Question

1. which part of the small intestine is primarily involved in nutrient absorption?

a. jejunum
b. colon
c. ileum
d. duodenum

1. what is the dome - shaped muscle located beneath the lungs?

a. diaphragm
b. liver
c. trachea
d. heart

1. which organ is at the center of the circulatory system?

a. the brain
b. the lungs
c. the liver
d. the heart

1. where does the digestion process begin?

a. mouth
b. stomach
c. small intestine
d. esophagus

1. what is the primary function of the esophagus?

a. produce digestive enzymes
b. store food
c. absorb nutrients
d. transport food from mouth to stomach

1. how does the nervous system contribute to digestion?

a. produces bile
b. absorbs nutrients
c. regulates the release of digestive enzymes
d. forms feces

1. which structure prevents the trachea from collapsing?

a. diaphragm
b. bronchioles
c. alveoli
d. c - shaped rings of cartilage

Explanation:

1. The jejunum is the primary site of nutrient absorption in the small intestine.
2. The dome-shaped muscle beneath the lungs that aids breathing is the diaphragm.
3. The heart acts as the central pump of the circulatory system, moving blood throughout the body.
4. Digestion begins in the mouth with mechanical chewing and chemical breakdown via saliva.
5. The esophagus is a muscular tube that moves food from the mouth down to the stomach.
6. The nervous system sends signals to trigger the release of digestive enzymes and regulate digestive muscle contractions.
7. C-shaped rings of cartilage provide structural support to keep the trachea open.

Answer:

1. a. Jejunum
2. a. Diaphragm
3. d. The heart
4. a. Mouth
5. d. Transport food from mouth to stomach
6. c. Signals the release of digestive enzymes
7. d. C-shaped rings of cartilage