Is attached to the posterosuperior medial quadrant of the sclera

Arises from the maxilla on the floor of the orbit, near the anterior margin

Is attached to the posterosuperior medial quadrant of the sclera

Is supplied by the abducent nerve (CN VI)

Is supplied by the posterior ciliary artery

The cricoid cartilage

Articulates with the thyroid cartilage via fibrocartilage joints

Is an incomplete cartilaginous ring

Projects anteriorly as a quadrangular flat part

Provides attachment for anterior cricoarytenoid muscle

Articulates superiorly with the inferior horn of the thyroid cartilage

Its major role is for phonation

Continues with the trachea at C6

Its major role is for phonation

All the muscles are supplied by the receurrent laryngeal nerve

Blood supply is from the inferior thyroid artery

Extends from the base of the skull to the bifurcation of common carotid

Contains the stylohyoid ligament

Contains only three cranial nerves

The radial nerve gives rise to all the following except the:

posterior cutaneous nerve of the arm

lower lateral cutaneous nerve of the arm

posterior cutaneous nerve of the forearm

medial cutaneous nerve of the arm

supplies extensors to the elbow

pierces the medial intermuscular septum of the mid arm

supplies extensor carpi ulnaris

runs on the lateral side of the radial artery in the forearm

occupies the length of the spiral groove

is the largest branch of the brachial plexus

occupies the length of the spiral groove

damage causes inability to extend the wrist and the interphalangeal joints

damage causes sensory loss to the palm

arises from the lateral cord of the brachial plexus

Regarding the vertebrae

The ligamentum flavum joins borders of adjacent spinous processes

Spinal nerves emerge through foramina between the vertebral laminae

The anterior longitudinal ligament extends from the anterior tubercle of the atlas to the upper part of the lumbar spine

Articular processes are joined to adjacent vertebrae by synovial joints

The ligamentum flavum joins borders of adjacent spinous processes

A typical thoracic vertebra has foramina in the transverse processes

When performing a lumbar puncture the spinal needle should not pass through the

Posterior longitudinal ligament

Regarding the pericardium:

strong sternopericardial ligaments connect the fibrous pericardium to the sternum

the transverse sinus separates the four pulmonary veins

the parietal layer of the serous pericardium has no nerve supply

the fibrous pericardium is fused with the IVC

the fibrous pericardium is supplied by the phrenic nerve

strong sternopericardial ligaments connect the fibrous pericardium to the sternum

The alar ligaments connect the

Adjacent vertebral bodies posteriorly

Bodies of the axis to foramen magnum

Adjacent vertebral bodies posteriorly

Tips of adjacent spinous processes

All the following are boundaries of the named triangle except:

Mandible and submental triangle

Mandible and digastric triangle

Sternocleidomastoid and carotid triangle

Sternocleidomastoid and anterior triangle

A fracture through the roof of the maxillary sinus might result in sensory loss to the

Skin overlying the zygomatic bone

Upper incisors and canine teeth

Skin overlying the zygomatic bone

supplies the gut from the entrance of the bile duct to the splenic flexure of the colon

gives rise to the inferior pancreaticoduodenal artery

is the 1st branch of the abdominal aorta

arises from the aorta at the level of L2

supplies the lower part of the oesophagus

Which is true of the thoracic sympathetic trunk

Passes into the abdomen behind lateral arcuate ligament

Greater splanchnic nerve comes from 3rd to 7th cervical ganglia

1st thoracic ganglion often fuses with the inferior cervical ganglion

crosses 1st rib lateral to the superior intercostals artery

gives fibres to the oesophageal plexus

Regarding the sympathetic nervous system:

each cervical ganglion gives off one ramus communicans

every spinal nerve receives a white ramus communican

efferent post ganglionic fibres are myelinated

afferent sympathetic fibres synapse in the sympathetic trunk

preganglionic cell bodies lie within the lateral horn of the T1-L2 spinal segments

each cervical ganglion gives off one ramus communicans

Which of the following has some nerve supply from the radial nerve?

the lateral cord supplies part of the median nerve

Laceration of the recurrent branch of the median nerve results in paralysis of all the following muscles of the thumb EXCEPT:

deep head of flexor pollicis brevis

superficial head of flexor pollicis brevis

passes in front of the lung root

the right vagus nerve is in contact with the trachea

passes in front of the lung root

the right recurrent laryngeal branch hooks around the right subclavian artery

passes through the vena caval forearm

the right vagus nerve supplies branches to the superficial cardiac plexus

Fourth lumbar nerve root supplies:

flexor accessories (quadratus plantae)

Which is true of the vagus nerves?

