What Is the Anatomy of the Penis?

It is an important sexual organ for men, has sexual intercourse function, and has urination and ejaculation effects. The penis is mainly composed of two penile corpora cavernosa and one urethral cavernosum, and the outer bread is basal fascia and skin.

It is an important sexual organ for men, has sexual intercourse function, and has urination and ejaculation effects. The penis is mainly composed of two penile corpora cavernosa and one urethral cavernosum, and the outer bread is basal fascia and skin.

Shang Xuejun

The fifth deputy director of the Chinese Medical Association's Andrology Branch, the deputy director of the Sexuality Professional Committee of the Chinese Sexual Society, and the professor of andrology in the General Hospital of Nanjing Military Region. More details

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Erectile dysfunction foreskin is too long and phimosis

Authoritative content provides:

Chinese name

Penis

Foreign name

penis

Nature

Reproductive organ

Visiting department

Urology, Andrology

Sex

Male, male

The main function

Urination, intercourse and ejaculation

nickname

Penis

Anatomy of the penis

1. Divided into three parts: root, body and head. The posterior part is the penis root, which is attached to the inferior branch of the pubic bone, the sciatic branch, and the urogenital ridge. The central part is the penis body, which is cylindrical and drape over the anterior and lower part of the pubic bone. Called the outer urethral orifice, there is a circular groove at the junction of the head and body called the penis neck or coronary sulcus.

2. The cavernous body of the penis is a thin cylinder with two ends, one on the left and one on the back of the penis. The left and right are closely combined, extending forward, and the front end becomes thinner, embedded in the depression on the underside of the penis head. The posterior part of the cavernous body of the penis is separated, which is called the penis foot, which is attached to the lower abdominal and sciatic branches of the pubic bone on both sides. The urethral cavernous body is located on the ventral side of the penile cavernous body, and the urethra runs through its entire length. The middle part is cylindrical, the front end swells into the head of the penis, and the back end is called the urethral ball. The outer bread of each sponge body has a thick fibrous membrane, called the sponge white membrane. The inside of the cavernous body is composed of many cavernous trabeculae and cavities, which are actually sinus spaces communicating with blood vessels. When these cavities are congested, the penis becomes thicker and harder and erected; otherwise it becomes softer. The three corpora cavernosa are covered with shallow and deep penile fascia and skin. The film of the penis is thin and soft, full of extensibility. From the skin to the neck of the penis, it moves forward, forming a double-layered circular fold around the head of the penis. It is called the foreskin of the penis. The space between the foreskin and the head of the penis is called the foreskin cavity. On the ventral midline of the penis head, the skin folds that connect the foreskin to the outer mouth of the urethra are called foreskin laces. Foreskin is too long, too tight, infection, etc. can cause pain during sexual intercourse. Toddlers have long foreskins that cover the entire penis head. With age, the foreskin gradually retracts, and the foreskin mouth expands accordingly. If the foreskin covers the urethra, but can be turned up to expose the outer urethra and the penis head, the foreskin is said to be too long. When the foreskin is too small and the foreskin completely covers the head of the penis and cannot be opened, it is called a phimosis. In both cases, inflammation is easily caused by the stimulation of dirt in the foreskin cavity, and it can also be a factor inducing penile cancer. Excessive foreskin should be surgically removed to expose the penis head.

Histological structure of the penis

The blood supply to the penis comes from the dorsal penile artery, which is a branch of the external iliac artery. During sexual excitement, the three branches of the dorsal penis artery and its arterioles dilate, increasing perfusion blood flow; arteriovenous communication branches are blocked, venous return is reduced, and cavernous sinus congestion forms penile erection. The head of the penis is rich in nerve endings, so the penis belt, coronary sulcus, and urethral opening are particularly sensitive to external mechanical stimuli. The sexual sensory afferent nerve is the dorsal nerve of the penis. After reaching the low sexual response center of the iliac pulp, the parasympathetic nerve innervates the penile vascular smooth muscle and changes the vascular state. Lesions in the blood vessels and nerves of the penis can affect mating function.

