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Which of these processes occurs throughout most of the alimentary canal?

A. ingestion

B. propulsion

C. segmentation

D. absorption

Answer Explanation:

b) propulsion

- Correct: Propulsion is the movement of food along the length of the alimentary canal, from the mouth to the anus. This process occurs throughout most of the alimentary canal and includes both swallowing (deglutition) and peristalsis. Swallowing moves food from the mouth to the esophagus, while peristalsis involves rhythmic contractions and relaxations of smooth muscles in the walls of the digestive organs, pushing food forward through the esophagus, stomach, and intestines.

a) Ingestion: Ingestion refers to the intake of food into the mouth, which occurs at the beginning of the alimentary canal.

c) Segmentation: Segmentation involves the mixing and churning of food within certain regions of the digestive tract, particularly the small intestine. It does not occur throughout most of the alimentary canal but rather in specific areas where mechanical digestion and absorption are optimized.

d) Absorption: Absorption is the process by which nutrients and water are taken up from the digestive tract into the bloodstream or lymphatic system. While absorption occurs primarily in the small intestine, it also occurs in other parts of the alimentary canal, particularly in the large intestine, but it is not a continuous process throughout most of the alimentary canal like propulsion.

Therefore, the Correct Answer is B.

More Questions on TEAS 7 Science

  • Q #1: Which structure is located where the esophagus penetrates the diaphragm?

    A. esophageal hiatus

    B. cardiac orifice

    C. upper esophageal sphincter

    D. lower esophageal sphincter

    Answer Explanation

    a) esophageal hiatus

    - Correct: The structure located where the esophagus penetrates the diaphragm is called the esophageal hiatus. The esophagus passes through an opening in the diaphragm known as the esophageal hiatus as it descends from the thoracic cavity into the abdominal cavity. This hiatus allows the esophagus to connect the pharynx to the stomach.

    b) cardiac orifice

    - Incorrect: The cardiac orifice is the opening of the stomach into the esophagus. It is located at the superior portion of the stomach and is surrounded by the lower esophageal sphincter. It is not located where the esophagus penetrates the diaphragm.

    c) upper esophageal sphincter

    - Incorrect: The upper esophageal sphincter is a muscular ring located at the upper end of the esophagus, where it meets the pharynx. It controls the passage of food from the pharynx into the esophagus but is not located where the esophagus penetrates the diaphragm.

    d) lower esophageal sphincter

    - Incorrect: The lower esophageal sphincter (LES), also known as the cardiac sphincter, is a muscular ring located at the lower end of the esophagus, where it meets the stomach. It controls the passage of food from the esophagus into the stomach but is not located where the esophagus penetrates the diaphragm.

  • Q #2: Which of these ingredients in saliva is responsible for activating salivary amylase?

    A. mucus

    B. phosphate ions

    C. chloride ions

    D. urea

    Answer Explanation

    b) phosphate ions

    - Correct: Phosphate ions are responsible for activating salivary amylase. Saliva contains salivary amylase (also known as alpha-amylase or ptyalin), which is an enzyme that catalyzes the hydrolysis of starch into maltose and other smaller carbohydrates. However, salivary amylase is only activated in the presence of certain ions, particularly phosphate ions. These ions help to stabilize the enzyme's structure and facilitate its enzymatic activity. Therefore, phosphate ions play a crucial role in the function of salivary amylase.

    a) Mucus

    - Incorrect: Mucus in saliva serves primarily as a lubricant and protective barrier for the oral mucosa and facilitates swallowing. It does not directly activate salivary amylase

    c) Chloride ions

    - Incorrect: Chloride ions are electrolytes present in saliva, but they do not directly activate salivary amylase. Instead, they help maintain the osmotic balance and pH of saliva.

    d) Urea

    - Incorrect: Urea is a waste product found in urine and is not directly involved in the activation of salivary amylase.

  • Q #3: Where are most fat-digesting enzymes produced?

    A. small intestine

    B. gallbladder

    C. liver

    D. pancreas

    Answer Explanation

    d) pancreas

    - Correct: Most fat-digesting enzymes, such as pancreatic lipase, are produced in the pancreas. Pancreatic lipase is secreted by the pancreas into the small intestine, specifically the duodenum, where it plays a crucial role in the digestion of dietary fats. Additionally, other enzymes involved in fat digestion, such as pancreatic colipase and phospholipase, are also produced by the pancreas.

    a) small intestine

    - Incorrect: While some fat-digesting enzymes are present in the small intestine, the majority of these enzymes are produced by the pancreas and delivered to the small intestine via the pancreatic duct.

    b) gallbladder

    - Incorrect: The gallbladder stores and concentrates bile produced by the liver, but it does not produce fat-digesting enzymes. Bile stored in the gallbladder contains bile salts, which aid in the emulsification and digestion of fats, but they are not enzymes themselves.

    c) liver

    - Incorrect: The liver produces bile, which contains bile salts that aid in fat digestion by emulsifying large fat globules into smaller droplets, but it does not produce fat-digesting enzymes. The liver also plays a role in lipid metabolism and the synthesis of lipoproteins but does not produce enzymes directly involved in fat digestion.