Testes – Anatomy and Functions
Testis are one of the major organs in endocrine system. As testis are able to secrete hormones, that is why they lies under endocrine system. They are main sex organ for male. Testis are present in the body in a pair. That is why it is often called as pair of testicles. Sometimes testis are often call as testicles. Testis are responsible for the spermatogenesis process. Testis can able to secrete the Testosterone hormone which is responsible for sexual development. Also, along with testis there are many other sexual organs are present. Like Prostate Gland, Urethra, Penis etc. But they are not mainly associated with sexual development or sperm production. Testis often command the Central Nervous System for any sexual behaviors.
Location of Testis
The testis is present only in the male body. They are situated outside of the abdomen cavity. They are present in Scrotum. Scrotum is a sac like structure. It is made with skin. Testis within scrotum, hangs outside of the body. But when a child takes birth, his Testis is not there in the Scrotum sac from the beginning. It is situated in the abdomen cavity during its early stage. With the time, it gradually descent down to the Scrotum sac & present there, for the rest of its life. Scrotum not only protects the testis but also, they help to produce the sperms. For producing sperms testis needs a cooler temperature than body normal temperature. That is why testis is found hanging outside of the body. Also, the scrotum helps to regulate & maintain the temperature inside the sac. During summer season, when the outside temperature rises rapidly, then scrotum expand its size to make the temperature cooler. But during winter season, we witness opposite action. In winter temperature outside falls down in a rapid way. That amount of low temperature can prevent sperm production. That is why in winter season, the scrotum shrink itself and make the testis available nearer to the body. As the body normal temperature will help the testis to maintain its normal temperature during winter season. For these reasons the location of testis are very important.
Structure of Testis
The testis has oval shaped structure. The normal size of testis can compare with a medium size almond. They have dimension like 4 cm to 5 cm in length & 2 cm to 3 cm in width. Generally, we find the left testis to hang slightly lower than the right one. The structure of Testis can be divided into two parts. Some of them are situated outside of the Testis but play a vital role in it. Some of them are located inside of the testis.
- Anatomy: It is a tube present outside of the Testis. It is very narrow tube which connects the rear of testis along with the Vas Deferens. It is very tightly collied with itself. The Epididymis can be divided into three parts further, Head, Body, and Tail. The body is situated on the top of the testis. The body is the long part of Epididymis. It connects the head to the tail itself. And the tail connects to the Deferent Duct.
- Functions: It helps to store the sperm. In the Head part of the Epididymis, the sperm stores for some time. In the body part of it, the sperm becomes mature. And the tail part helps the sperm to move to the Vas Deferens & then to the Ejaculatory Duct.
- Disorders: Though, disorder in the Epididymis is very rare in case. But one disease can be noticed. It is called Epididymitis. In this disease, inflammation can be observed. This disease occurred by Bacteria infection. Often this disease happens due to sexually transmitted infection.
- Anatomy: Inside the testis there is nothing much complex structure is present. Inside testis, there is only one type of structure. They are Seminiferous Tubules. They are coiled tubes present coiled like structure, completely occupied all the major areas inside of testis. There are nearly 250-300 Seminiferous tubules are present in each testis. Seminiferous tubules are lined with epithelium. The epithelium is a layer of tissue. In the epithelium we find Sertoli cells. In between each Seminiferous tubule, there is some intratubular space are present. Inside those spaces, there are some special cells that can be found. They are called Leydig cells.
- Functions: Seminiferous Tubules are responsible for the spermatogenesis process. Inside there, sperm produces. Also, along with that Sertoli cells helps to regulate the sperm production process. Leydig cells produce the hormone which is necessary for sexual growth. Also, it helps to increase the production of the sperm inside the Seminiferous Tubules.