Two natural states of the penis

1. When relaxing, drape below the pubic symphysis, mean length X = 6.55, S = 1.023, X ± 1.96S = 6.55 ± 2.046 (4.5 8.6) cm, maximum 10.6cm, minimum 3.7cm; The number X = 2.57.S = 0.255, X ± 1.96S = 2.57 ± 0.57 (2.06 3.08) cm, the maximum value is 4.3cm, and the minimum value is 1.9cm.

2. During the erection, the penis body takes the pubic symphysis as the axis to form an angle of 90 ° or more with the phallus, and the length increases by 1 to 2 times than normal, and the volume and hardness increase accordingly. It is generally believed that the penile swelling rate of the smaller penis is larger than that of the larger penis when it is relaxed, so it is rare that the penis is too small or too large to affect mating.

Penile- related diseases and treatment

1. Penile cancer is a common reproductive system tumor. It has ranked first in the incidence of male urogenital tumors in China in the 1950s and 1960s. In recent years, with the improvement of the living standards of our people and the continuous improvement of medical and health conditions, its incidence has decreased year by year.

2. Penile tumors are mostly penile cancers derived from penile epithelial cells. Phimosis and foreskin are too long are recognized causes of penile cancer. Penile cancer is a malignant tumor that can be prevented. Studies have found that circumcision in infants or children can effectively prevent the occurrence of this disease. If the foreskin is too long and can be turned up, regular cleaning can prevent cancer.

3. Treatment methods: At present, there are various treatments for penile cancer including surgery, chemotherapy, radiation therapy, laser, freezing, and photosensitivity. However, surgical removal of cancer is still the most important method, and partial penile resection is the most commonly used method. Operation. Because of its advantages such as simple surgery, reliable curative effect, partial sexual function, and standing urination, it is easy for patients to accept. Pathomorphological observations confirmed that some penile cancers, although cauliflower-like, grow large outward, but do not infiltrate deeply. Therefore, we believe that partial penile resection is a very reasonable and effective treatment method for stage and penile cancer. As long as the end of the penis is more than 2.0 cm from the edge of the cancer and the normal penis is maintained at 2.0-3.0 cm, it is not necessary Complete penile resection. Once metastasis is demonstrated, radiation therapy or secondary dissection should be performed.

4. Inguinal lymphadenopathy often occurs in patients with penile cancer, mostly due to secondary infection, and only a few are metastatic. Researchers believe that the principle of management is: At the same time as penile tumor resection, inguinal lymph nodes that have no signs of cancer metastasis should also be routinely biopsied. If positive, iliac inguinal lymph node removal should be performed within 2-4 weeks after surgery. For patients with suspected lymph node metastasis, do a frozen section of the lymph node before resection of the penile tumor. If it is positive and the patient can tolerate it, immediately perform a iliac inguinal lymph node removal. Inguinal lymph nodes are large and hard and there are signs of cancer metastasis. Even if the lymph node biopsy is negative, inguinal lymph node removal should be performed. If the sentinel lymphadenopathy is enlarged and the biopsy confirms the cancer metastasis, the operation scope should be expanded for inguinal lymphadenectomy. Patients who have not undergone inguinal lymph node clearance need to be closely observed for 3 months after discharge. If the local lymph nodes do not decrease but increase, pathological examination should be performed immediately. If they are positive, then inguinal lymph node clearance is performed. Lymphadenectomy is performed in patients with inguinal lymph node metastasis confirmed by preoperative lymphography or with metatarsal lymph node metastasis.

5. After the partial or total resection of the penis, the outer urethral stricture is complicated by wound infection, short urethral retention, or ischemic necrosis of the stump of the urethral cavernous body. Therefore, local immersion of antibacterial drugs and disinfectant is required before surgery. Waiting for preparation is necessary. During the operation, the indwelling part of the corpus cavernosum of the penis was placed on the dorsal side of the corpus cavernosum, which could increase the blood flow at the end. Shape to make the nozzle wide. Indwelling the F _18-20 silicone catheter can reduce local irritation, keep the urethra unobstructed, and prevent urine from soaking the incision. Removal of the catheter after the incision has healed has a positive effect on preventing the occurrence of urethral stricture. Penile cancer is a low-grade malignant tumor with a good prognosis. Therefore, patients with penile cancer should be treated as early as possible, and follow-up should be strengthened at the same time. If the disease recurs, they can be re-operated with appropriate radiotherapy or chemotherapy.