Needed substances are carried to the body cells by a. enzymes. b. blood. c. water. d. food. The function of the atria is to a. pump blood to the lungs. b. pump blood to the body. c. receive blood that comes into the heart. d. deliver oxygen to body tissues. Blood vessels that carry blood away from the heart are called a. veins. b. arteries. c. capillaries. d. lymphatic vessels. When blood flows into the right atrium from the body, it contains a. little oxygen and a lot of carbon dioxide. b. a lot of oxygen and little carbon dioxide. c. a lot of both oxygen and carbon dioxide. d. little of either oxygen or carbon dioxide. In which vessels are materials exchanged between the blood and the body cells? a. veins b. arteries c. capillaries d. lymphatic vessels Which component of blood carries oxygen to the body cells? a. plasma b. platelets c. red blood cells d. white blood cells If a person’s blood lacked platelets, what process could not take place? a. carrying oxygen to cells b. carrying glucose to cells c. clotting of blood d. transfusing of blood Which chamber of the heart pumps oxygen-poor blood to the lungs? a. left atrium b. right atrium c. left ventricle d. right ventricle The function of white blood cells is to a. carry carbon dioxide. b. increase blood pressure. c. carry wastes away from body cells. d. fight disease. What substance must be present in the stomach for pepsin to work best? a. hydrochloric acid b. mucus c. saliva d. water What structure(s) enable(s) the small intestine to absorb large amounts of nutrients? a. villi b. pancreas c. liver d. gallbladder Which process takes place in the large intestine? a. Water is added to undigested food. b. Water is absorbed from undigested food. c. Digested nutrients are absorbed through the villi. d. Enzymes are added to complete chemical digestion. What organ produces bile? a. stomach b. small intestine c. pancreas d. liver _____________ is the process of the diaphragm pushing air into and out of the lungs. a. Respiration c. Peristalsis b. Breathing d. Esophagus Where does the exchange of oxygen and carbon dioxide take place in the body? a. villi c. stomach b. alveoli d. small intestine What are the products of respiration? a. oxygen and water c. carbon dioxide and water b. oxygen and carbon dioxide d. water and food During gas exchange, what substances move from the alveoli into the capillaries? a. carbon dioxide c. oxygen b. water d. nitrogen The bacteria in the ___________________ feed on the material passing through and make certain vitamins for the body. a. stomach c. large intestine b. small intestine d. rectum What is the main function of the excretory system? a. to protect the nervous system b. to strengthen skeletal muscles c. to bring oxygen to body cells d. to collect and remove wastes from the body What term do scientists use to describe the chemical process in which oxygen and glucose react to release energy inside body cells? a. inhaling b. exhaling c. breathing d. respiration What function do the kidneys perform? a. eliminate carbon dioxide b. supply oxygen to body cells c. remove urea and excess water d. play a role in gas exchange When the nervous system makes you feel hungry or thirsty, what body process is it helping to carry out? a. delivering oxygen to cells b. maintaining homeostasis c. moving the body d. supporting the body A change or signal in the environment that can make an organism react is called a(n) a. stimulus. b. reaction. c. impulse. d. response. What part of a neuron carries nerve impulses away from the cell body? a. axon b. synapse c. dendrite d. nucleus A motor neuron sends an impulse to a. a muscle or gland. b. a sensory neuron. c. an interneuron. d. another motor neuron. What part of the brain controls memory? a. cerebrum b. brainstem c. cerebellum d. spinal cord The somatic nervous system controls a. artistic ability. b. logical thinking. c. involuntary actions, such as the digestion of food. d. voluntary actions, such as turning a television on. An automatic response of the body that occurs very rapidly and without conscious control is called a(n) a. stimulant. b. interneuron. c. reflex. d. reaction. The brain and spinal cord make up the a. central nervous system. b. peripheral nervous system. c. somatic nervous system. d. autonomic nervous system. In some reflex actions, skeletal muscles contract without the involvement of a. motor neurons. b. interneurons. c. the spinal cord. d. the brain. The way the endocrine system maintains homeostasis is often compared to a(n) a. violent thunderstorm that startles people and increases their heartbeat. b. heating system that turns a furnace on and off to control a room’s temperature. c. monthly cycle that releases an egg from an ovary. d. period of human development that takes about nine months to be completed. Which of the following is an example of negative feedback in the endocrine system? a. When a hormone travels through the bloodstream, it will interact only with its target cells. b. After age 40 or so, people’s muscle strength begins to decrease and their skin starts to wrinkle. c. When people are startled by a frightening event, their heart beats faster. d. When the amount of a hormone reaches a certain level, the endocrine system stops the release of that hormone. Which of the following structures is formed when fertilization occurs? a. egg b. ovary c. sperm d. zygote Where does a fertilized egg develop after it leaves the fallopian tube? a. in the cervix b. in an ovary c. in the uterus d. in the vagina A mature egg is released from the ovary during a process called a. fallopian tube. b. ovulation. c. menstruation. d. fertilization. Which of the following describes the first nine months of human development in the correct order? a. egg, sperm, zygote b. embryo, fetus, afterbirth c. zygote, embryo, fetus d. zygote, fetus, embryo Nutrients from the mother pass to the developing embryo through a membrane called the a. vagina. b. placenta. c. cervix. d. amniotic sac. What happens during the stage of childbirth called labor? a. Strong muscle contractions push the baby out of the mother’s body. b. The fetus develops a heartbeat, its bones become distinct, and it begins to move. c. The umbilical cord is tied, then cut a few centimeters away from the baby’s abdomen. d. Strong muscle contractions of the uterus cause the cervix to enlarge. Which period makes up the stage of development called childhood? a. birth to age 7 b. birth to age 10 c. ages 7 to about 10 d. 18 months to about 12 The endocrine system acts on the body through chemical products called a. hormones b. blood and saliva c. sugars d. target cells Which endocrine gland(s) link(s) the endocrine system and the nervous system? a. hypothalamus b. parathyroid glands c. pituitary gland d. thyroid gland What leaves the mother’s body during the stage of childbirth called afterbirth? a. a baby b. the cervix c. the placenta d. the uterus Sperm are produced in the a. bladder. b. scrotum. c. testes. d. urethra. Eggs are produced in the a. ovaries. b. fallopian tubes. c. uterus. d. vagina. Human eggs are usually fertilized in the a. uterus. b. fallopian tube. c. ovary. d. cervix. The joining of a sperm and an egg is called a. implantation. b. ovulation. c. fertilization. d. menstruation. When a human egg is not fertilized, extra blood and tissue from the uterus are released through the vagina in a process called a. menstruation. b. elimination. c. ovulation. d. reproduction. The scrotum is part of the a. menstrual cycle. b. endocrine system. c. female reproductive system. d. male reproductive system.