The Equine Pelvis. Flashcards
1
Q
What is pelvimetry?
A
The different measurements within the pelvis.
2
Q
What is the transverse diameter of the pelvis?
A
The widest point between the 2 acetabula.
3
Q
What is the conjugate diameter of the pelvis?
A
The vertical line that runs from the pecten to the promontory of the sacrum.
4
Q
What is the vertical diameter of the pelvis?
A
The line that runs from the pecten of the pubis to the ventral surface of the sacrum or CD-1.
5
Q
The vertical diameter of the pelvis is usually at what angle to the pelvic floor?
A
Perpendicular.
6
Q
What shape is the entrance to the equine pelvis?
A
It is round and quite large.
7
Q
How does the amount of soft tissue in the lateral walls of pelvis of the horse compare to that in the dog and cat?
A
There is a lot more soft tissue found in the lateral walls of the pelvis of the horse.
8
Q
What name is given to the soft tissue in the lateral walls of the pelvis?
A
The sacrotuberous ligament.
9
Q
How large is the pelvic cavity in the horse?
A
It is fairly roomy.
10
Q
How does the angle of the floor of the equine pelvis compare to that of the cow?
A
The floor of the equine pelvis is much flatter and this makes giving birth much easier.
11
Q
How does the shape of the pelvic entrance differ between the mare and the stallion?
A
In the mare it is wide and round.
In the stallion it is triangular.
12
Q
Is the sacrotuberous ligament well developed in the horse?
A
Yes.
13
Q
What shape is the horizontal axis of the equine pelvis?
A
It is fairly straight and there are no curvatures.
14
Q
Where is the scrotum of the stallion located relative to the pelvis?
A
They are ventral to the cranial end of the pelvis.
15
Q
What shape is the scrotum of the stallion?
A
It is globular with no distinct neck.
16
Q
Where is the scrotum of the stallion located?
A
In between the thighs.
17
Q
Can the scrotum of the stallion be seen from a caudal view?
A
No.
18
Q
Is the scrotum of the stallion covered in any hair?
A
No.
It has a shiny/oily appearance.
19
Q
What divides the scrotum of the stallion into 2 halves?
A
The median scrotal raphe.
20
Q
What artery supplies the scrotum of the stallion?
A
The external pudendal artery.
21
Q
What are the 3 tissue layers that make up the scrotum of the stallion?
A
The skin.
The tunica dartos.
A number of fascial sheaths.
22
Q
What is the tunica dartos that makes up the scrotum of the stallion?
A
A layer of fibroelastic tissue and smooth muscle that lies just below the skin.
23
Q
Is the tunica dartos easy to separate from the skin?
A
No.
24
Q
What is the function of the scrotal ligament?
A
It attaches the tunica dartos to the spermatic sac (vaginal tunic).
25
What are the 2 fascial sheaths of the scrotum of the stallion?
The external spermatic fascia.
The cremasteric fascia and the cremaster muscle.
The internal spermatic fascia.
26
What is formed by the tunica dartos in the midline of the scrotum?
The scrotal septum.
27
What is the external spermatic fascia of the scrotum?
It is part of the fascial sheath and it attaches to the tunica dartos.
28
What muscle does the external spermatic fascia of the scrotum arise from?
The external abdominal oblique muscle.
29
The cremasteric fascia and cremaster muscle arise form what muscle?
The internal abdominal oblique muscle.
30
What muscle does the internal spermatic fascia of the scrotum arise from?
The transversus abdominis muscle.
31
What part of the scrotum is the internal spermatic fascia attached to?
The vaginal tunic.
32
What layers of the scrotum are dissected when performing close castration?
Close castration involves cutting through the external spermatic fascia and no further.
33
What layers of the scrotum are dissected when performing close castration?
All 3 layers are cut so that we can enter the cavity of the vaginal tunic.
34
What does close castration involve?
Separating the skin and external spermatic fascia from the cremasteric fascia.
35
The cavity of the vaginal tunic is continuous with what other body cavity?
The peritoneal cavity.
