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2 Welcome back! Please write a response to the following: Imagine a time that you have been stressed, please describe the physical sensations that you felt. (you can use the movie clip you just watched if you want.) EQ: How do you keep your balance? The Endocrine System Think - Pair - Share Review Homeostasis What is a hormone? Negative Feedback How does it work? Sugar regulation

3 Hormones and Stress Phases: Alarm Resistance Exhaustion

4 Hormones and Stress

5 Hormones and Stress

6 Hormones and Stress

7 Check for Understanding When is stress good? When is it bad? What are its effects (both short and long term)?

8 Homeostasis What is homeostasis? What maintains it? Where is it maintained? What is negative feedback?

9 Homeostasis is preserved through intercellular communication

10 Hormones What are the signals? Where do they go?

11 The Endocrine System

12 The Endocrine System

13 Target Cells and Hormones

14 Regulating Blood Glucose Levels When levels rise: insulin When levels fall: glucagon

15 EXCHANGES WITH THE EXTERNAL ENVIRONMENT Every organism is an open system, continuously exchanging chemicals and energy with its surroundings to survive Pearson Education, Inc.

16 An animal s size and shape affect how it exchanges energy and materials with its surroundings. All living cells must be bathed in a watery solution so that exchange of materials can occur Pearson Education, Inc.

17 The entire surface area of an amoeba is in contact with the environment Pearson Education, Inc.

18 Exchange Mouth Gastrovascular cavity Exchange Exchange (a) Single cell (b) Two cell layers Figure 21.9

19 Exchange (a) Single cell Figure 21.9a

20 A hydra has a body wall only two cell layers thick. Both layers are bathed in pond water, enabling exchange with the environment Pearson Education, Inc.

21 Gastrovascular cavity Exchange Exchange (b) Two cell layers Figure 21.9b

22 Animals with complex body forms face the same basic problems. Every cell must: Be bathed in fluid Have access to essential nutrients from the outside environment 2010 Pearson Education, Inc.

23 Complex animals have extensively folded or branched internal surfaces that maximize surface area for exchange with the environment. Lungs: Have a very large total surface area Exchange oxygen and carbon dioxide with the air 2010 Pearson Education, Inc.

24 Figure 21.10

25 Animals use three organ systems to exchange materials with the external environment: Digestive Respiratory Urinary The circulatory system transports materials inside the body from these exchange surfaces Pearson Education, Inc.

26 Mouth Food CO 2 O 2 External environment Animal Digestive system Blood Respiratory system Heart Interstitial fluid Nutrients Circulatory system Body cells Urinary system Anus Unabsorbed matter (feces) Metabolic waste products (such as urine) Figure 21.11

27 REGULATING THE INTERNAL ENVIRONMENT Every living organism has the ability to respond to its environment Pearson Education, Inc.

28 Homeostasis Homeostasis is the body s tendency to maintain relatively steady conditions in the internal environment when the external environment changes. The internal environment of vertebrates is the interstitial fluid, which fills the spaces between cells Pearson Education, Inc.

29 External environment Homeostatic mechanisms Animal s internal environment Small internal changes Large external changes Figure 21.12

30 Negative and Positive Feedback Most mechanisms of homeostasis depend on a common principle called negative feedback, in which the results of a process inhibit that same process, such as a thermostat that turns off a heater when room temperature rises to the set point. Animation: Negative Feedback Animation: Positive Feedback 2010 Pearson Education, Inc.

31 Response: Heating stops Thermostat (control center) turns heater off Room temperature drops Stimulus: Room temperature is above set point Set point: Room temperature 20 C (68 F) Room temperature rises Stimulus: Room temperature is below set point Response: Heating starts Thermostat (control center) turns heater on Figure 21.13

32 Response: Heating stops Thermostat (control center) turns heater off Room temperature drops Stimulus: Room temperature is above set point Set point: Room temperature 20 C (68 F) Figure 21.13a

33 Set point: Room temperature 20 C (68 F) Room temperature rises Stimulus: Room temperature is below set point Response: Heating starts Thermostat (control center) turns heater on Figure 21.13b

34 Less common is positive feedback in which the results of a process intensify that same process, such as uterine contractions during childbirth Pearson Education, Inc.

35 Thermoregulation Thermoregulation is the maintenance of internal body temperature. Endotherms derive the majority of their body heat from their metabolism. Ectotherms obtain body heat primarily by absorbing it from their surroundings Pearson Education, Inc.

36 Humans have homeostatic mechanisms that aid in thermoregulation, which: Cool or Heat the body Blast Animation: Negative Feedback: Body Temperature 2010 Pearson Education, Inc.

