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Wednesday, January 23, 2013

Reproductive organs in animals, genitalia in animal, Sex glands in animal, Education gametes in animal

Female genitalia

The external female genitalia (vulva) include the labia , urogenital eve of the vagina, clitoris. The internal female reproductive organs include the vagina, uterus, fallopian tubes and ovaries.
female genitalia

Vulva

Vulva formed by two labia, which apparently covered with a thin skin with occasional gentle hair, but on the inside - mucosa. In the skin of the labia is a large number of sweat and sebaceous glands, and their thickness is circular muscle - szhimatel vulva. In the lower right corner of the gender gap is the clitoris (rudiment of penis male), consisting of the cavernous body.

Genitourinary

female genitalia-Genitourinary
Genitourinary eve vagina starts from the gender gap, channel it upward and forward and ends in the urethral opening, where it goes into the vagina. In the mucosa of the vestibule are small and large glands that secrete slimy secret during oestrus and hunting. Length of vestibule in cows and mares is 8-12 cm in pigs - 5-10 cm in sheep and goats - 2 - 4 cm in rabbits - 1-2 cm, females - 2 - 8 cm in cats - 2 - 4 cm

Vagina

female genitalia-Vagina 
Vagina starts from the opening of the urethra and ends at the cervix. It is located in the pelvic cavity in the rectum and is a muscular tube. Length of vagina in cows and mares is 22 - 30 cm in pigs - 10 - 12 cm in sheep and goats - 8-10 cm in rabbits - 4 - 6 cm, bitches - 4 - 8 cm in cats - 2 - 3 cm Eve vagina and vagina in females is sovokupytelnyy body and part of the birth canal to remove the fetus.

Uterus

female genitalia-uterus
The uterus consists of the cervix, body and horns. Cervix - thick-walled muscular tube. The mucous membrane forms numerous folds, which provide glands that produce thick, sticky mucus. The cervix is ​​tightly closed and opened only during estrus, hunting, childbirth and in certain diseases of the uterus.Cows cervix well detectable through the rectum in the form of solid strand length of 12.6 cm in mares - 5 - 7 cm in pigs - 8 - 20 cm in sheep and goats - 4 - 8 cm, and rabbits - 1 - 1.5 cm (two cervical, each horn of the uterus opens his neck - double uterus) in females - 1.5 - 2 cm in cats - 1 - 1.5 cm body cancer in animals developed differently. Cows has a length of 2 - 4 cm in mares - 8 - 15 cm (serves plodovmestilischa with horns of the uterus) in pigs - 5-10 cm in sheep and goats - 2 - 4 cm, females - 3 - 4 cm in cats - 1.5 - 2 cm uterine horn - even education officials plodovmestilischa. Their length (in non-pregnant) in cows is 16 - 20 cm in mares - 18 -30 cm in pigs - 100 - 200 cm, sheep and goats - 10 - 12 cm in rabbits - up to 10 cm, bitches - 10 - 18 cm in cats - 5 - 7 cm on the lining of the uterus in both horns only in ruminants is karunkulov (multiple placenta): the cows - 80 - 120 pcs., in sheep and goats - 88 - 110 pc. In pregnancy they increase in size from a pea to a hen, goose eggs and more.

Oviduct 

paired organs in the form of tubes (diameter 1 - 1.5 mm), length in cows, mares and pigs 25 - 30 cm in sheep and goats - 9-18 cm in rabbits - 6 - 9 cm, bitches - 5 - 12 cm in cats - 4 - 5 cm

