinocerebellar pathways are unlikely to be damaged in isolation – there is likely to be additional injury to the descending motor tracts. This will cause muscle weakness or paralysis, and usually masks the loss of muscle co-ordination.
Pyramidal tracts
These tracts originate in the cerebral cortex, carrying motor fibres to the spinal cord and brain stem. They are responsible for the voluntary control of the musculature of the body and face.
Extrapyramidal tracts
tracts originate in the brain stem, carrying motor fibres to the spinal cord. They are responsible for the involuntary and automatic control of all musculature, such as muscle tone, balance, posture and locomotion
What is the autonomic control of the pupil?
Sympathetic fibres originate from T1 and enter sympathetic chain -> Dilation
Parasymp from post ganglionic fibres from the superior cerbical ganglion
Blood supply to the bile duct
bile duct has an axial blood supply which is derived from the hepatic artery and from retroduodenal branches of the gastroduodenal artery.
Axillary nerve?
Terminal branch of the posterior cord of the brachial plexus
Root values C5 and C6
Descends posterior to the axillary artery at the lower border of subscapularis and then passes through quadrangular space with the posterior circumflex humeral vessels
Divides into anterior and posterior branches
Innervates deltoid muscle and small patch of skin over deltoid
Where is Cavernous sinus located?
Lateral aspect of sphenoid body
Where does blood drain from and to cavernous sinus?
receives blood from the superior and inferior ophthalmic veins, the middle superficial cerebral veins, and from another dural venous sinus; the sphenoparietal sinus.
Drains to IJV
Contents of Cavernous sinus
Along with the internal carotid artery, the abducens (VI) nerve crosses the sinus. Several nerves are located within the lateral wall of each sinus; Superior to inferior
oculomotor (III), trochlear (IV), ophthalmic (V1) and maxillary (V2) nerves.
How is facial vein related to cavernous sinus?
facial vein is connected to cavernous sinus via the superior ophthalmic vein. The facial vein is valveless – blood can reverse direction and flow from the facial vein to the cavernous sinus. This provides a potential pathway by which infection of the face can spread to the venous sinuses.
Boundaries of Inguinal canal?
Floor
External oblique aponeurosis
Inguinal ligament
Lacunar ligament
Roof
Internal oblique
Transversus abdominis
Anterior wall
External oblique aponeurosis
Posterior wall
Transversalis fascia
Conjoint tendon
Laterally
Internal ring
Transversalis fascia
Fibres of internal oblique
Medially
External ring
Conjoint tendon
Boundaries of Hasselback Triangle?
Lateral - Inferior epigastric artery
Medially- Rectus Abdominis muscle
Base- Inguinal ligament
Nerves of lumbar plexus - 6 nerves
I Twice Get Laid on Fridays Iliohypogastric Ilioinguinal Genitofemoral Lateral femoral cutaneous Obturator Femoral
All nerves except Gentitofemoral and Obturator emerge lateral to Psoas muscle
Roots of Lumbar plexus nerves?
“2 from 1, 2 from 2, 2 from 3”
2 (Iliohypogastric, Ilioinguinal) from L1
2 (Lateral fem and genitofemoral) from L1,L2
2 (Obturator and Femoral) from L2,3,4
Lymphatic Drainage of Ureters
Upper half - para aortic
Lower half- Common iliac
Musculocutaneous Nerve?
Branch of lateral cord of brachial plexus
Path
It penetrates the coracobrachialis muscle
Passes obliquely between the biceps brachii and the brachialis to the lateral side of the arm
Above the elbow it pierces the deep fascia lateral to the tendon of the biceps brachii
Continues into the forearm as the lateral cutaneous nerve of the forearm
Innervates
Coracobrachialis
Biceps brachii
Brachialis
Structures passing through Foramen Ovale?
"OVALE" Otic Ganglion V3 (Mandibular) Accessory Meningeal artery Lesser petrosal nerve Emissary veins
Movements of the elbow joint
Extension – triceps brachii and anconeus
Flexion – brachialis, biceps brachii, brachioradialis
Extensor Compartment 1
Most lateral
Extensor policis brevis
Abductor policis longus
These tendons form lateral aspect of anatomical snuffbox
Structures passing through the jugular foramen
Glossopharyngeal nerve Vagus nerve Spinal accessory nerve Inferior petrosal sinus Sigmoid sinus Posterior meningeal artery
Foramen Magnum
Medulla oblongata
Vertebral arteries
Spinal roots of the spinal accessory nerve (CN XI)
Internal acoustic meatus
Temporal bone structure
Facial nerve
Vestibulocochlear nerve
Labyrinthine artery
Carotid canal contents
Internal carotid artery and internal carotid nerve plexus
Optic canal
Optic nerve and opthalmic artery
An 18 year old man undergoes a tonsillectomy for attacks of recurrent acute tonsillitis. Whilst in recovery he develops a post operative haemorrhage. Which of the following vessels is the most likely culprit?
arterial supply is from the tonsillar artery, a branch of the facial artery.
external palatine vein lies immediately lateral to the tonsil and if damaged may be a cause of reactionary haemorrhage following tonsillectomy.
Where is the Cavernous sinus located?
The cavernous sinuses are located within the middle cranial fossa, on either side of the sella turcica of the sphenoid bone
Borders of Cavernous sinus?
Anterior – superior orbital fissure.
Posterior – petrous part of the temporal bone.
Medial – body of the sphenoid bone.
Lateral – meningeal layer of the dura mater running from the roof to the floor of the middle cranial fossa.
Roof – meningeal layer of the dura mater that attaches to the anterior and middle clinoid processes of the sphenoid bone.
Floor – endosteal layer of dura mater that overlies the base of the greater wing of the sphenoid bone.
What is special about cavernous sinus?
cavernous sinus is the only site in the body where an artery (internal carotid) passes completely through a venous structure. This is thought to allow for heat exchange between the warm arterial blood and cooler venous circulation.
Contents of Cavernous sinus
Through the sinus
Internal carotid artery
carotid plexus
Abucens (CN 6)
Lateral wall of sinus
CN 3, 4, 5-1, 5-2
