Food that is consumed must be broken down into smaller soluble particles that can be absorbed into the blood stream. This process is known as
digestion .
The digestive process consists of the following:
Ingestion – food is taken in
Digestion – food is broken down
Absorption – food particles in the bloodstream
Egestion – excretion of undigested food
Digestion may be
mechanical (chewing of teeth and peristalsis) or
chemical (enzymes).
1. What is peristalsis?
2. Which adaptation of human beings makes peristalsis possible?
3. What are enzymes?
4. Where do enzymes come from?
5. What happens to food particles after they have been absorbed into the bloodstream?
The human digestive system
Study the sketch and write down the captions and their functions:
Regions of the digestive tract
Mouth:
Teeth chew food mechanically until fine so that enzymes can operate.
Saliva from the salivary gland contains mucus to form the chewed food into a
BOLUS , as well as
AMYLASE , which digests starch. The mucus facilitates swallowing.
Throat to stomach:
The bolus is swallowed through the pharynx or throat and follows the
oesophagus or
gullet to the stomach.
PERISTALSIS propels the food, even against the force of gravity.
The
EPIGLOTTIS prevents food from slipping into the trachea (windpipe) and thus preventing choking.
Stomach:
The powerful muscles of the stomach grind the food to
CHYM within a few hours.
Enzymes and gastric juice help with the further breakdown of food particles.
The chym is passed through the
pyloric sphincter to the small intestine / ileum.
Ileum:
GALL from the liver helps with the digestion of fats by
emulsifying it.
PANCREATIC JUICE from the pancreas contains many enzymes that assist in completing digestion.
The intestinal wall is folded and has millions of small projections known as
VILLI .
The villi are responsible for the
ABSORPTION of nutrients.
Large intestine:
This is divided into a rising section, a horizontal section and a descending section.
The
COLON reabsorbs water, minerals and vitamins to conserve body fluid.
Undigested remains are stored temporarily in the last part of the large intestine, the RECTUM, until DEFECATION occurs through the ANUS.
ANSWER THE QUESTIONS THAT FOLLOW:
DIGESTIVE TRACT
1. Explain the role of the liver in the processing of toxic substances.
2. Amylose signifies starch. What is amylase?
3. What are the building blocks referred to in an earlier table?
4. What is the gastric juice referred to earlier and from where is it derived?
5. Why doesn’t acid destroy the wall of the stomach?
6. What is an ulcer? How does it develop?
7. What is a sphincter?
8. What is a spastic colon and how is it caused?
9. What is the role of roughage in the digestive process?
10. What purpose do the millions of villi in the small intestine serve?
11. Explain how the ileum is adapted to its purpose.
12. Complete the captions to clarify the structure of the villus:
Structure of a villus
Beneficial bacteria of the digestive tract
A variety of harmless bacteria are present in the alimentary canal. Some assist in the digestion of food by producing enzymes, while other bacteria produce vitamin K, which plays a role in blood clotting.
Questions & Answers
A golfer on a fairway is 70 m away from the green, which sits below the level of the fairway by 20 m. If the golfer hits the ball at an angle of 40° with an initial speed of 20 m/s, how close to the green does she come?
A mouse of mass 200 g falls 100 m down a vertical mine shaft and lands at the bottom with a speed of 8.0 m/s. During its fall, how much work is done on the mouse by air resistance
Chemistry is a branch of science that deals with the study of matter,it composition,it structure and the changes it undergoes
Adjei
please, I'm a physics student and I need help in physics
Adjanou
chemistry could also be understood like the sexual attraction/repulsion of the male and female elements. the reaction varies depending on the energy differences of each given gender. + masculine -female.
Pedro
A ball is thrown straight up.it passes a 2.0m high window 7.50 m off the ground on it path up and takes 1.30 s to go past the window.what was the ball initial velocity
2. A sled plus passenger with total mass 50 kg is pulled 20 m across the snow (0.20) at constant velocity by a force directed 25° above the horizontal. Calculate (a) the work of the applied force, (b) the work of friction, and (c) the total work.
you have been hired as an espert witness in a court case involving an automobile accident. the accident involved car A of mass 1500kg which crashed into stationary car B of mass 1100kg. the driver of car A applied his brakes 15 m before he skidded and crashed into car B. after the collision, car A s
can someone explain to me, an ignorant high school student, why the trend of the graph doesn't follow the fact that the higher frequency a sound wave is, the more power it is, hence, making me think the phons output would follow this general trend?
Nevermind i just realied that the graph is the phons output for a person with normal hearing and not just the phons output of the sound waves power, I should read the entire thing next time
Joseph
Follow up question, does anyone know where I can find a graph that accuretly depicts the actual relative "power" output of sound over its frequency instead of just humans hearing
Joseph
"Generation of electrical energy from sound energy | IEEE Conference Publication | IEEE Xplore" ***ieeexplore.ieee.org/document/7150687?reload=true
A string is 3.00 m long with a mass of 5.00 g. The string is held taut with a tension of 500.00 N applied to the string. A pulse is sent down the string. How long does it take the pulse to travel the 3.00 m of the string?
