Flashcards in SPOT/OSPE Revision Deck (225)
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?
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?
Left gastric 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
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?
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?
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?
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-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?
Which muscles constrict and shorten the pharynx?
Which bones make up the hard palate?
Incisive, maxilla, palatine bones
What are the 2 large holes in the hard palate?