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Peculiarities of structure, development of organs of the digestive system. The structure of the wall of the different portions of the intestine tube. Anomalies of the development

The stomach of some herbivore has several cham-
bers. In contrast, the intestine in
carnivores is much shorter, the large intestine is less developed, and the
stomach always consists of a single chamber. In structure of the digestive
tract, omnivores occupy an intermediate position. Main is an omnivore.

The entodermal primary alimentary canal is subdivided into three
parts: (1) antertor (the foregut), from which develop the posterior part of the
mouth, the pharynx (except for the superior area close to the choanae which
is of ectodermal origin), the oesophagus, the stomach, and the initial part
of the duodenum (the bulb); (2) middle part (the midgut) communicating with
the yolk sac and developing into the small intestine, and (3) the posterior
part (hindgut), from which the large intestine develops. Some histologists
claim that the portion of the foregut up to the junction with the stomach
has a cutaneous-type epithelium, which explains the sharp borderline where
the epithelium of the oesophagus is continuous with that of the stomach which
is derived from the entoderm.

3 membranes of the primary alimentary canal, mu-
cous, muscular, and connective tissue, acquire different structure in the dif-
ferent parts of the canal.

Anomalies: Esophageal atresia and fistula are malformations in which the natural breathing tube, known as the trachea, and the feeding tube, called the esophagus, are improperly formed. Tracheoesophageal fistula is a small opening between the windpipe and the esophagus, Intestinal atresias are malformations of the intestines in which a segment of bowel is very narrow or is disconnected from the rest of the GI tract. Hirschsprung’s disease is a condition in which nerve cells called ganglia have not formed on the inner wall of the bowel. This causes the bowel to contract and not relax, obstructing the lower intestine.

20. Peculiarities of structure and development of organs of Urinary organs. Functional anatomy and embryone development of genital (male+female) organs.

Urinary organs kidney (excreate urine) and uterina (uteres, urinary bladder, urethra)

The kidney (ren, Gk nephros) is a paired excretory organ producing the
urine The kidneys are situated on the posterior abdominal wall
behind the peritoneum on either side of the vertebral column on the level
of the last thoracic and upper two lumbar vertebrae The
right kidney is a little lower than the left, by 1.0-1.5 cm on the average
(depending on the precure exerted by the right lobe of the liver). The upper
end of the kidney reaches to the level of the eleventh rib, the lower end is
3-5 cm from the iliac crest. Individual variations are encountered, however,
in the position of the kidneys: upper boundary often rises to the level of the
superior border of the eleventh thoracic vertebra, the lower boundary may
descend for the length of half or a whole vertebra. The kidney is bean-shaped
.

The male reproductive system is a network of external and internal organs that function to produce, support, transport, and deliver viable sperm for reproduction. Prenatally, the male sex organs are formed under the influence of testosterone secreted from the fetal testes; by puberty, the secondary sex organs further develop and become functional. Sperm is produced in the testes and is transported through the epididymis, ductus deferens, ejaculatory duct, and urethra. Concomitantly, the seminal vesicles, prostate gland, and bulbourethral gland produce seminal fluid that accompany and nourish the sperm as it is emitted from the penis during ejaculation and throughout the fertilization process

The female reproductive system is a complicated but fascinating subject. It has the capability to function intimately with nearly every other body system for the purpose of reproduction.

The female reproductive organs can be subdivided into the internal and external genitalia (see the images below). The internal genitalia are those organs that are within the true pelvis. These include the vagina, uterus, cervix, uterine tubes (oviducts or fallopian tubes), and ovaries. The external genitalia lie outside the true pelvis. These include the perineum, mons pubis, clitoris, urethral (urinary) meatus, labia majora and minora, vestibule, greater vestibular (Bartholin) glands, Skene glands, and periurethral area.

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