Term 4 Flashcards
What are the main parts of the digestion tract itself?
The mouth pharynx, esophagus, stomach, small intestine, large intestine, rectum and anus.
Accessory organs: tongue, salivary glands, pancreas, liver, and gall bladder.
What do the digestive systems ultimately provide?
It provides the nutrients required for all metabolism including growth, repair, and maintenance of tissues.
What is the urinary system?
The digestive system interacts with the urinary system. Kidneys excrete toxins and the breakdown products of hormones which have been metabolised by the liver.
What does the digestive system have to do with with the cardiovascular system?
The digestive system absorbs iron required for synthesis of hemoglobin, and water for maintenance of blood volume.
What does the respiratory system have to do with the respiratory system?
The respiratory system provides oxygen to the organs of the digestive system and disposes of carbon dioxide produced by cellular respiration.
What are vitamins?
Vitamins are a group of complex organic substances that are essential in small amounts for the normal functioning of the body. With the exception of niacin and vitamin c the body cannot manufacture this substances and we must obtain them from food.
What role does protein play in the diet?
Proteins supply the body with amino acids hunch are then reassembled by the body into new proteins. Without sufficient protein the body breaks down muscle tissue to retrieve amino acids.
What is the role of carbohydrates in the diet?
Carbohydrate such as glucose is the main energy source for the body. Entrain and other nervous tissue require glucose as an energy source.
What is glycogen?
Glycogen is the main energy storage compound for mammals? It is more water soluble than starch and is found in mainly muscle and liver cells, which are both centres of high metabolic activity.
What are lipids?
Lipids are a group of organic compounds with an oily, greasy or waxy consistency (fats).
What are the three features of the oral cavity and what do they do?
Teeth: are structures specialised for masticating (chewing) food.
Tongue: along with the lower jaw it moves food around the mouth to aid physical break down by chewing.
Salivary glands: add saliva during chewing to moisten food and aid in digestion.
What is the role of the salivary glands?
They are located towards the rear of the oral cavity and below the tongue. They produce saliva, which moistens both food in the oral cavity and the oral cavity itself, and contains the enzyme amylase, which breaks the food into maltose.
What occurs during the procedure of swallowing?
- the features of the mouth allow swallowing and breathing, but not at the same time.
- as swallowing begins, the epiglottis is lowered so that food is directed down the esophagus.
- the tongue and muscles at the back of the throat contract to force food down the esophagus.
- automatic reflexes then force the food down the esophagus and into the stomach.
What are the four main types of teeth and what is their function?
Molars: there are four main groups of three molars in adults they add used as the main grinding surface in the mouth.
Premolars: four groups of two premolars In the mouth. They combine the role of canines and molars.
Canines: four canines in adults. They are primarily used for gripping food.
Incisors: eight incisors in adults. Used for biting, shearing and cutting food.
Where do the feet sit inside the mouth?
The teeth fit inside sockets in the maxilla (upper jaw) and the mandible (lower jaw) and are secured by peridontal ligament tissues attached to the root. Deciduous teeth begin to be lost at the age of 8.
What happens when Wisdom teeth grow?
They are often extracted as there is not usually enough room in the oral cavity for them. Wisdom teeth often become impacted as they move through the gum. Impacted teeth can cause chronic pain and inflammation in the gum.
What is the basic structure of the tooth when In the gum?
The portion of the tooth above the gum is termed the crown. The part embedded into the jaw is termed the root. The covered with enamel, the hardest substance in the body. Denting is a softer layer beneath the layer that makes up the bulk of a tooth. The pulp cavity contains the nerves and blood vessels.
What is the role of the digestion system?
To ingest food, digest it, absorb nutrients from the food, and eliminate undigested material.
What is the stomach?
The stomach is a muscular, J shaped enlargement of the intestinal tract. It connects the esophagus to the duodenum. It acts as a mixing area, mixing acids and digestive enzymes into food to form chyme.
What is the role of the pancreas and the gall bladder?
They both provide digestive enzymes that enter the small intestine at the duodenum.
What are the three sections of the small intestine and what is its main function?
The duodenum, the jejunum and the ileum make up the small intestine. The main function of the SI is to absorb nutrients into the blood. The SI is lined with villi, finger like projections that absorb nutrient molecules.
What is a special feature of the villi?
The villi are lined with epithelial cells and each has a brush border of many microvilli which further increase the surface area. Enzymes bound to the epithelial cells break down peptides and carbohydrate molecules.
How are the epithelial cells protected from enzymatic digestion?
The goblet cells produce a mucus to protect them.
What is the hepatic portal system and what does it have to do with the liver?
After absorption, nutrients are transported to the liver for processing via the hepatic portal system. The hepatic portal system refers to all the blood that passes through the liver before returning to the heart. The liver monitors and processes the nutrients in the blood before it passes into the general circulation.
What is the role of the large intestine?
After most of the nutrients have been absorbed in the small intestine the remaining fluid content is passed onto the LI. The
LI composes of three main sections: the cecum, the colon and the rectum. In humans the main function of the LI is to reabsorb water and electrolytes.
Where is feces stored in the LI before excretion?
The rectum.
What happens when not enough water is absorbed in the LI?
It causes diarrhoea.
What happens when too much water is absorbed in the LI?
Feces becomes hard to pass and causes constipation.
What happens In the stomach 1-2 hours after eating?
Peristaltic contractions of the stomach move the chyme towards the pylorus. Each contraction moves about 3ml of chyme through the pyloric sphincter into the duodenum.
What is peristalsis?
Circular muscle contracts behind the food and expands in front of it, producing a travelling wave.
What are the specific roles of the liver?
Production of bile, storage and procession of nutrients and detoxification of poisons and metabolic wastes.
Why are the organs of the respiratory system vital?
They are vital as they enable the gas exchange of respiratory gases essential to life.
What does the respiratory system comprise of?
The nasal cavity, the larynx, trachea and bronchi, and lungs.
How does the respiratory system interact with the digestive system?
The digestive system provides the nutrients required by the respiratory system.
What does breathing have to with the respiratory system?
Breathing provides a constant supply of fresh air to the lungs and helps maintain a perfect diffusion gradient for respiratory gases a cross the respiratory membrane. Oxygen must be breathed in to supply the respiratory needs of the body’s cells. Carbon dioxide from metabolism must be removed by breathing out.
What occurs during inspiration?
During quiet breathing (at rest) inspiration is achieved by increasing the space ( and therefor decreasing the pressure) inside the lungs. Air then flows into the lungs in response to the decreased pressure in the lungs.