The ovaries (gonads)

female genitalia-ovaries
paired organs that perform two functions: reproduction - the formation, growth and development of eggs and endocrine - hormone synthesized folliculin (estrogens - estrone, estradiol, estriol). Ovaries - cancer, deprived of their excretory ducts. Ovum goes from the ovary after bursting mature follicle (Graaf bubble), and in its place formed corpus luteum, which produkuvatyme hormone progesterone (prozhestin). The size and weight of the ovaries vary greatly depending on the age, type females, the stage of the sexual cycle. Cows ovaries are oval (right slightly more left). They are located at the level of the ilium in the pelvic cavity, and during 
female genitalia-ovary

pregnancy fall into the abdominal. In mares ovaries bobovydnoy form on the underside with ovulation fossa, which revealed mature follicles. Externally, except ovulyatsyonnoy fossa, they are covered with serous membrane. Located in the abdominal cavity.Pigs ovaries are oval-shape rolling hills, located in the abdominal cavity. In sheep and goats rounded, located in the pelvic cavity during pregnancy - in the belly. In rabbits - elongated oval, located in the abdominal cavity. In dogs and cats - oval, located in the abdominal cavity.At the exit of the ovary shows two layers: cork - follicle, which contains follicles of varying degrees of maturity and brain - vascular, consisting of a dense network of blood vessels and nerves. Male sex organs consist of the penis, prepuce, scrotum, testes and ovaries, and adnexal semyaprovodov gonads.

Male genitalia

Penis

Male genitalia-penis
The penis  consists of legs, top, body and head. Starts penis Bouguereau gluteal pelvis two legs.Confluence forms the root of the penis legs that goes into the body. The body of the penis head ends, which provided plenty of nerve endings. In the bull, boar, ram and goat penis forming S-shaped bend straightens during erection. The basis of the penis consists of three cavernous or cavernous, body. In bull penis with a pointed tip on the head is a bunch of spit that causes during ejaculation cephalic nearly 360 ° in the allocation of sperm.
Male genitalia
 In the stallion he is highly developed in thickness, head to erect mushroom is education (diameter 15 cm), the length of the penis during erection 50 - 80 cm boar penis in the final part of the spiral curled in length with an erection up to 80 cm sheep and goat - cylindrical ends offshoot urinary channel length of 3 - 4 cm, length of the penis 35 - 45 cm in rabbit penis in the form of a cylinder length of 2.5 - 4 cm in males - conical, in front of his of embedded bone length 8-10 cm in cats in the penis bone embedded length of 2 - 3 cm in the form of a cross. All the male head of the penis at rest is in the cavity of the prepuce.

Scrotum

Male genitalia-Scrotum
Scrotum designed to accommodate the testes and their appendages. In it, the temperature at 3 - 5 ° C below the temperature of the abdominal cavity, it is necessary to fully spermioobrazovaniya and preservation of gametes.

Testes

Male genitalia-Testes
Testes and ovaries are located in Semennykovoy bag. They serve a reproductive function - spermatogenesis and endocrine - produce the hormone testosterone. Testis (right and left) has albuginea, from which the thickness of the parenchyma semennyka veeroobrazno depart partitions, dividing it into segments, where the convoluted tubules, which empty into the straight tubules that constitute a network semennyka. From her depart spermiovynosyaschie tubules that pass into the canal of the epididymis semennyka. In appendage semennyka distinguish the head, body and tail. Channel tail appendage expands, becomes semyaprovod.

Spermatic cord

Male genitalia-spermatic cord
Seed tube is part of the spermatic cord. Through the inguinal canal, he falls into the abdominal cavity and reaches the surface of the bladder, forming capsules (they are not in boar, dog and cat). Here, both semyaprovoda merge into a common excretory duct, which empties into the urethra, then the channel is called the urogenital. In the urinary channel flow duct adnexal gonads.

Sex glands

sex glands
By contracting genital glands are vesicular, prostate, bulbous (Cowper). In dog no vesicular and bulbous glands. Accessory sex glands produce secret dilutive lot of sperm, which nourishes and stimulates their movement and protects against residual urine in the urinary channel and in the genital tract of the female vaginal and uterine mucus.
Sexual and physiological ripeness animals - the ability of females and males to reproduce offspring. With the onset of puberty genitals reach full development.

Sex glands in females

Sex glands in females
Sex glands in females produce gonadotropic hormones: follicle, lyuteoniziruyuscheho, luteotrophic; ovaries - estrogen (folliculin) and corpus luteum - progesterone. Hormones rise in female sexual cycle - folders, sexual arousal, hunting and ovulation, discharge eggs capable of fertilization.

