Chapter 38

Front 1

calorie

Back 1

the energy needed to raise the temperature of 1 kilogram of water through 1 °C, equal to one thousand small calories and often used to measure the energy value of foods.

Front 2

carbohydrate

Back 2

any of a large group of organic compounds occurring in foods and living tissues and including sugars, starch, and cellulose. They contain hydrogen and oxygen in the same ratio as water (2:1) and typically can be broken down to release energy in the animal body.

Front 3

fat

Back 3

a natural oily or greasy substance occurring in animal bodies, especially when deposited as a layer under the skin or around certain organs. also one of the six classes of nutrients our body needs.

Front 4

protein

Back 4

any of a class of nitrogenous organic compounds that consist of large molecules composed of one or more long chains of amino acids and are an essential part of all living organisms, especially as structural components of body tissues such as muscle, hair, collagen, etc., and as enzymes and antibodies.

Front 5

vitamin

Back 5

any of a group of organic compounds that are essential for normal growth and nutrition and are required in small quantities in the diet because they cannot be synthesized by the body. For example, the B vitamins

Front 6

mineral

Back 6

a solid inorganic substance of natural occurrence. One of the six nutrients our body needs. For example, calcium or magnesium

Front 7

amylase

Back 7

an enzyme, found chiefly in saliva and pancreatic fluid, that converts starch and glycogen into simple sugars.

Front 8

esophagus

Back 8

the part of the alimentary canal that connects the throat to the stomach; the gullet. In humans and other vertebrates it is a muscular tube lined with mucous membrane.

Front 9

peristalsis

Back 9

the involuntary constriction and relaxation of the muscles of the intestine or another canal, creating wavelike movements that push the contents of the canal forward.

Front 10

stomach

Back 10

the internal organ in which the major part of the digestion of food occurs, being (in humans and many mammals) a pear-shaped enlargement of the alimentary canal linking the esophagus to the small intestine.

Front 11

chyme

Back 11

the pulpy acidic fluid that passes from the stomach to the small intestine, consisting of gastric juices and partly digested food.

Front 12

small intestine

Back 12

the part of the intestine that runs between the stomach and the large intestine; the duodenum, jejunum, and ileum collectively.

Front 13

pancreas

Back 13

a large gland behind the stomach that secretes digestive enzymes into the duodenum. Embedded in the pancreas are the islets of Langerhans, which secrete into the blood the hormones insulin and glucagon.

Front 14

liver

Back 14

a large lobed glandular organ in the abdomen of vertebrates, involved in many metabolic processes.

Front 15

villus

Back 15

any of numerous minute elongated projections set closely together on a surface, typically increasing its surface area for the absorption of substances, in particular.

Front 16

large intestine

Back 16

the cecum, colon, and rectum collectively.

Front 17

kidney

Back 17

each of a pair of organs in the abdominal cavity of mammals, birds, and reptiles, excreting urine.

Front 18

ureter

Back 18

the duct by which urine passes from the kidney to the bladder (in humans) or cloaca (in other animals).

Front 19

urinary bladder

Back 19

a hollow muscular organ that collects urine from the kidneys before disposal by urination. it sits on the pelvic floor. Urine enters it via the ureters and exits via the urethra.

Front 20

nephron

Back 20

each of the functional units in the kidney, consisting of a glomerulus and its associated tubule, through which the glomerular filtrate passes before emerging as urine.

Front 21

filtration

Back 21

process by which a liquid or gas passes through a filter to remove wastes

Front 22

glomerulus

Back 22

a cluster of capillaries around the end of a kidney tubule, where waste products are filtered from the blood.

Front 23

Bowman's capsule

Back 23

cup-shaped structure in the upper end of the nephron that encases the glomerulus

Front 24

reabsorption

Back 24

the kidney selectively reabsorbs substances it has already secreted into the renal tubules, such as glucose, protein, and sodium. These reabsorbed substances are returned to the blood.

Front 25

loop of Henle

Back 25

the part of a kidney tubule that forms a long loop in the medulla of the kidney, from which water and salts are resorbed into the blood.

Front 26

urethra

Back 26

the duct by which urine is conveyed out of the body from the bladder, and which in male vertebrates also conveys semen.