- Disorders: Disorder related to Seminiferous Tubules are not those diseases by which human effected due to their lifestyle. But disorders which are related with Seminiferous Tubules often comes naturally. Like, such as Sertoli Only Syndrome, Hypogonadism, etc. In this type of disorder, there is no such type of cause. Like for Sertoli Only Syndrome, there is only Sertoli cell present in the Seminiferous tubules. Leydig cell are not present in this type of cases. Here as a result, spermatogenesis process will not take place smoothly. For Hypogonadism, synthesis of Testosterone stops due to Testicles problems. Or sometimes, Brain sends some wrong messages to the Testicles which can prevent the production of Testosterone.
- Anatomy: Rete Testis is basically a network like structure made with tubules. It is situated where all Seminiferous Tubules are connected to each other. Basically, it the structure which is responsible for the connection of Seminiferous Tubules. Rete Testis is formed with a single layer of epithelial cells. Along with the cells there are connective tissues are present. In each of the Epithelial cells, there is a single Microvilli present. These cells are cuboidal in shape.
- Function: The main function is to collect all the sperms which produced at the Seminiferous Tubules. They collect the sperms & transport them to the Efferent Ductulus. Also, along with this another main function is the absorption of sperms. When the sperms are produced in the Seminiferous Tubules they are in dilute form. Rete Testis reabsorbs the luminal fluids of sperms. Thus they become more concentrated at this stage. Nearly, 95% of fluid are being absorbed.
- Disorder: Disorders in Rete Testis are very much rare. But one case can be noted down. The disease is called Cystic Dysplasia. In this disease testicular tumor can be developed at the Rete Testis. There is no such reason why this disease causes. Ultrasonography can help to treat this disease.
- Anatomy: The Efferent Ducts are like the connection bridges in between the Rete Testis & the Epididymis. There are mainly two types of Efferent Ducts can visualise. They are multiple-entry & single-entry ducts. Multiple entry ducts are present in large mammals like in Human. It is the case where 10 to 15 ducts enter the Epididymis. They enter in a huge size that those ducts occupy the 1/3rd portion of the head of Epididymis. And in another same, all the Efferent Ducts combine & make a single duct which only enters to the Epididymis. This type of structure can visualize in rats & other small mammal. They are made with ciliated & non-ciliated cells.
- Function: Efferent Ducts also performs the same task as Rete Testis. They also help to absorb the liquid in the sperms & make them more concentrated. All the cells are absorptive in nature. Efferent Ducts reduce the water presence & transfer the sperms to the Epididymis.
Layers of Testis
The testis has three layers. All of these layers perform only one major task. They are present to protect the testis from any injuries.
- Tunica Vaginalis: it is the outer most layer of Testis. Further, it can be divided into two parts, Parietal & Visceral. The visceral layer overlaps with the Tunica Albuginea. And the Parietal layer is present in the below Scrotum layer. In between the Parietal layer & the Scrotum layer, there is some fluid present which reduces the friction in between Scrotum & Testis.
- Tunica Albuginea: This is the middle layer of the Testis. This is also made with connective tissues. This layer further extends into the Testis & made some partitions inside the Testis. In each of these partitions, there are Seminiferous Tubules are present. Tunica Vaginalis covers the Tunica Albuginea.
- Tunica vasculosa: It is the innermost layer of the Testis. It is made with connective tissues. In this layer, blood vessels are present in a high amount. Tunica Albuginea covers the Tunica Vasculosa layer. It transfers the blood supply to the Tunica Albuginea & to the Testis. Also, it is most important as it mainly protects the Testis internally.
Importance of Testis
The testis is not only an endocrine organ but it is a sexual organ first. For male, testis is only one sexual organ. Without it, human developments can’t visualize. Before coming to the adulthood of humans, there may slight some differences between male & female. When a child takes birth, it is difficult to decide its gender. But as they grows up their sexual character starts developing. As males, they start developing a high-pitched voice, bread, mustache, etc. Even these characteristics can visualize before coming to their adulthood. Similarly, for female, they develop larger breasts, menstrual cycle etc. with their growing ages. All these characters are developed by sexual hormones. For male, only one sexual hormone is present that is Testosterone. Without it now sexual development can produce for a particular individual. If that happens any time, there will be no difference between male & female. Due to disorder with sexual organs many males develop some symptoms which are related with female sexual characters. That is why testis plays a vital role in our daily life.
