SPOT/OSPE Revision Flashcards
The left and right recurrent laryngeal nerves loop under what when running up towards the neck?
Left=aorta
Right=right subclavian artery
Describe the path of the vagus nerve
Cranial nerve 10. Arises from brain, then goes to nodose ganglion. Joins with sympathetic trunk (but nothing to do with it) at the cranial cervical ganglion. These split at the middle cervical ganglion. Vagus supplies branches to the heart and lungs before dividing into a dorsal and ventral branch. At around the level of the diaphragm, the left and right dorsal and ventral branches join to give a single dorsal branch (supplies visceral surface of stomach/pylorus) and a single ventral vagal trunk (supplies parietal surface of pylorus and liver) within the abdomen
The recurrent laryngeal nerve is a branch of which nerve?
Vagus
Where does the thoracic duct lie?
What does it do?
Drains lymph from the gut into the cranial vena cava
Is unpaired
Lies on the left in the thorax
Is found on the oesophagus cranial to the aorta
What passes through the foramen magnum in the skull?
Spinal cord
In the cow, the horns are continuous with which sinus?
Frontal
Where are the trephine points in a horse?
2 over the frontal sinus
1 over the rostral maxillary sinus
1 at the junction between the rostral and caudal maxillary sinus
Which muscles form the pelvic diaphragm?
Levator ani Coccygeus Rectococcygeus Internal and external anal sphincters Internal obturator
How are muscles moved around/sutured during a herniorrhaphy?
The coccygeus is sutured to the external anal sphincter. Next the internal obturator muscle is elevated off the floor of the pelvis, its tendon is incised, and it is reflected dorsomedially and sutured to the external anal sphincter
Which species posses a tracheal bronchus? Which lung lobe does it supply?
Pigs and ruminants
Supplies right cranial lobe
Branches off trachea, cranial to the tracheal bifurcation
Tertiary bronchi supply what?
Lobules
Which lung lobe is missing in horses?
Right middle
What is the epiploic foramen bordered by?
Hepatic portal vein, liver and caudal vena cava
What is the function of the platysma?
Which nerve supplies it?
Draws the commissure of the lips caudally
Cervical branch of facial nerve
What lies either side of the facial vein?
Mandibular lymph nodes (can be easily palpated)
Where do all the structures of the head drain through?
Retropharyngeal lymph nodes (just below wing of atlas)
Where does the parotid salivary gland open into?
What is it innervated by?
What type of saliva does it produce?
Where is its duct located?
Opens into the mouth on the buccal mucosa, at the level of the 4th upper premolar
Parasympathetic innervation is by glossopharyngeal, but the fibres reach the gland in a branch of the trigeminal
Serous saliva
Runs across the masseter muscle
The mandibular salivary gland lies where?
What sort of saliva does it secret?
Where does its duct run?
What is it innervated by?
In the v formed by the linguofacial and maxillary veins
Mixed (serous and mucous)
Its duct passes medioventrally and runs with the sublingual duct
Parasympathetic innervation is by facial nerve fibres passing in the chorda tympani to a branch of trigeminal, then on to the gland
What is the masseter innervated by?
Mandibular branch of trigeminal
What are the 2 bellies of digastricus innervated by?
Rostral belly: trigeminal
Caudal belly: facial
What is the mylohyoid innervated by?
Mylohyoid nerve from mandibular branch of trigeminal
What attaches the tongue to the floor of the mouth?
What are the pair of swellings at the rostral edge of this?
Frenulum
Sublingual caruncles-site of orifices of the sublingual and mandibular ducts
What does the great auricular nerve of C2 supply?
Caudal ear muscles
The auriculopalpebral nerve is a branch of which nerve?
What does it further divide into?
Facial
Rostral auricular nerve (innervates rostral ear muscles) and palpebral nerve (innervates eyelid muscles)
What would be the effect of cutting the palpebral branch of the auriculopalpebral nerve?
