The Excretory System
- Osmoregulation: the control of tissue water balance, and the elimination of excess salts and urea.
- Blood enters the kidney through the renal artery and exits through the renal vein.
- Kidney is made up of microscopic tubules, blood vessels, and nephrons.
- Nephron consists of Bowman's capsule, a proximal convulted tubule, the loop of Henle, a distal convulted tubule and a collecting duct.
- Glomerulus: a ball of capillaries surrounded by Bowman's capsule, where blood is filtered as water and waste into the Bowman's capsule.
- The hypertonic urine passes into the collecting ducts, which empty into the renal pelvis, an expanded portion of the ureter into the kidney.
- In the fetal pig the ureter narrows into the small allantoic stalk in umbilical cord.
- In male pigs the urethra leads into the penis.
- In female pigs the urethra joins the vagina forming the vaginal vestibule.
The Male Reproductive System
- Consisting of gonads, ducts and glands.
- Testes (male gonads) produce sperm and secrete testosteron and other male sex hormones.
- Sperm pass from testes into epididymis where they mature and stored.
- When ejaculation, sperm passes from the epididymis through the ductus deferens (vas deferens) to the urethra which leads to penis.
- Semen are secretions added from seminal vesicles, prostate gland and bulbourethal glands, that contains sperm, fructose, amino acids, mucus, and other substances that produce a favorable environment for sperm survival and mortility.
- Preputial Orifice: urogenital opening.
Pathway of sperm
- Testis: sperm and testosterone production.
- Epididymis: storage and maturation of sperm.
- Vas (ductus) deferens: transport of sperm and addition of seminal fluid.
- Urethra: transport of sperm (semen) and urine.
- Penis: transport of semen to female reproductive system.
The Female Reproductive System
- Consists of ovaries, short uterine tubes, the uterus, the vagina and vagina vestibule (in the pig fetus).
- Ovary: produces egg and sex hormones.
- Oviduct: conducts egg to uterine horn.
- Uterine: house developing young.
- Vagina: organ of copulation and birth canal.