Left vagus is held away from the trachea by branches of the aortic arch

Vagal trunks receive fibres from the ipsilateral nerve only

Left vagus crosses the aortic arch superficial to the left superior intercostal vein

Right vagus runs superficial to the azygos vein

The medial cutaneous nerve of the arm:

arises from the dorsal cord of the brachial plexus

pierces the deep fascia adjacent to the tendon of biceps

has communications with the circumflex nerve

Regarding lymph nodes, the lateral side of the arm and forearm is drained initially to the:

the lateral cord supplies part of the median nerve

The posterior cutaneous nerve of the thigh:

travels most of its course superficial to the fascia lata

innervates a small area on the labia majora

The intermediate cutaneous nerve of the thigh:

is a branch of the obturator nerve

arises independently of the medial cutaneous nerve of the thigh

Regarding the autonomic nervous system, visceral pain is not referred to L3-5 and S1 because:

there are no sympathetic ganglia associated with theses spinal segments

there are no visceral afferents related to these lumbar splanchnic nerves

there are no white rami communicans to these spinal nerves

there are no sympathetic ganglia associated with theses spinal segments

there is no sympathetic efferent supply to these spinal nerves

there are no grey rami communicans associated with the autonomic ganglia of L3-S1 spinal nerves

Regarding the femoral vein

It receives the great saphenous vein on its anterolateral surface

It drains into the internal iliac vein

It lies lateral to the femoral artery within the femoral sheath

It enters the inferior part of the femoral triangle posterior to the femoral artery

Holding a heavy hammer in your hand involves:

only the long flexors of the fingers

flexion of wrist to strengthen grip

immobilisation of the shoulder joint to strengthen grip

only the long flexors of fingers and opposition of the thumb

requires synergic contraction of wrist extensors

The medial compartment of the thigh:

is supplied mainly by the obturator artery

is limited superiorly by the obturator membrane

is supplied mainly by the obturator artery

Regarding autonomic nervous system, visceral pain is not referred to L3-S1 because:

there are no sympathetic ganglia associated with these spinal segments

there are no visceral afferents related to these lumbar splanchnic nerves

there are no white rami communications to these spinal nerves

there are no sympathetic ganglia associated with these spinal segments

there is no sympathetic efferent supply to these spinal nerves

there are no grey rami communicants associated with the autonomic ganglia of L3-S1 spinal nerves

Which is true of the superior mesenteric artery and its branches?

Right colic artery is the main supply of the caecum

Superior mesenteric artery runs anterior to the 1st part of the duodenum

Right colic artery passes behind the right ureter

Superior mesenteric arises from aorta at level of L2

Main trunk of the superior mesenteric artery ends at the level of Meckel s diverticulum

864 + Mcqs in Anatomy in Uncategorized topics Page 5 McqOptions

201.	The orbit contains all of the following EXCEPT:
A.	Branches of the facial nerve
B.	The optic nerve
C.	The third cranial nerve
D.	A subarachnoid space
E.	The inferior rectus muscle
Answer» B. The optic nerve

Discussion

202.	The inferior oblique
A.	Arises from the maxilla on the floor of the orbit, near the anterior margin
B.	Is attached to the posterosuperior medial quadrant of the sclera
C.	Is supplied by the abducent nerve (CN VI)
D.	Turns the eye upwards and in
E.	Is supplied by the posterior ciliary artery
Answer» B. Is attached to the posterosuperior medial quadrant of the sclera

Discussion

203.	Which muscle abducts the vocal cords?
A.	Transverse arytenoids
B.	Cricothyroid
C.	Lateral cricoarytenoid
D.	Posterior cricoarytenoid
E.	Thyoarytenoid
Answer» E. Thyoarytenoid

Discussion

204.	The cricoid cartilage
A.	Articulates with the thyroid cartilage via fibrocartilage joints
B.	Is an incomplete cartilaginous ring
C.	Projects anteriorly as a quadrangular flat part
D.	Provides attachment for anterior cricoarytenoid muscle
E.	Articulates superiorly with the inferior horn of the thyroid cartilage
Answer» F.