Would be some drooping of eyelid, but an inability to fully close the eye, as palpebral branch supplies some muscles of upper eyelid: Orbicularis occuli, retractor anguli occuli, superciliaris.
However, the main retractor of the upper eyelid is the Levator Palpebrae Superioris, and as this is innervated by the occulomotor nerve, only a partial closure of the eye is observed
What does the facial nerve innervate?
Motor innervation to all superficial head and ear muscles, caudal belly of digastricus, platysma, stylohyoideus
Special visceral afferents (taste) to rostral 2/3 of tongue
General visceral efferents to lacrimal gland, mandibular and sublingual glands, and the nasal, buccal and lingual mucosa glands
What are the 3 main branches of the common carotid artery in the neck?
(Caudally to cranially)
Internal carotid artery
Pharyngeal artery
Occipital artery
What are the main branches of the mandibular trigeminal nerve?
Auriculotemporal nerve (sensory to skin of ear and temple) Mylohyoid nerve (motor to digastricus and mylohyoid muscles, sensory to skin) Mandibular alveolar nerve (sensory to teeth and lips) Lingual nerve (sensory to tongue) Buccal nerve (sensory to cheek mucosa)
Which muscle runs inside the frenulum?
Genioglossus
Which muscle depresses the ear?
What is it innervated by?
Parotidoauricularis
Facial nerve
What muscles is the femoral triangle made up of?
Cranially: sartosius
Caudally: pectineus and adductor
Deeply: iliopsoas
What are the functions of biceps femoris?
Hip extensor
Stifle flexor
Hock extensor
The sacrotuberous ligament is in close proximity to which nerve?
Ischiatic nerve
What is the function of the tenuissimus?
Stifle flexor
Where does the ischiatic nerve run?
Between the greater trochanter of the femur and the ischiatic tuberosity of the pelvis
Where does the vastus lateralis head of the quadriceps originate and insert?
What is its action?
What innervates it?
O=greater trochanter of femur
I=tibial tuberosity by way of the patellar ligament
A=extends stifle
In=Femoral nerve
Which vessels are within the femoral triangle?
Femoral artery
Femoral vein
Femoral nerve
The ischiatic nerve splits into what?
Tibial nerve and peroneal (fibular) nerve
The saphenous nerve is a branch of which nerve?
Femoral
What does the femoral artery split into at the medial stifle?
Popliteal artery and distal caudal femoral artery
Unlike the forelimb, the hindlimb has 2 sets of digital extensor muscles. What are they are where do they originate?
Long digital extensors: femur
Short digital extensors: metatarsals
In the hindlimb, where does the superficial digital flexor originate and insert?
What are its actions?
What is it innervated by?
O=lateral supracondylar tuberosity of femur
I=bases of middle phalanges of digits 2-5
A=flex the stifle, flex digits 2-5, extend tarsus
In=tibial nerve
The deep digital flexor has how many heads in the hindlimb?
What are they innervated by?
2: lateral digital flexor and medial digital flexor
Tibial nerve
In the horse hindlimb, the plantar nerves arise from which nerve?
Tibial
What are the palmar/plantar annular ligaments in the horse?
Fibrous band that wraps around the flexor tendons as they pass over the fetlock sesamoid bones on the palmar/plantar surface of the limb
Where should you inject when performing a palmar digital nerve block?
How much of the foot does it block?
Which nerves does it affect?
1cm above coronary band, 2/3 of the way to palmar aspect (both medial and lateral)
Blocks caudal 1/2 of foot (including navicular bone, distal sesamoid)
Palmar digital nerves
Where should you inject when performing an abaxial sesamoid nerve block?
How much of the foot does it block?
Which nerves does it affect?
At the abaxial aspect of the sesamoids (medial and lateral)
Blocks entire foot
Affects palmar digital nerves and dorsal branches
Where should you inject when performing a palmar metacarpal nerve block?
How much of the foot does it block?
Which nerves does it affect?
