The Digestive System
What are the main functions in digestion of the
a) mouth
b) stomach
c) small intestine
The mouth takes in the food and uses the teeth and the salivary glands
do break down the food so it could move onto the next phase. The teeth
chew food while the salivary glands, liver, bile duct and pancreas
produce digestive juices to break down food.
The stomach is a L shaped, organ situated on the left side of the
abdominal cavity beneath the diaphragm. At either end of this organ is
a sphincter muscle which contracts and relaxes to control the movement
of food in and out of he stomach. The stomach churns the food and
releases gastric juices to help break it down. The gastric juices
contain hydrochloric acid and enzymes such as pepsin. Hydrochloric
acid kills any harmful bacteria and helps to dissolve the food. Pepsin
begins the digestion of protein by breaking it down. Food can stay
within the stomach for about 5 hours and leaves in a liquid form
called chyme.
The small intestine is over 6 metres long and is the place where most
of the nutrients are absorbed. There are three parts to the small
intestine. They are the duodenum, the jejunum and the ileum. The
inside of the small intestine is covered by millions of tiny finger
like projections called villi. The shape of the villi ensures a large
surface area so that the digested food can be absorbed quickly.
What is peristalsis and where does it occur?
Peristalsis is the process of food being propelled downwards, this
takes place in the oesophagus. Peristalsis is muscular contractions
that squeeze and relax the walls of the oesophagus.
Bri...
... middle of paper ...
...
* Excess amino acids are broken down and converted into urea
* Drugs and poisons are broken down
* Antibodies and antitoxins are made
What organs make up the urinary system?
The urinary system are made up of the following organs,
* The kidneys/renal organs
* The ureter
* The bladder
* The urethra
What is the difference between a male and female urethra?
The male urethra is a common canal for the urinary system and
reproductive system and is 18-20cms long. The female urethra. In the
female it serves as the urinary system only and is 4cm long.
What is the main function of the urinary system?
The main function of the urinary system is to keep the body in
homeostasis (balanced body). The system also helps to control the PH
of the blood and regulate blood pressure.