36
What nerves supply the scrotum of the stallion?
Spinal nerves L2 and L3 and there is also some supply from the preputial and scrotal branch of the pudendal nerve.
37
Where are the scrotal (superficial inguinal?) lymph nodes found in the stallion?
Around the spermatic cord.
38
What shape are the testes in the stallion?
The are round or flattened mediolaterally.
39
The long axis of the testes of the stallion is orientated in what direction?
Horizontally.
40
Where is the spermatic cord located relative to the long axis of the testes of the stallion?
It is located perpendicularly to the long axis of the testes.
41
Is the mediastinum testis visible in the horse?
Not really.
42
The epididymus of the stallion is located on what aspect of the testes?
On the dorsal aspect of the testes.
43
Does the head of the epididymus of the stallion project beyond the testes?
The head of the epididymus projects slightly beyond the cranial pole of the testes.
44
Does the tail of the epididymus of the stallion project beyond the testes?
The tail of the epididymus projects slightly beyond the caudal pole of the testes.
45
Is the ligament of the tail of the epididymus well formed in the stallion?
Yes.
46
What is the function of the ligament of the tail of the epididymus?
It attaches the tail of the epididymus to the vaginal tunic.
47
What is the function of the proper of the epididymus?
It attaches the tail of the epididymus to the caudal pole of the testes.
48
Where does the deferent duct of the epididymus leave the epididymus?
At the tail and it ascends cranially as part of the spermatic cord.
49
What is the major artery that supplies the testes of the stallion?
The testicular artery.
50
What about the blood supply to the testes of the stallion is unique to the horse?
The tortuous branches that are formed on the testes by the blood vessels.
51
Where is the testicular artery found relative to the spermatic cord?
It is found on the caudal border of the spermatic cord.
52
What shape is the testicular artery as it approaches the testes?
It is tortuous.
53
What organs are supplied by the testicular artery?
The testes.
The epididymus.
54
What is the pampiniform plexus?
a network of veins that surround the testicular artery as it enters the testes.
55
Does the paminiform plexus surround the testicular vein?
No.
56
In the stallion, which blood vessels run along with the ductus deferens?
The cremasteric/deferent artery and vein
57
What lymph node is found near the testes?
The medial iliac lymph node.
58
What colour is the parenchyma of the testes in the stallion?
Yellow.
59
How do the lymphatic vessels travel to the medial iliac lymph node of the testes?
They follow the same course as the testicular veins.
60
How does open castration occur?
We cut through the skin to the vaginal process.
61
How does closed castration occur?
The skin, the tunica dartos and the external spermatic fascia are cut.
Then the testes are removed.
62
What procedure allows the horse to retain its testes and libido, but not produce any sperm?
Sterilisation.
63
How does the process of sterilisation occur?
Open the vaginal process.
Cut between the tail of the epididymus, the body of the epididymus and the ductus deferens.
Remove the cut tail tissue.
64
Does the stallion lack any accessory sex glands?
No, it has all of the accessory sex glands.
65
Is the ampulla of the ductus deferens well developed in the horse?
Yes, it is very well developed.
66
The ampulla shares a common duct with which other sex gland?
The vesicular gland.
67
Where does the ejaculatory duct of the stallion open?
To the side of the seminal colliculus.
68
What is the seminal colliculus?
A mound that is part of the proximal part of the urethra.
69
What shape is the vesicular gland in the stallion?
It is a pear shaped sack.
70
Where is the vesicular gland found in the stallion?
It is found within the genital fold, on the dorsal side of the urinary bladder.
71
What are the 2 layers of the walls of the vesicular gland in the stallion?
Serous and muscular layers.
A mucosa containing tubular glands.
72
Where is the neck of the vesicular gland located?
Underneath the prostate gland.
73
The vesicular gland shares a common duct with what other sex organ?
The ductus deferens.
74
What parts of the prostate are found in the horse?
Only the body.
There is no disseminate part.
75
Where is the prostate found in the stallion?
