Frog Urogenital System Short Notes | Free Biology Notes

In this article we will discuss about the frog urogenital system

Frog Urogenital System

• The urinary and reproductive systems are linked and collectively referred to urinogenital system
• The frog Urogenital system responsible for urine excretion and reproduction
• Frogs are ureotelic animals because urea is their main excretory product
• Frogs have separate sexes, so they are dioecious
• Male and female frogs can only be distinguished externally during the breeding season
• Males developing a copulatory or nuptial pad on their first forelimb digit
• Males also have vocal sacs
• Male and female frogs have the same excretory system, but their reproductive structures are different

Male Frog Urogenital System

Kidney

• Both kidneys are elongated, compact, flattened, and dark red
• Each kidney consists of many functional and structural units called nephrons or uriniferous tubules
• Tadpole kidneys are pronephros, whereas adult kidneys are mesonephros

Urinary bladder

• It is a large, thin walled and bilobed structure
• Present ventral to the rectum. It stores urine

Ureter

• Ureter or the urinogenital duct occur in pairs
• The ureters opens into cloaca and helps in passing the urine and sperm

Testis

• The testis are attached to kidneys by mesorchium
• Testis is composed of a large number of seminiferous tubules
• The wall of seminiferous tubules is made up of germinal epithelium, which forms sperms by spermatogenesis

Vasa efferentia

• Emerges from the testis and are 10-12 in number
• They pass through mesorchium and entering the kidney and opening into the bidders canal
• Collecting tubules of the kidney and the bidders canal communicates with the ureter

Cloaca

• Small chamber mediating to pass urine, faeces and sperms to the outside
• The ureter and urinary bladder opens into the cloaca

Female Frog Urogenital System

Kidney

• Both kidneys are elongated, compact, flattened, and dark red
• Each kidney consists of many functional and structural units called nephrons or uriniferous tubules
• Tadpole kidneys are pronephros, whereas adult kidneys are mesonephros

Urinary bladder

• It is a large, thin walled and bilobed structure
• Present ventral to the rectum. It stores urine

Ureter

• Ureter occur in pairs
• The ureters opens into cloaca and helps in passing the urine and sperm

Ovary

• It is a paired structure found near the kidneys
• Ovary covered by fold of peritoneum known as the mesovarium
• They produce ova through the process of oogenesis
• A mature female can produce between 2500 and 3000 eggs all at once

Oviducts

• They are paired and found on each side of the ovary
• These ducts open separately into the cloaca

Cloaca

• Small chamber mediating to pass urine, faeces and ova to the outside.
• The ureter and urinary bladder opens into the cloaca

Copulation

• Copulation takes place in water during breeding season
• Male produce croaking sound with the help of vocal sacs
• The croaking is a mating call for the female frogs
• The male frog rides over the female frog and embraces it.
• The male frog holds the female frog firmly by its forelimbs and nuptial pads
• The couple remains in this condition for 2-3 days
• At this stage orgasm female discharges a large number of eggs in water and same moment discharges its sperms over the eggs falling in water.
• The two animals separate from each other on completion of this process

Fertilization

• The fertilisation is external, taking place in water
• In the fertilisation sperm and ova fuse together to form zygote
• The eggs hatch into tadpoles which later on undergo metamorphosis to develop into adults