Functions of Testis
Secretion Of Testosterone
Testis is mostly important as it can secrete the Testosterone hormone. It is the only sexual hormone that can be found in the male body. This hormone is highly important for our daily life. When a child takes birth, his testis is placed as inactive in form. But as he grows up testis starts working. Males have some reproductive characteristics. Like men develop bread, mustache, etc. Male has the ability to grow long hair on their body. As well as their muscular systems develops in such a way that males appear more muscular than the females. All these developments are done with the help of Testosterone. This hormone escalates the presence of male reproductive characteristics with the rising age of any male. After adulthood, the reproductive characteristics develop themselves in a vast way.
Commanding The Central Nervous System(CNS)
Central Nervous System is the main working network in the human body. CNS is made up of the Brain & Spinal Cord. The testis has the ability to command the Brain. Depending upon the need, Testis may send particular messages to CNS. This message helps to display the reproductive behavior of certain individuals. As Testis is the main sex organ in male, it helps to regulate the sexual behavior of the males through commanding the Central Nervous System.
Synthesis Of Sperm
The testis is the place where the synthesis of sperm takes place. The process by which sperm synthesis is called Spermatogenesis. Sperm is only Gamete, present in male body. They have DNA in their head-like structures. Synthesis of sperm takes place in the Seminiferous Tubules, which are situated in the testicles. At a time, males ejaculate 100 million sperms.
Regulating The Secondary Sexual Organs:
Testis is required for regulating secondary sexual organs in male. Secondary sexual organs are like the prostate gland, seminal vesicles, urethra, and penis. Testis helps to maintain their daily routine. Also, as they are all internally connected Testis can work as like “Brain” of Sexual Organic System of Male.
Disorders with Testis
Due to some external hurt or some internal hormonal problem testis can develop some disorders. But internal hormonal problems are rare cases. In case, there are disorders with Testis, some common symptoms are
- A pain can able to feel in Scrotum or nearer area
- Swelling can be a symptom in this type of case
- Also, pain in the lower abdomen area is a symptom of Testis disorder
- Nausea is the major issue related to this type of case.
Frequently Asked Questions
Question 1: How many layers are there inside of Testicles?
Inside of Testicles, there are mainly three layers. They are
- Tunica vasculosa: They are the innermost layer of the Testis. It is made with bold vessels & connective tissues
- Tunica Albuginea: This is the middle layer of the Testis wall. They are made with tissues.
- Tunica Vaginalis: This is the outermost layer of the Testis. It performs as the protective layer of the Testis.
Question 2: What is Gubernaculum?
The gubernaculum is the fibrous cord that is present in the Scrotum sac. It connects the bottom of the Testis with the bottom of the Scrotum. It helps Testis to stay in the same position.
Question 3: What is Orchidopexy?
Orchidopexy is a surgical movement. With time, Testis comes down to the Scrotum. But due to some health issues, in rare cases, it doesn’t come down gradually. That time with the help of surgery Testis was placed at the Scrotum.
Question 4: What do know by Cremasteric Reflex action?
Cremasteric reflex action is found in males. If for some reason, when the inner part of the thigh is being stroked then this reflex can visualize. In this case, the Cremaster muscle will contract. Hence, the Testis will pull up towards the inguinal canal.
Question 5: Are the sperms being stored at Testicles? If Yes, then where?
Yes, Testis is not continuously made sperms. They also store it. For storing purposes, one special duct is being used. This is called Ductus Deferens. Sperms are stored in the proximal portion of this duct. Once needed, this duct ejects the sperm outside of the body.
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