Erectile tissue
A corpus cavernosum , corpus cavernosum , is with blood -filling and thereby fulfilling physical tasks vascular plexus . Anatomically, it is an arterial or venous vascular network. It consists of a large number of adjacent, spacious cavities lined with endothelium . With a temporary increase in blood volume, it fulfills the tasks of an erecting or sealing function.
In the narrower sense, the penis or clitoral cavernous body is meant (straightening function). The blood supply is regulated by blocking arteries and arteriovenous anastomoses. During sexual arousal , an erection occurs due to an increase in the flow of blood and a throttling of the outflow of blood in the erectile tissue and thus increased blood filling in the female and male corpora cavernosa . This is physiological, one of the conditions for the reproduction by the relish experienced sexual intercourse ( coitus ).
Erectile tissue of the penis
In the male reproductive organ of mammals , three cavernous bodies are distinguished (see also the penis of mammals ). These are:
- Penile cavernous body, corpus cavernosum penis ;
- Cavernous urethra, corpus spongiosum penis or generally corpus cavernosum urethrae ;
- Corrugated penis , corpus spongiosum glandis as a continuation of the corpus spongiosum penis .
Corpus cavernosum penis
The corpus cavernosum penis ("penis cavernous body") begins in pairs in the penis thighs ( crura penis ) and attaches to the ischium . The two corpus cavernosum limbs unite in the area of the penis body to form the now unpaired corpus cavernosum , in which in some mammals a septum still indicates the original pairing.
The erectile tissue is surrounded by a thick connective tissue capsule ( tunica albuginea ), which ensures that the penis stiffens and elongates during erection and does not inflate like a balloon. From the capsule septa go into the interior, which in some animal species (e.g. horses ) also contain smooth muscles .
The corpus cavernosum penis is an arterial cavernous body. The flaccid penis is bloodless. During an erection, so-called blocking arteries ( arteriae helicinae ) open and fill the erectile tissue with blood. At the same time the venous outflow is stopped.
In some mammals such as primates (except humans), predators , insectivores or bats , the penile cavernous body is ossified to form the penis bone ( os penis ) or converted into a cartilage tube .
Corpus spongiosum penis
The corpus spongiosum penis (also: corpus cavernosum urethrae , "urethral erectile tissue") is bulky in the area of the penis root ( bulb penis ). It lies on the underside of the penis and surrounds the urethra (urethra). It has only a weak tunica albuginea and is rich in elastic fibers that keep it plastic during an erection and prevent the urethra from compressing.
The erectile tissue of the urethra is a so-called venous erectile tissue. Blood flows through it even when it is relaxed. The erection, which is weak in contrast to the erectile tissue of the penis, is achieved by throttling the venous blood flow.
Corpus spongiosum glandis
The corpus spongiosum glandis (" glans penis ") is the swelling tissue of the glans ( glans penis ). It is the continuation of the erectile tissue of the urethra on the front end of the penis and ensures the thickening of the glans during erection.
In dogs , the erectile tissue of the penis is very well developed and only fills up after the penis is inserted during copulation. The swelling persists for up to 30 minutes after ejaculation , during which time the male dog “hangs” on the bitch. A violent separation is not only inappropriate with regard to injury, but also because the mating has usually already taken place and therefore fertilization of the bitch can no longer be prevented.
In cloven-hoofed animals , the glans hardly contains any swelling tissue; there are only smaller venous plexuses under the mucous membrane .
Cavernous bodies of the clitoris and periurethral erectile tissue
1) glans, glans clitoridis in the foreskin
2) erectile tissue ( corpus cavernosum clitoridis , the paired initial part unites to the corpus clitoridis and continues into the two crura clitoridis ; correspond to the corpus cavernosum penis )
3) clitoris thighs, crus clitoridis
4 ) Urethral opening
5) Atrial erectile bulbs correspond to the corpus spongiosum penis or corpus cavernosum urethrae
6) Vaginal opening , vestibulum vaginae
The following erectile tissue systems are described in women or should be named as accepted :
- Corpus clitoridis from the paired initial parts , crura clitoridis combined with the corpora cavernosa clitoridis to form the (“visible”) clitoris
- Glans clitoridis from the (the analogue of the Corpora cavernosa penis )
- Corpus cavernosum urethrae , to which, as an intravaginal continuation, the Halban'schen fascia , the Graefenberg zone and the anterior fornix erogenous zone, AFE zone for short , are included as additional erectile tissue.
The corpus cavernosum clitoridis of the clitoris behaves like the penile cavernous body and is quite extensive. The paired initial part unites to form the corpus clitoridis . It is important that the glans clitoridis is the anterior end of the corpus clitoridis , which corresponds to the corpora cavernosa penis and not the corpus spongiosum there, as is the case with the glans penis .
Cavernous bodies on the anus
The rectal corpus cavernosum of the anus (also called the internal hemorrhoidal plexus ) consists of a network of sinusoids ( blood vessels that, unlike veins, have no muscular wall parts), which are fed by the superior rectal artery . It is used for the fine closure of the anal sphincter (sealing function).
False cavernous bodies
Under the nasal mucosa ( lamina propria mucosae ) there is a dense network of blood capillaries, they open into a superficial venous plexus. This venous plexus is strongly formed in the area of the middle and inferior turbinate. A change in the volume of blood leads to a change in volume of the nasal interior spaces, which influences the flow of breathing air.
literature
- Alfred Benninghoff , Detlev Drenckhahn (Hrsg.): Anatomie. Macroscopic anatomy, histology, embryology, cell biology. Volume 1: Cell, Tissue, Development, Skeletal and Muscular System, Respiratory System, Digestive System, Urinary and Genital System. 17th edition, Urban & Fischer / Elsevier, Munich 2008, ISBN 978-3-437-42342-0 .
Web links
Individual evidence
- ↑ Hans Petersen: Histology and microscopic anatomy. Springer-Verlag, Berlin 2013, ISBN 3-64292-091-8 , p. 629 f.
- ^ Kim Wallen, Elisabeth A. Lloyd: Clitoral variability compared with penile variability supports nonadaptation of female orgasm. In: Evolution & Development. Volume 10, number 1, 2008, pp. 1–2 ( full text as PDF file ( Memento of the original from March 4, 2016 in the Internet Archive ) Info: The archive link has been inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice. ).
- ↑ Deborah Sundahl : Female Ejaculation & the G-Spot. Nietsch, Freiburg 2006, ISBN 3-934647-95-2 , p. 52 f.
- ↑ Helen E. O'Connell, John OL DeLanceyo: Clitoral Anatomy in Nullipardous, Healthy, Premenopausal Volunteers using unenhanced Magnetic Resonance Imaging. In: The Journal of Urology . June 2005, Volume 173, Number 6, pp. 2060-2063.
- ^ Helen E. O'Connell, A. Kalavampara, V. Sanjeevan, John M. Hutson: Anatomy of the clitoris. In: The Journal of Urology. 2005, Volume 174, Number 4, Part 1, pp. 1189–1195, doi: 10.1097 / 01.ju.0000173639.38898.cd , PMID 16145367 , ( PDF file; 973 kB ).
- ↑ Walther Graumann, Dieter Sasse: Compact textbook anatomy: in 4 volumes. Volume 1: General Anatomy. Schattauer, Stuttgart / New York 2004, ISBN 3-7945-2063-7 , p. 322.
