The structure of the digestive system in the human body, and its importance to achieve efficient performance in sports
The digestive system is a group of organs that breakdown chemical components of food into tiny nutrients which are then absorbed to generate energy for the body. The digestive system contains :
- Mouth
- Pharynx
- Oesophagus
- Stomach
- Liver
- Gall bladder
- Jejunum
- Ileum
- Colon
Functions of the digestive system are :
Ingestion – eating Digestion – breakdown of food Absorption – extraction of nutrients from food Defecation – removing the waste products
The buccal cavity :
Food is chewed by teeth, turned and mixed with saliva, during which the sensations of smell and taste stimulate the salivary glands.
The salivary glands :
Lubricates the food which enables it to be swallowed, ptyalin starts breakdown of starch
The pharynx :
Receives softened food mass and initiates swallowing, epiglottis moves over trachea and prevents food from entering the windpipe.
The esophagus:
Food is moved in wave like motion called peristalsis caused by contraction in longitudinal and circular bands.
Anti-peristalsis where the movement occurs upward is the reflex action of vomiting and is helped by abdomen and diaphragm.
The stomach :
Acts as reservoir for food, between 2 to 6 hours. Food is mixed with various hormones, enzymes which begins the digestion of protein, other chemicals are secreted further down the tract.
It has a capacity of 1 litre and varies in shape. The stomach is impermeable to most substances. Pylorus opens at regular intervals allowing food to enter the small intestine.
The small intestine:
It is 7 meters long in an adult, and it consists of duodenum, jejunum, and ileum. There is a large lymph and blood supply which is ready to transport nutrients to the rest of the body.
The pancreas :
Aids in the process of digestion. Release insulin directly into the blood stream for controlling blood sugar levels.
The liver :
Secretion of bile to gall bladder; Carb, protein and fat metabolism; Storage of glycogen; Ingestion of worn out RBC, WBC, and bacteria.
The gall bladder :
Emulsifies fat which makes it easier to breakdown.
The large intestine :
1.5 m long and consists of caecum, appendix, colon and rectum.
ACHIEVE EFFICIENT PERFORMANCE IN SPORTS :
As we know food after ingestion and digestion is stored in the liver’s glycogen stores, proper planning of food before an event can all the difference as once the glycogen in the blood is used the brain send signal and the glycogen stores in the liver are used. Proper diet before any meet or event will ensure that all glycogen stores are full and hence energy is always available which in turn increases the performance of the athlete.
Not being careful or selective with our food can cause nauseating, vomiting, allergic reactions, feeling heavy, food poisoning, diarrhea all of which will affect the performance and some time may even lead to being admitted in the hospital.