Sex glands in males

Sex glands in males
In males under testosterone appear sexual reflexes - sexual attraction to females, penile erection, ability to have sexual intercourse (coitus) and mature ejaculation of sperm.


Puberty in animals

of all kinds is earlier than end the growth and development of the whole body - the body physiological maturity (Table).Grid. Terms offensive sexual and physiological maturity of animals
Sex glands
Type of animal, sexual maturity, physiological maturity(years):
Cattle:                    12.8                       16-18
Horse:                    12-18                       3-5             
Pig:                        08.05                      10.12
Sheep, goat:            6.8                        12-18
Rabbit:                    4.5                         5.8
Dog:                        8.6                        12-24
Cat:                        05.04                      12.10
Animals (females and males) are used for the purposes of reproduction at the conclusion of the processes of the body, reaching 70% of body weight (usual adult animals of this breed and species), and of a certain age. Premature inseminated females (the age of maturity of the body) and the long absence of their insemination after reaching physiological maturity of the body are undesirable, because they can lead to infertility.

Education gametes


Education of gametes
Education and the allocation of gametes (eggs in females and sperm in males) suitable for fertilization, beginning with the onset of puberty and continue until old age.

Oogenesis

Oogenesis the process of education, development and maturation of the female reproductive cells (oocytes) in the ovaries (Fig.).

Education of gametes-Oogenesis




Rice. Ovary 1 - germinal epithelium, 2 - primary follicles, 3 - growing follicles, 4 - mature follicles, 5 - egg




Oogenesis takes a long time, starting from the formation of the cortical layer of primary ovarian follicle to its maturation after ovulation and ends in the oviduct. In Ovogenesis (Oogenesis) distinguish three stages: reproduction, growth and maturation. Ovum consists of protoplasm, nucleus and membrane. It is one of the largest cells.
Diameter her in female mammals is from 0.12 to 0.145 mm. Egg volume more sperm in 10 - 20 thousand times the length - 2 times. The egg was opened in 1827 Russian scientist KE Baer. 
Education of gametes-Oogenesis
The animals are suitable for fertilization only egg maturation process which lasted from 2 to 20 pm With the development and maturation of follicles inside their layer (directory) produces estrogens that act on sexual center and genitals, which contributes to the females sexual dominant ( manifestation of estrus, sexual arousal, hunting and ovulation). Size mature follicle reaches a diameter of 1-2 cm in cows in mares - 4 - 6 cm in pigs - 0.5 - 1 cm in sheep and goats - 0.3 - 0.8 cm, rabbits, and bitches cats - 0.2-0.3 cm to stage large follicles develop some mature follicles, as estrogens inhibit production of follicle stimulating hormone (FSH). Reduced levels of FSH, in turn, slows the growth and maturation of small follicles undergoing atresia (zapustevaniyu).

Spermatogenesis

Education of gametes-Spermatogenesis
Spermatogenesis the process of formation and development of male germ cells - sperm. Spermatozoa formed in males in seminiferous tubules of the testes with germ.
In Spermiohenez unlike Ovogenesis distinguish four stages: reproduction, growth, maturation and formation. Sperm is strongly elongated in length (from 54 to 72 microns) cell. Length sperm does not depend on the type of animal. Open sperm in 1677 range. Outside sperm covered with a thin but strong sheath that the chemical composition is similar to the keratin of skin animals. Mature sperm are on the surface negative electric charge, which prevents them bonding (agglutination). Spermatozoa move only against the current of fluid (reotaksis) at a rate of 3 - 5 mm / min. The whole process from the first division Spermiohenez original cells until sperm in appendage semennyka lasts 35 - 55 days. One day in the testes produced 5 - 7 billion sperm. The tail of the epididymis semennyka is a kind of biological repository of spermatozoa through the epididymis secretions acidic reaction (pH 5.7 - 6.5) sperm pass into a state of suspended animation. The concentration of spermatozoa in the tail of the epididymis in males of all species in an average of 4-5 billion in 1 ml. The whole process of spermatogenesis is dependent on the state of the male, his food, maintenance, external and internal factors.
Education of gametes-Spermatogenesis
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