Inject 2cm proximal to sesamoids, at the distal end of the splint bones
Blocks entire digit (fetlock joint and all structures below)
Affects palmar nerves and palmar metacarpal nerves
4-point block (FL), 6-point block (HL)
What does the suspensory ligament join with on the cranial aspect of the hoof?
What is its function?
Common digital extensor tendon
Prevents collapse of the metacarpophalangeal joint during weight-bearing
Explain the patellar-locking mechanism in the horse
When the stifle is extended, the patella is proximal. To lock it in place, the patella is rotated medially and engages with the horizontal/resting surface of the trochlea of the femur. The tubercle of the medial trochlear ridge is now between the middle and medial patellar ligaments. This locks the joint in extension. No muscle activity is needed to maintain this position. To unlock, the horse shifts its weight to the other limb, and the quadriceps contract, drawing the patella proximally then laterally, back to mid-line.
How would you distinguish between a boar and a stallion’s penis?
No sigmoid flexure in stallion
Which blood vessels supply the penis?
What is this a branch of?
What does they continue as?
Internal pudendal artery/vein
Branch of the internal iliac
Continues as the dorsal artery of the penis
Which blood vessels supply the skin of the penis (prepuce)?
What also contributes in the horse?
Caudal superficial epigastric artery/vein
External pudendal artery/vein
What are the pros and cons of closed castrations?
Pros:
Don’t enter peritoneal cavity so less chance of infection
Rapid, easy technique
As the vaginal tunic is not entered, less chance of bleeding from incising it
Tunics and testicles remain intact, so less possibility of seeding local wound with tumour cells
Decreased chance of seromas forming at the incision site (pockets of fluid from blood plasma seeping out from ruptured blood vessels)
Less scrotal swelling
Cons:
If ligaments are not secure, risk of bleeding
No tension must be placed on spermatic cord during clamping and ligation and extra care is required to place secure ligatures since vessels are only indirectly ligated (placed around tunic, not directly on vessels)-chance of ligatures slipping or loosening
What are the pros and cons of open castrations?
Pros:
Ligatures can be placed directly onto testicular vessels and ductus deferens, thereby minimising the chance of them slipping or loosening
Cons:
Operating time slightly longer
Indirect opening into peritoneal cavity is created-chance of infection
What is the glans penis made up of?
Bulbus glandis covers proximal half of os penis
Pars longa glandis covers distal half of os penis
The crura of the penis are derived from what?
What do they become?
Ischium of pelvis
Corpus cavernosum
Where is sperm produced?
Seminiferous tubules
What stimulates sperm maturation?
Production and release of FSH and testosterone
Where does sperm mature and be stored?
Epididymis
Concentrates in the tail
Maturation takes 8-15 days
Explain emission and ejaculation
Emission=movement of seminal fluids from accessory sex glands (prostate in dog, also ampulla in other species except pig, vesicular glands except cat/dog, bulbourethral gland except dog) into pelvic urethra, which then mix with spermatozoa
Ejaculation=expulsion of spermatozoa and seminal plasma. Under sympathetic control
How is erection achieved and maintained?
Erotogenic stimuli cause sensory nerves to fire and activate ‘reproductive behaviour centre’ in hypothalamus. Stimulation of parasympathetic nerves release NO, this causes vasodilation and hence an erection. Dilation of corporal sinusoids, relaxation of retractor penis muscle, restriction of venous outflow, elevated arterial blood flow (internal pudendal artery), elevated intrapenile pressure.
Erection is maintained by contraction of ischiocavernosus and bulbospongiosus muscles-prevent venous outflow, rhythmic contractions increase pressure in corpus cavernosum during erection.
What are the 3 muscles of the penis?
Retractor penis muscle=retracts penis back into sheath
Ischiocavernosus and bulbospongiosus muscles=prevent venous drainage of blood during erection, rhythmic contractions increase pressure in corpus cavernosum during erection
Which blood vessels supply the scrotum?