Discussion

205.	Larynx
A.	Continues with the trachea at C6
B.	Its major role is for phonation
C.	Lies behind the thyroid gland
D.	All the muscles are supplied by the receurrent laryngeal nerve
E.	Blood supply is from the inferior thyroid artery
Answer» B. Its major role is for phonation

Discussion

206.	The carotid triangle contains
A.	Subclavia artery
B.	Omohyoid muscle
C.	Occipital artery
D.	Internal laryngeal nerve
E.	Anterior jugular vein
Answer» E. Anterior jugular vein

Discussion

207.	The carotid sheath
A.	Extends from the base of the skull to the bifurcation of common carotid
B.	Contains the stylohyoid ligament
C.	Contains only three cranial nerves
D.	Is attached to the aorta
E.	Contains the sympathetic trunk
Answer» E. Contains the sympathetic trunk

Discussion

208.	The radial nerve gives rise to all the following except the:
A.	posterior cutaneous nerve of the arm
B.	lower lateral cutaneous nerve of the arm
C.	posterior cutaneous nerve of the forearm
D.	posterior interosseous nerve
E.	medial cutaneous nerve of the arm
Answer» F.

Discussion

209.	The radial nerve:
A.	supplies extensors to the elbow
B.	pierces the medial intermuscular septum of the mid arm
C.	supplies extensor carpi ulnaris
D.	runs on the lateral side of the radial artery in the forearm
E.	runs in the cubital fossa
Answer» E. runs in the cubital fossa

Discussion

210.	Radial nerve:
A.	is the largest branch of the brachial plexus
B.	occupies the length of the spiral groove
C.	damage causes inability to extend the wrist and the interphalangeal joints
D.	damage causes sensory loss to the palm
E.	arises from the lateral cord of the brachial plexus
Answer» B. occupies the length of the spiral groove

Discussion

211.	Regarding the vertebrae
A.	Spinal nerves emerge through foramina between the vertebral laminae
B.	The anterior longitudinal ligament extends from the anterior tubercle of the atlas to the upper part of the lumbar spine
C.	Articular processes are joined to adjacent vertebrae by synovial joints
D.	The ligamentum flavum joins borders of adjacent spinous processes
E.	A typical thoracic vertebra has foramina in the transverse processes
Answer» D. The ligamentum flavum joins borders of adjacent spinous processes

Discussion

212.	When performing a lumbar puncture the spinal needle should not pass through the
A.	Ligamentum flavum
B.	Posterior longitudinal ligament
C.	Supraspinous ligament
D.	Inerspinous ligament
E.	Skin
Answer» C. Supraspinous ligament

Discussion

213.	All the following are contents of the posterior triangle EXCEPT:
A.	Accessory nerve
B.	Cervical plexus
C.	Inferior belly of omohyoid
D.	Transverse cervical vessels
E.	Occipital lymph nodes
Answer» F.

Discussion

214.	Regarding the pericardium:
A.	the transverse sinus separates the four pulmonary veins
B.	the parietal layer of the serous pericardium has no nerve supply
C.	the fibrous pericardium is fused with the IVC
D.	the fibrous pericardium is supplied by the phrenic nerve
E.	strong sternopericardial ligaments connect the fibrous pericardium to the sternum
Answer» E. strong sternopericardial ligaments connect the fibrous pericardium to the sternum

Discussion

215.	The alar ligaments connect the
A.	Bodies of the axis to foramen magnum
B.	Dens to foramen magnum
C.	Adjacent vertebral bodies posteriorly
D.	Tips of adjacent spinous processes
E.	Adjacent laminae
Answer» C. Adjacent vertebral bodies posteriorly

Discussion

216.	All the following are boundaries of the named triangle except:
A.	Mandible and submental triangle
B.	Mandible and anterior triangle
C.	Mandible and digastric triangle
D.	Sternocleidomastoid and carotid triangle
E.	Sternocleidomastoid and anterior triangle
Answer» B. Mandible and anterior triangle

Discussion

217.	Which of the following enters into the inferior meatus of the nose?
A.	Frontal sinus
B.	Ethmoidal sinus
C.	Maxillary sinus
D.	Nasolacrimal duct
E.	Auditory tube
Answer» E. Auditory tube

