Penis Flashcards
Penis 3 parts
Root (base)
Body (shaft)
Glans (distal head)
Root of penis role
Attaches to the ischial arch Has three section 3 tapering processes which make up the root of the penis one bulb Two crura
Body of the penis parts
wo crus and on bulb
Two tissue types Corpus cavernosum (dorsal)- paired Corpus spongiosum (ventral) surrounds the urethra
Body of the penis parts
two crus and on bulb
Two tissue types Corpus cavernosum (dorsal)- paired Corpus spongiosum (ventral) surrounds the urethra
Tunica albuginea is different to the testis one
These tissues fill with blood, that is how there is an erection
Glans penis
Only corpus spongiosum and urethral opening
Glans highly sensory - ejacluation stimulation
Shape of glans + urethral opening is highly variable across species
Penile blood supply
Via the pudendal vessel ( largely the internal)
Major vessels
dorsal artery and dorsal vein
Cavernous artery runs within the corpus cavernosum
Bulbs-urethral artery
Smaller - circumflex vessels
Muscles in the penis
Two distinct group
1. Ischiocavernosus muscle- 2x one on each crus, role is to contract to maintain blood in erection
2. Bulbospongiosus muscle
2x either side of bulb, contract to help empty urethra, connect penis to ischial arch,
Explain the urethralis muscle
Contraction movement of sperm and seminal plasma into penile urethra
Retractor penis muscle
Runs from caudal vertebrae along ventral length of penis
Contraction = penis held inside body
Relation penis extended outside Body
Only presenting some species
Ligaments of the penis
Suspensory ligament - connects to pubic symphysis
Fungiform ligament- attaches to linea alba
What are two penis types
Musculo-cavernous
large volume of c. Cavernosa
Expands upon erection
Stallion, dog, tom
Fibroelastic limited c. Cavernosa Presence of sigmoid flexure Straightens upon erection Bull, ram, boar
Explain the sigmoid flexure
Only in fibroelastic
Created by retractor penis muscle
Bull penis structure
Fibroelastic penis
Curved glands
With small urethral process
Does engorge with blood slightly
Ram penis structure
Fibroelastic penis
Rounded glans, with long urethral process
Stalllion penis structure
Large musculocavernous penis
Round urethral processs surrounded by fossa glandis
Diverticulum( bean = accmulate smegma)
Boar penis
fibroelastic penis
Glans is corkscrew shaped - more apparent in erect penis
Penis structure of dog
Bulbous glandis and the pars long glandis as a bone ( the os penis aka baculum)
Penis cats
Small
Musculocavernous penis
Cone shaped glans with keratinous spines
androgen depends stimulate female during mating
Also has a small os penis
Glands has caudal orientation not ventral when flaccid