External pudendal artery and vein
What are the 2 types of corpus cavernosum?
Musculocavernous: smooth muscle with large cavernous spaces (horse and dog)
Fibro-elastic: fibrous and elastic tissue arranged in a sigmoid flexure with small cavernous spaces (bull, ram, boar)
How does the blood supply to the testes ensure that blood reaching them is cooler than core body temperature?
The testicular vein is arranged in a mesh encasing the testicular artery, allowing cooling of arterial blood via heat exchange with venous blood from the testes
What do sertoli cells produce?
Inhibin-converts testosterone to oestrogen
Which cells produce testosterone?
Leydig cells
Why may an animal still show sexual interest/be fertile for a time after being castrated?
May be some sperm ‘in storage’ in the spermatic ducts
What are the 3 major branches off the caeliac artery?
Hepatic artery
Left gastric artery
Splenic artery
Which spinal nerves make up the peripheral nervous system in the GI tract?
What do the dorsal branches supply?
What do the ventral branches supply?
T13 (number of last rib, so T18 in horse) and L1-L5
Dorsal abdominal skin
Ventral:
Medial branch: supplies transverse abdominal, internal oblique, and rectus abdominis
Lateral branch: supplies internal and external obliques
Lateral cutaneous branch: supplies lateral skin
Where do the pre-ganglionics of the major and minor splanchnic nerves synapse in the abdomen?
Caeliaco-mesenteric ganglia
Where do the pre-ganglionics of the lumbar splanchnic nerves synapse in the abdomen?
Caudal mesenteric ganglion
Where does the pelvic nerve originate?
Where does it pass through?
S1-S3
Passes through pelvic plexus then follows arteries to pelvic organs of innervation
What are the 3 major branches off the aorta and what do they innervate?
Caeliac artery: cranial abdominal organs
Cranial mesenteric: mid-abdominal organs
Caudal mesenteric: caudal abdominal organs
What are the 3 major branches off the cranial mesenteric artery?
Ileo-colic artery: splits into 5 branches Caudal pancreatico-duodenal artery (caudal right lobe of pancreas and duodenum) Jejunal arteries (jejunum)
What are the 5 branches off the ileo-colic artery?
Middle colic artery (transverse colon)
Right colic artery (right colic flexure)
Colic branch of ileo-colic (ascending colon)
Caecal branch of ileo-colic (caecum). Branches into anti-mesenteric ileal artery (ileum)
Mesenteric ileal artery (ileum)
All GI organs drain via which vein?
Hepatic portal vein
Enables liver to metabolise/detoxify
Venous return from the liver to general circulation is via which veins?
What do they drain into?
What are the 2 exceptions?
Hepatic veins draining into caudal vena cava
Except left gastric which drains into splenic not hepatic portal
Except left testicular vein which drains into left renal vein not caudal vena cava
Where do non-GI organs drain?
Directly into caudal vena cava
How many caeliac veins are there?
None
What is the periople of the hoof?
Small band of soft tissue which covers the coronary band, and widens at the heels
What do the following attach: Mesentery Omentum Fold Ligament
Mesentery-bowel to body wall
Omentum-stomach to something
Fold-bowel to bowel
Ligament-non-bowel to something
What are the 3 ligaments of the liver?
Falciform ligament: liver to ventral body wall
Coronary ligament: liver to diaphragm
Triangular ligament: (R & L) liver to diaphragm
Which muscles are attached to the pterygoid process of the skull?
What do they do?
Pterygopharyngeus- constricts and shortens the pharynx
Pterygoid- closes the jaw and allows lateral movement of the mandible with respect to the skull
Which muscle dilates the pharynx?
Stylopharyngeus
Which muscles constrict and shorten the pharynx?
Palatopharyngeus
Pterygopharyngeus
Which bones make up the hard palate?
Incisive, maxilla, palatine bones
What are the 2 large holes in the hard palate?
Palatine fissure
What pass through the palatine foramen?
Major palatine artery, vein and nerve