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In some animals, the male penis possesses a muscle enabling retraction into the prepuce.
| You can help expand this article with text translated from the corresponding article in German. (March 2013)Click [show] for important translation instructions.
|
In some animals, the male penis possesses a muscle enabling retraction into the prepuce.
The retractor penis muscle occurs in marsupials and carnivorans, but it is absent in humans. [1] A stag's penis forms an S-shaped curve when it is not erect, and is retracted into its preputial sheath by the retractor penis muscle. [2]
In Tandonia, the retractor penis inserts at the boundary between the penis and epiphallus. [3]
In stallions, the retractor penis muscle is relatively underdeveloped. [4] The retractor muscle contracts to retract the penis into the sheath and relaxes to allow the penis to extend from the sheath. [5]
In bulls, protrusion is not affected much by erection, but more by relaxation of the retractor penis muscle and straightening of the sigmoid flexure. [4]
Sheath, pronounced, may refer to:
The pudendal nerve is the main nerve of the perineum. It is a mixed nerve and also conveys sympathetic autonomic fibers. It carries sensation from the external genitalia of both sexes and the skin around the anus and perineum, as well as the motor supply to various pelvic muscles, including the male or female external urethral sphincter and the external anal sphincter.
In female humans and other mammals, the clitoral hood is a fold of skin that surrounds and protects the glans of the clitoris; it also covers the external clitoral shaft, develops as part of the labia minora and is homologous with the foreskin in the male reproductive system. The clitoral hood is composed of mucocutaneous tissues; these tissues are between the mucous membrane and the skin, and they may have immunological importance because they may be a point of entry of mucosal vaccines.
A gelding is a castrated male horse or other equine, such as a pony, donkey or a mule. The term is also used with certain other animals and livestock, such as domesticated camels. By comparison, the equivalent term for a castrated male bull would be ox, or a wether for rams and billy goats.
The femoral triangle is an anatomical region of the upper third of the thigh. It is a subfascial space which appears as a triangular depression below the inguinal ligament when the thigh is flexed, abducted and laterally rotated.
The rectus abdominis muscle, also known as the "abdominal muscle" or simply the "abs", is a pair of segmented skeletal muscle on the ventral aspect of a person's abdomen. The paired muscle is separated at the midline by a band of dense connective tissue called the linea alba, and the connective tissue defining each lateral margin of the rectus abdominus is the linea semilunaris. The muscle extends from the pubic symphysis, pubic crest and pubic tubercle inferiorly, to the xiphoid process and costal cartilages of the 5th–7th ribs superiorly.
Semen collection refers to the process of obtaining semen from human males or other animals with the use of various methods, for the purposes of artificial insemination, or medical study. Semen can be collected via masturbation, prostate massage, artificial vagina, penile vibratory stimulation (vibroejaculation) and electroejaculation. Semen can be collected from endangered species for cryopreservation of genetic resources.
The bulbus glandis is an erectile tissue structure on the penis of canid mammals. During mating, immediately before ejaculation the tissues swell up to lock (tie) the male's penis inside the female. The locking is completed by circular muscles just inside the female's vagina; this is called "the knot" tightening thus preventing the male from withdrawing. The circular muscles also contract intermittently, which has the effect of stimulating ejaculation of sperm, followed by prostatic fluid, as well as maintaining the swelling of the penis and therefore the tie, for some time. For domestic dogs the tie may last up to half an hour or more, though usually less. When male canines are sexually excited, the bulbus glandis may swell up inside the penile sheath, even if the dog has been neutered.
A stallion is a male horse that has not been gelded (castrated). Stallions follow the conformation and phenotype of their breed, but within that standard, the presence of hormones such as testosterone may give stallions a thicker, "cresty" neck, as well as a somewhat more muscular physique as compared to female horses, known as mares, and castrated males, called geldings.
The dorsal artery of the penis is an artery on the top surface of the penis. It is a branch of the internal pudendal artery. It runs forward on the dorsum of the penis to the glans, where it divides into two branches to the glans penis and the foreskin (prepuce).
Tandonia is a genus of air-breathing, keeled, land slugs. These are shell-less terrestrial gastropod mollusks in the family Milacidae.
In human male anatomy, the radix or root of the penis is the internal and most proximal portion of the human penis that lies in the perineum. Unlike the pendulous body of the penis, which is suspended from the pubic symphysis, the root is attached to the pubic arch of the pelvis and is not visible externally. It is triradiate in form, consisting of three masses of erectile tissue; the two diverging crura, one on either side, and the median bulb of the penis or urethral bulb. Approximately one third to one half of the penis is embedded in the pelvis and can be felt through the scrotum and in the perineum.
In many animals, a penis is the main male sexual organ used to inseminate females during copulation. Such organs occur in both vertebrates and invertebrates, but males do not bear a penis in every animal species.
An erection is a physiological phenomenon in which the penis becomes firm, engorged, and enlarged. Penile erection is the result of a complex interaction of psychological, neural, vascular, and endocrine factors, and is often associated with sexual arousal, sexual attraction or libido, although erections can also be spontaneous. The shape, angle, and direction of an erection vary considerably between humans.
In most terrestrial mammals, the scrotum or scrotal sac is a part of the external male genitalia located at the base of the penis. It consists of a sac of skin containing the external spermatic fascia, testicles, epididymides, and vasa deferentia. The scrotum will usually tighten during penile erection and when exposed to cold temperatures.
Anostoma depressum is a species of air-breathing land snail, a terrestrial pulmonate gastropod mollusc in the family Odontostomidae.
The reproductive system of gastropods varies greatly from one group to another within this very large and diverse taxonomic class of animals. Their reproductive strategies also vary greatly.
An intromittent organ is any external organ of a male organism that is specialized to deliver sperm during copulation. Intromittent organs are found most often in terrestrial species, as most non-mammalian aquatic species fertilize their eggs externally, although there are exceptions. For many species in the animal kingdom, the male intromittent organ is a hallmark characteristic of internal fertilization.
In male human anatomy, the foreskin, also known as the prepuce, is the double-layered fold of skin, mucosal and muscular tissue at the distal end of the human penis that covers the glans and the urinary meatus. The foreskin is attached to the glans by an elastic band of tissue, known as the frenulum. The outer skin of the foreskin meets with the inner preputial mucosa at the area of the mucocutaneous junction. The foreskin is mobile, fairly stretchable and sustains the glans in a moist environment. Except for humans, a similar structure known as a penile sheath appears in the male sexual organs of all primates and the vast majority of mammals.
Almost all mammal penises have foreskins or prepuces, although in non-human cases, the foreskin is usually a sheath into which the whole penis is retracted. In koalas, the foreskin contains naturally occurring bacteria that play an important role in fertilization. In some bat species, the prepuce contains an erectile tissue structure called the accessory corpus cavernosus.
"Genus summary for Tandonia". AnimalBase, last modified 23 May 2010, accessed 26 August 2010.