Quiz 4 [M9 + M10]

Match the descriptions on the left with the corresponding segments of the nephron on the right. Some segments may be used more than once. Aldosterone acts on this segment. Filtration starts here. It Is U-shaped and controls osmolarity in the kidneys. ADH absorbs water in this segment. Majority of the nutrients are reabsorbed in this segment.

Aldosterone acts on this segment. --> collecting duct Filtration starts here. --> bowman's capsule It Is U-shaped and controls osmolarity in the kidneys. --> loop of Henle ADH absorbs water in this segment. --> collecting duct Majority of the nutrients are reabsorbed in this segment. --> proximal tube

Which of the following will be mainly released in response to fats in the diet? - CCK - gastrin - amylase - trypsin -insulin

CCK

Explain the term deglutition in 100-300 words.

Deglutition is more commonly known as swallowing. It is a reflex that is responsible for pushing a bolus of food or liquid into the esophagus. The reflex is stimulated when pressure is created as the tongue pushes the bolus against the soft palate and the back of the mouth. The pressure activates sensory neurons and sends a signal to the medulla oblongata. The medulla oblongata then signals motor neurons to begin the reflex. As a result, the mouth will perform the swallowing reflex and the soft pallet moves to close off the nasopharynx. Next, the skeletal muscles of the pharynx and esophagus contract to push the food forward and close off the trachea and open the esophageal sphincter. The bolus continues to move down toward the esophagus where the epiglottis folds down to prevent food from entering the airways. The bolus is propelled by peristaltic waves and aided by gravity.

Explain the differences between the structure of micelle and chylomicrons in fat absorption in 100-300 words.

Fat digestion is a complex process because fats are hydrophobic and must be emulsified prior to being digested by the small intestines. Emulsion occurs with bile salts that coat the side that will be in contact with water. Bile salts break down the coarse emulsion into smaller, more stable particles. Once the fat is broken down, it is stored in micelles that arrange themselves such that some areas are hydrophobic and others hydrophilic depending upon which side will associate with the water of the small intestines. Micelles are small disks that are made of bile salts, monoglycerides, diglycerides, and phosphilipids on the outside. On the inside, cholesterol and fatty acids are protected. As absorption occurs, monoglycerides and fatty acids enter the cell of the small intestine by diffusion and combine with triglycerides, cholesterol, and protein to form chylomicrons. Due to their size, chylomicrons must be backed into vesicles by the Golgi apparatus to exit the cell by exocytosis.

Match each function on the left with its corresponding organ on the right. It has an alkaline or basic environment. It produces chyme formation. It is thrown into folds to give a large surface area for absorption. Fats are absorbed in this part of the GIT. Protein digestion starts in this part of the GIT.

It has an alkaline or basic environment. --> intestine It produces chyme formation. --> stomach It is thrown into folds to give a large surface area for absorption. --> intestine Fats are absorbed in this part of the GIT. --> intestine Protein digestion starts in this part of the GIT. --> stomach

Match the descriptions on the left, which refer to the mammalian gastrointestinal tract, with the corresponding parts on the right. Some parts may be used more than once. - Structure where enzyme pepsin is produced. - Structure responsible for digestion of starch. - Structure where gastrin is produced. - Structure where most nutrients are absorbed. - This is where the protein-digesting enzyme trypsin is produced.

Structure where enzyme pepsin is produced. --> stomach lining Structure responsible for digestion of starch. --> salivary gland Structure where gastrin is produced. --> stomach lining Structure where most nutrients are absorbed. --> intestinal lining This is where the protein-digesting enzyme trypsin is produced. --> pancreas

Which of the following is NOT involved in the digestion of proteins? - trypsin - hydrochloric acid - pepsinogen - pepsin - lipase

lipase

The organ that detoxifies different organic compounds in the human body is the__________________.

liver

The stomach contains _______________ that requires __________________ for function.

pepsin hydrochloric acid

Which of the following substances is NOT filtered from the bloodstream through the kidneys? - water - plasma proteins - urea - glucose - sodium

plasma proteins