It lies across the neck of the urinary bladder and it is at the origin of the urethra.
76
What connects the left and right lobes of the prostate in the stallion?
An isthmus.
77
Is the prostate located near the vesicular gland and the ductus deferens?
Yes.
It is located at the distal ends of these organs.
78
Is the prostate of the stallion lobated?
Yes.
79
What is the size of the quine prostate gland?
Around the same size as that of carnivores.
80
Where do the ducts of the prostate open into?
The 20 ducts open on either side of the seminal colliculua.
81
What are the 2 parts of the urethra in the stallion?
The pelvic part.
The non pelvic part.
82
What is the origin of the pelvic urethra covered by on its dorsal surface?
The urethralis muscle.
83
What is most of the pelvic urethra covered by on its dorsal surface?
The accessory sex glands.
84
Where do the sex glands open into the urethra?
At the colliculus seminalis which is a small hillock.
85
What can be seen through the colliculus seminalis of the urethra?
The uterus masculinus.
86
What is surrounded by the corpus spongiosum penis?
The urethra.
87
What is surrounded by the corpus cavernosum penis?
The whole penis.
88
Does the corpus cavernosum fuse to the corpus spongiosum in the stallion?
Yes, they fuse to form a single corpus at the dorsal part of the penis.
89
Where do the roots of the penis originate from?
The tuber ischiadicum and they fuse to form the body of the penis.
90
What is found at the ventral aspect of the corpus cavernosum penis?
A small groove which is where the corpus spongiosum penis is found.
91
Are the blood spaces in the the corpus cavernosum and the corpus spongiosum of the stallion?
Yes.
92
What kind of penis is the stallion said to have?
A muscular cavernous penis.
93
What kind of muscle is found in the penis of the stallion?
Smooth muscle which is longitudinally orientated in the trabeculae.
94
What part of the equine penis is surrounded by tunica albginea?
The corpus cavernosum.
95
What part of the penis is formed by corpus cavernosum?
The glans penis.
96
How is the penis held within the body when the horse is in a sympathetic state?
The muscles are contracted and the penis remains within the prepuce.
97
Where are the urethra and corpus spongiosum located within the penis?
They are ventral to the corpus cavernosum are are both outside the tunica albuginea.
98
What muscle encloses the entire corpus spongiosum?
The bulbospongiosus muscle.
99
Are the retractor penis muscles paired?
Yes.
100
Where are the retractor penis muscles found in the horse?
They run along the entire ventral part of the body of the penis.
101
The bulbospongiosus muscle is a continuation of what muscle?
The urethralis muscle.
102
Why is the bulbospongiosus muscle unusual in the horse?
As it extends beyond the glans penis.
103
How will damage to the retractor penis muscle affect the horse?
The horse will be able to pull the penis into the prepuce.
104
What are the 3 muscles associated with the penis of the stallion?
The 2 retractor penis muscles.
The bulbospongiosus muscle.
105
What are the 3 main parts of the glans penis of the stallion?
The corona glandis.
The dorsal process of the glans penis.
The collum glandis (neck).
106
Where on the penis is the corona glandis found?
At the terminal end of the penis.
107
What is the corona glandis of the penis?
A raised margin at the terminal end of the penis.
It looks like a crown at the end of the penis.
108
Is the free end of the equine penis blunt or pointy?
It is blunt.
109
What structure is formed at the end of the urethra?
The urethral process.
110
What is the urethral process surrounded by?
The fossa glandis.
111
Does the urethral process project beyond the glans penis?
Yes.
112
What is found within the fossa glandis?
A dorsal diverticulum called the urethral sinus.
113
What can build up inside the urethral sinus of the penis of the stallion?
Smegma.
This can be very painful as there are many nerve endings in the penis.
114
What surrounds the urethral process of the stallion?
A shallow groove called the fossa glandis.
115
What is the fossa glandis responsible for?
For separating the urethral process from the glans penis.
116
What is found at the dorsal aspect of the fossa glandis?
The urethral sinus.
117
What behaviour will the stallion perform if its penis is painful?
