Co 1

Fig. 2A, B

Fig. 1.1 Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display Chemical level. Atoms (colored balls) combine to form molecules. Cell level. Molecules form organelles, such as the nucleus and mitochondria, which make up cells. Tissue level. Similar cells and surrounding materials make up tissues. Organ level. Different tissues combine to form organs, such as the urinary bladder. Organ system level. Organs, such as the urinary bladder and kidneys, make up an organ system. Organism level. Organ systems make up an organism. Wall of urinary bladder Urinary system Organism Urethra Urinary bladder Ureter Kidney Connective tissue Smooth muscle tissue Connective tissue Epithelium Smooth muscle cell Nucleus Mitochondria Smooth muscle tissue Molecule (DNA) Atoms Urinary bladder (bottom left): © Bart Harris/Corbis

Fig. 1.4 Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Body temperature (normal range) Set point Time

Fig Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. 1 1 Receptors monitor the value of a variable. In this case, receptors in the wall of a blood vessel monitor blood pressure. Receptors monitor blood pressure. Nerves

Fig Receptors monitor the value of a variable. In this case, receptors in the wall of a blood vessel monitor blood pressure. Information about the value of the variable is sent to a control center. In this case, nerves send information to the part of the brain responsible for regulating blood pressure. Receptors monitor blood pressure. Nerves Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

Fig Receptors monitor the value of a variable. In this case, receptors in the wall of a blood vessel monitor blood pressure. Information about the value of the variable is sent to a control center. In this case, nerves send information to the part of the brain responsible for regulating blood pressure. The control center compares the value of the variable against the set point. Receptors monitor blood pressure. Nerves Control center (brain) Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

Fig Receptors monitor the value of a variable. In this case, receptors in the wall of a blood vessel monitor blood pressure. Information about the value of the variable is sent to a control center. In this case, nerves send information to the part of the brain responsible for regulating blood pressure. The control center compares the value of the variable against the set point. If a response is necessary to maintain homeostasis, the control center causes an effector to respond. In this case, nerves send information to the heart. Receptors monitor blood pressure. Nerves Control center (brain) Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

Fig Receptors monitor the value of a variable. In this case, receptors in the wall of a blood vessel monitor blood pressure. Information about the value of the variable is sent to a control center. In this case, nerves send information to the part of the brain responsible for regulating blood pressure. The control center compares the value of the variable against the set point. An effector produces a response that maintains homeostasis. In this case, changing heart rate changes blood pressure. If a response is necessary to maintain homeostasis, the control center causes an effector to respond. In this case, nerves send information to the heart. Effector (heart) responds to changes in blood pressure. Receptors monitor blood pressure. Nerves Control center (brain) Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

Fig. 1.3b-2 Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Nervous System A major regulatory system that detects sensations and controls movements, physiological processes, and intellectual functions. Consists of the brain, spinal cord, nerves, and sensory receptors. Endocrine System A major regulatory system that influences metabolism, growth, reproduction, and many other functions. Consists of glands, such as the pituitary, that secrete hormones. Testes (male) Pancreas (islets) Parathyroids (posterior part of thyroid) Pineal gland Ovaries (female) Adrenals Thymus Thyroid Pituitary Hypothalamus Cauda equina Nerve Spinal cord Brain

Fig. 1.6 Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Blood pressure (normal range) The effectors respond: Heart rate increases; blood vessels constrict. Blood pressure increases: Homeostasis Restored Blood pressure decreases: Homeostasis Disturbed Blood pressure increases: Homeostasis Disturbed Blood pressure decreases: Homeostasis Restored The effectors respond: Heart rate decreases; blood vessels dilate. Start Here Blood pressure (normal range) Control centers in the brain decrease stimulation of heart and blood vessels when receptors detect increased blood pressure. Control centers in the brain increase stimulation of heart and blood vessels when receptors detect decreased blood pressure.

Fig. 1.7 Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Blood pressure (normal range) Blood flow to cardiac muscle decreases. Blood pressure decreases even more. Blood pressure decreases below normal.