Discussion

218.	A fracture through the roof of the maxillary sinus might result in sensory loss to the
A.	Tympanicmembrane
B.	Lacrimal gland
C.	Upper molar teeth
D.	Upper incisors and canine teeth
E.	Skin overlying the zygomatic bone
Answer» E. Skin overlying the zygomatic bone

Discussion

219.	All the following structures pass through the jugular foramen EXCEPT:
A.	Jugular vein
B.	Glossopharyngeal nerve
C.	Hypoglossal nerve
D.	Accessory nerve
E.	Vagus nerve
Answer» D. Accessory nerve

Discussion

220.	The celiac trunk
A.	supplies the gut from the entrance of the bile duct to the splenic flexure of the colon
B.	gives rise to the inferior pancreaticoduodenal artery
C.	is the 1st branch of the abdominal aorta
D.	arises from the aorta at the level of L2
E.	supplies the lower part of the oesophagus
Answer» F.

Discussion

221.	Which is true of the thoracic sympathetic trunk
A.	Passes into the abdomen behind lateral arcuate ligament
B.	Greater splanchnic nerve comes from 3rd to 7th cervical ganglia
C.	1st thoracic ganglion often fuses with the inferior cervical ganglion
D.	crosses 1st rib lateral to the superior intercostals artery
E.	gives fibres to the oesophageal plexus
Answer» F.

Discussion

222.	Regarding the sympathetic nervous system:
A.	every spinal nerve receives a white ramus communican
B.	efferent post ganglionic fibres are myelinated
C.	afferent sympathetic fibres synapse in the sympathetic trunk
D.	preganglionic cell bodies lie within the lateral horn of the T1-L2 spinal segments
E.	each cervical ganglion gives off one ramus communicans
Answer» E. each cervical ganglion gives off one ramus communicans

Discussion

223.	Which of the following is not a direct attachment of the pectoral girdle to the trunk?
A.	pectoralis minor
B.	pectoralis major
C.	trapezius
D.	serratus anterior
E.	levator scapulae
Answer» C. trapezius

Discussion

224.	Which of the following is a branch of the mandibular nerve
A.	Infraorbital nerve
B.	External nasal nerve
C.	Zygomaticofacial nerve
D.	Auricolotemporal nerve
E.	Zygomaticotemporal nerve
Answer» E. Zygomaticotemporal nerve

Discussion

225.	Which of the following has some nerve supply from the radial nerve?
A.	long head of biceps
B.	coracobrachialis
C.	short head of biceps
D.	brachialis
E.	the lateral cord supplies part of the median nerve
Answer» E. the lateral cord supplies part of the median nerve

Discussion

226.	which of the following is a branch of the maxillary nerve?
A.	Zygomaticotemporal nerve
B.	Zygomaticotemporal nerve
Answer» B. Zygomaticotemporal nerve

Discussion

227.	Laceration of the recurrent branch of the median nerve results in paralysis of all the following muscles of the thumb EXCEPT:
A.	abductor pollicis brevis
B.	deep head of flexor pollicis brevis
C.	opponens pollicis
D.	superficial head of flexor pollicis brevis
E.	ulnar artery
Answer» C. opponens pollicis

Discussion

228.	Which nerve is a branch of the lateral cord of the brachial plexus?
A.	upper subscapular nerve
B.	thoracodorsal nerve
C.	musculocutaneous nerve
D.	ulnar nerve
E.	lower subscapular nerve
Answer» D. ulnar nerve

Discussion

229.	With respect to the sensory innervation of the visceral pericardium, which of the following nerves predominantly provides sensory fibres?
A.	left vagus
B.	left phrenic
C.	left 4th intercostal
D.	all of the above
E.	none of the above
Answer» F.