It will try to kick its penis and this can often be mistaken for signs of colic.
118
What name is often given to the smegma that builds in the urethral sinus?
The bean.
119
How is the prepuce of the stallion shaped?
It is formed from 2 folds.
120
What are the 2 folds that form the prepuce of the penis?
The inner fold.
The outer fold.
121
What is the shape of the external lamina of the prepuce of the penis in the horse?
The external lamina folds back on itself at the outer preputial fornix to form an extra lamina.
This lamina runs cranially to form the extra fold of the internal lamina.
122
Where is the main opening of the external lamina of the prepuce of the penis?
At the preputial orifice.
123
Where does the extra fold of the prepuce of the penis attach to?
The inner preputial fornix.
124
What name is given to the inner fold of the prepuce?
The preputial fold.
125
What happens to both folds of the prepuce at erection?
Both folds are pulled over the elongated shaft of the penis.
126
What is the function of the cranial and caudal preputial muscles?
The protract and retract the prepuce.
127
Are the cranial and caudal preputial muscle found in the stallion?
No,
128
What keeps the penis within the penis within the prepuce in the stallion?
The muscle tone of the muscles of the trabeculae of the corpus cavernosum penis keeps the penis within the prepuce.
129
The artery of the penis is the terminal part of what artery?
The internal pudendal artery.
130
What artery supplies the penis in most species?
The internal pudendal artery/the artery of the penis.
131
What 3 arteries that supply the penis are branches of the internal pudendal artery?
Artery of the penis.
132
What 3 arteries supply the artery of the penis in the horse?
The artery of the penis.
The obturator artery.
The external pudendal artery.
133
How does the obturator artery arrive at the penis?
It passes through the obturator foramen and travels to the dorsal part of the penis.
It then forms 2 branches which merge with the artery of the penis.
134
How does the external pudendal artery arrive at the penis?
It passes through the superficial inguinal ring and anastamoses with the obturator artery.
135
What name is sometimes given to the blood vessel that is formed after the external pudendal artery has anastamosed with the obturator artery?
The cranial artery of the penis.
136
What are the 3 major branches of the artery of the penis?
The deep artery of the penis.
The dorsal artery of the penis.
The artery of the bulb.
137
What part of the penis is supplied by the deep artery of the penis?
The erectile tissue at the root of the penis.
138
What is supplied by the dorsal artery of the penis?
The dorsal surface of the penis.
139
What is supplied by the artery of the bulb?
The bulb of the penis.
140
Is the penis supplied by the external pudendal artery in many animals?
No, only in the horse.
141
What artery of the penis is derived from the external pudendal artery?
The cranial artery of the penis.
142
What is the main vein that drains the penis?
The internal pudendal vein.
143
The internal pudendal vein flows into what vein?
The internal iliac vein.
144
The dorsal vein of the penis flows into what vein?
The internal pudendal vein.
145
What vein accompanies the obturator artery and what part of the penis does it drain?
The internal pudendal vein and it drains the area supplied by the obturator artery.
146
How does the external pudendal artery enter the penis?
It passes through the inguinal ring.
147
Does the external pudendal vein pass through the inguinal ring to get to the penis?
No, it passes through the tendon of origin for the gracillus and pectineus muscles.
148
How does the penis of the stallion become erect?
When a stallion mates he abducts his legs and this puts pressure on the adductor muscles and the external pudendal vein.
This makes it difficult for blood to leave the penis and this allows the stallion to achieve an erection.
149
What kind of muscles are the gracillus and pectineus muscles?
Adductor muscles.
150
What are the main 3 veins that drain the penis?
The internal pudendal vein.
The external pudendal vein.
The obturator vein.
151
The obturator vein of the penis flows into what vein?
The internal iliac vein.
152
What blood vessels supply the prepuce in the stallion?
The dorsal artery and vein of the penis.
By branches of the superficial epigastric arteries on each side.
153
The deep inguinal lymph nodes send afferents to what other lymph nodes?
To the medial iliac lymph nodes.