Discussion

230.	The vagus nerve:
A.	the right vagus nerve is in contact with the trachea
B.	passes in front of the lung root
C.	the right recurrent laryngeal branch hooks around the right subclavian artery
D.	passes through the vena caval forearm
E.	the right vagus nerve supplies branches to the superficial cardiac plexus
Answer» B. passes in front of the lung root

Discussion

231.	Fourth lumbar nerve root supplies:
A.	hip flexors
B.	tibialis anterior
C.	skin on the big toe
D.	flexor longus digitorum
E.	flexor accessories (quadratus plantae)
Answer» C. skin on the big toe

Discussion

232.	Which is true of the vagus nerves?
A.	Left vagus is held away from the trachea by branches of the aortic arch
B.	Run in front of the lung roots
C.	Vagal trunks receive fibres from the ipsilateral nerve only
D.	Left vagus crosses the aortic arch superficial to the left superior intercostal vein
E.	Right vagus runs superficial to the azygos vein
Answer» B. Run in front of the lung roots

Discussion

233.	The medial cutaneous nerve of the arm:
A.	has fibres from C8 and T1
B.	arises from the dorsal cord of the brachial plexus
C.	pierces the deep fascia adjacent to the tendon of biceps
D.	has communications with the circumflex nerve
E.	none of the above
Answer» B. arises from the dorsal cord of the brachial plexus

Discussion

234.	Regarding lymph nodes, the lateral side of the arm and forearm is drained initially to the:
A.	supratrochlear nodes
B.	posterior axillary nodes
C.	infraclavicular nodes
D.	central axillary nodes
E.	the lateral cord supplies part of the median nerve
Answer» D. central axillary nodes

Discussion

235.	The segmental supply to the posterior cutaneous nerve of the thigh is:
A.	S3, 4
B.	L4, 5
C.	S1, 2, 3
D.	L4, 5 and S1
E.	none of the above
Answer» D. L4, 5 and S1

Discussion

236.	The lateral aspect of the thigh has a cutaneous nerve supply derived from:
A.	L2 and 3
B.	L3 and 4
C.	L5, S1 and S2
D.	L4, L5 and S1
E.	S1 and S2
Answer» B. L3 and 4

Discussion

237.	The posterior cutaneous nerve of the thigh:
A.	consists only of S2, 3
B.	travels most of its course superficial to the fascia lata
C.	innervates a small area on the labia majora
D.	emerges above pinforris
E.	none of the above
Answer» D. emerges above pinforris

Discussion

238.	The sole of the foot has a cutaneous nerve supply derived from:
A.	L4, L5, S1 and S2
B.	L5 and S1
C.	L4, L5 and S1
D.	L4 and L5
E.	L5, S1 and S2
Answer» C. L4, L5 and S1

Discussion

239.	The intermediate cutaneous nerve of the thigh:
A.	arises from the sacral plexus
B.	is a branch of the obturator nerve
C.	pierces sartorius
D.	extends beneath the knee
E.	arises independently of the medial cutaneous nerve of the thigh
Answer» D. extends beneath the knee

Discussion

240.	The cutaneous nerve supplying the medial aspect of the calf is:
A.	anterior femoral cutaneous
B.	sural
C.	superficial peroneal
D.	saphenous
E.	posterior femoral cutaneous
Answer» E. posterior femoral cutaneous

Discussion

241.	Regarding the autonomic nervous system, visceral pain is not referred to L3-5 and S1 because:
A.	there are no visceral afferents related to these lumbar splanchnic nerves
B.	there are no white rami communicans to these spinal nerves
C.	there are no sympathetic ganglia associated with theses spinal segments
D.	there is no sympathetic efferent supply to these spinal nerves
E.	there are no grey rami communicans associated with the autonomic ganglia of L3-S1 spinal nerves
Answer» C. there are no sympathetic ganglia associated with theses spinal segments

Discussion

242.	Regarding the femoral vein
A.	It receives the great saphenous vein on its anterolateral surface
B.	It drains into the internal iliac vein
C.	It lies lateral to the femoral artery within the femoral sheath
D.	It has no valves
E.	It enters the inferior part of the femoral triangle posterior to the femoral artery
Answer» F.

Discussion

243.	Holding a heavy hammer in your hand involves:
A.	only the long flexors of the fingers
B.	flexion of wrist to strengthen grip
C.	immobilisation of the shoulder joint to strengthen grip
D.	only the long flexors of fingers and opposition of the thumb
E.	requires synergic contraction of wrist extensors
Answer» F.

Discussion

244.	The blood supply to the breast involves all but one of the following:
A.	lateral thoracic artery
B.	long thoracic artery
C.	internal thoracic artery
D.	posterior intercostal artery
E.	thoracoacromial artery
Answer» C. internal thoracic artery

Discussion

245.	The medial compartment of the thigh:
A.	contains obturator internus
B.	contains the adductor canal
C.	contains the femoral triangle
D.	is limited superiorly by the obturator membrane
E.	is supplied mainly by the obturator artery
Answer» E. is supplied mainly by the obturator artery

Discussion

246.	The flexor compartment of the thigh contains which of the following muscles?
A.	gluteus maximus
B.	adductor magnus
C.	garacilis
D.	semimembranosus
E.	rectus femoris
Answer» E. rectus femoris

Discussion

247.	The medial compartment of the thigh contains all of the following except
A.	The obturator nerve
B.	Obturator artery
C.	Gracilis muscle
D.	Obturator internus
E.	Obturator externus
Answer» E. Obturator externus

Discussion

248.	Regarding autonomic nervous system, visceral pain is not referred to L3-S1 because:
A.	there are no visceral afferents related to these lumbar splanchnic nerves
B.	there are no white rami communications to these spinal nerves
C.	there are no sympathetic ganglia associated with these spinal segments
D.	there is no sympathetic efferent supply to these spinal nerves
E.	there are no grey rami communicants associated with the autonomic ganglia of L3-S1 spinal nerves
Answer» C. there are no sympathetic ganglia associated with these spinal segments

Discussion

249.	Branches of the axillary artery DO NOT include:
A.	superior thoracic
B.	subscapular
C.	medial thoracic
D.	thoracoacromial
E.	posterior circumflex humeral
Answer» D. thoracoacromial

Discussion

250.	Which is true of the superior mesenteric artery and its branches?
A.	Right colic artery is the main supply of the caecum
B.	Superior mesenteric artery runs anterior to the 1st part of the duodenum
C.	Right colic artery passes behind the right ureter
D.	Superior mesenteric arises from aorta at level of L2
E.	Main trunk of the superior mesenteric artery ends at the level of Meckel s diverticulum
Answer» F.

Discussion

Explore topic-wise MCQs in Uncategorized topics.

The orbit contains all of the following EXCEPT:

The inferior oblique

Which muscle abducts the vocal cords?

The cricoid cartilage

Larynx

The carotid triangle contains

The carotid sheath

The radial nerve gives rise to all the following except the:

The radial nerve:

Radial nerve:

Regarding the vertebrae

When performing a lumbar puncture the spinal needle should not pass through the

All the following are contents of the posterior triangle EXCEPT:

Regarding the pericardium:

The alar ligaments connect the

All the following are boundaries of the named triangle except:

Which of the following enters into the inferior meatus of the nose?

A fracture through the roof of the maxillary sinus might result in sensory loss to the

All the following structures pass through the jugular foramen EXCEPT:

The celiac trunk

Which is true of the thoracic sympathetic trunk

Regarding the sympathetic nervous system:

Which of the following is not a direct attachment of the pectoral girdle to the trunk?

Which of the following is a branch of the mandibular nerve

Which of the following has some nerve supply from the radial nerve?

which of the following is a branch of the maxillary nerve?

Laceration of the recurrent branch of the median nerve results in paralysis of all the following muscles of the thumb EXCEPT:

Which nerve is a branch of the lateral cord of the brachial plexus?

With respect to the sensory innervation of the visceral pericardium, which of the following nerves predominantly provides sensory fibres?

The vagus nerve:

Fourth lumbar nerve root supplies:

Which is true of the vagus nerves?

The medial cutaneous nerve of the arm:

Regarding lymph nodes, the lateral side of the arm and forearm is drained initially to the:

The segmental supply to the posterior cutaneous nerve of the thigh is:

The lateral aspect of the thigh has a cutaneous nerve supply derived from:

The posterior cutaneous nerve of the thigh:

The sole of the foot has a cutaneous nerve supply derived from:

The intermediate cutaneous nerve of the thigh:

The cutaneous nerve supplying the medial aspect of the calf is:

Regarding the autonomic nervous system, visceral pain is not referred to L3-5 and S1 because:

Regarding the femoral vein

Holding a heavy hammer in your hand involves:

The blood supply to the breast involves all but one of the following:

The medial compartment of the thigh:

The flexor compartment of the thigh contains which of the following muscles?

The medial compartment of the thigh contains all of the following except

Regarding autonomic nervous system, visceral pain is not referred to L3-S1 because:

Branches of the axillary artery DO NOT include:

Which is true of the superior mesenteric artery and its branches?