37 Sweat gland Skin Response: 1. Blood vessels dilate 2. Sweat is produced Control center in brain activates cooling mechanisms Body temperature drops Stimulus: Body temperature is above set point Set point: Body temperature near 37 C (98.6 F) Body temperature rises Stimulus: Body temperature is below set point Skin Response: 1. Blood vessels constrict 2. Muscles shiver 3. Metabolic rate increases Control center in brain activates warming mechanisms Figure 21.14

38 Sweat gland Skin Response: 1. Blood vessels dilate 2. Sweat is produced Control center in brain activates cooling mechanisms Body temperature drops Stimulus: Body temperature is above set point Set point: Body temperature near 37 C (98.6 F) Figure 21.14a

39 Set point: Body temperature near 37 C (98.6 F) Body temperature rises Stimulus: Body temperature is below set point Skin Response: 1. Blood vessels constrict 2. Muscles shiver 3. Metabolic rate increases Control center in brain activates warming mechanisms Figure 21.14b

40 Fever: Is an abnormally high internal body temperature Usually indicates an ongoing fight against infection 2010 Pearson Education, Inc.

41 The Process of Science: How Does a Python Warm Her Eggs? Observation: A female Burmese python incubating eggs: Wraps her body around them Raises her body temperature Frequently contracts the muscles in her coils 2010 Pearson Education, Inc.

42 Hypothesis: The muscle contractions elevate the snake s body temperature. Experiment: A python and her eggs were monitored to measure: The python s muscle contractions Her oxygen uptake 2010 Pearson Education, Inc.

43 Results: The python s oxygen consumption increased: When the temperature in the chamber decreased and As she increased the rate of muscle contraction Pearson Education, Inc.

44 120 O 2 consumption (ml O 2 /hr) per kg Contractions per minute Figure 21.15

45 Osmoregulation Living cells depend on a precise balance of: Water Solutes Osmoregulation is the control of the gain or loss of: Water Dissolved solutes, such as salt 2010 Pearson Education, Inc.

46 Osmoconformers: Have internal and external environments with similar water concentrations Include most marine invertebrates Osmoregulators Actively regulate their water loss or gain Include freshwater animals, most marine vertebrates, and all land animals 2010 Pearson Education, Inc.

47 Osmocomformer Osmoregulator Figure 21.16

48 Homeostasis in the Urinary System The urinary system: Plays a central role in homeostasis Forms and excretes urine Regulates the amount of water and solutes in body fluids 2010 Pearson Education, Inc.

49 In humans, the two kidneys: Are the main processing centers Contain many fine tubes called tubules Include an intricate network of capillaries 2010 Pearson Education, Inc.

50 As blood circulates through the kidneys: A fraction of it is filtered Plasma enters the kidney tubules, forming filtrate Filtrate contains: Valuable substances that need to be reclaimed (such as water and glucose) Substances to be eliminated, such as urea 2010 Pearson Education, Inc.

51 The human urinary system includes: The circulatory system The kidneys Nephrons, the functional units of the kidney The urinary bladder, where urine is stored Animation: Nephron Introduction 2010 Pearson Education, Inc.

52 Renal artery (red) and renal vein (blue) Kidney Ureter Filter Branch of renal artery Branch of renal vein Tubule Collecting duct Urinary bladder Urethra To ureter (c) A nephron and collecting duct (a) Urinary system Ureter (b) Kidney Figure 21.17

53 Renal artery (red) and renal vein (blue) Kidney Ureter Urinary bladder Urethra (a) Urinary system Figure 21.17a

54 Nephron Ureter (b) Kidney Figure 21.17b

55 Nephrons: Carry out the functions of the urinary system Consist of a tubule and its associated vessels Number more than a million in a kidney 2010 Pearson Education, Inc.

56 Filter Tubule Branch of renal artery Branch of renal vein Collecting duct To ureter (c) A nephron and collecting duct Figure 21.17c

57 Nephrons perform four key functions: Filtration, forcing water and other small molecules from the blood to form filtrate Reabsorption of water and valuable solutes back into the blood Secretion of certain substances, such as ions and drugs, into the filtrate Excretion of urine from the kidneys 2010 Pearson Education, Inc.

58 Animation: Bowman s Capsule and Proximal Tubule Animation: Collecting Duct Animation: Effect of ADH Blast Animation: How the Kidney Works Animation: Loop of Henle and Distal Tubule 2010 Pearson Education, Inc.

59 Filtration Reabsorption Secretion Renal artery Filtrate Renal vein Capillaries Tubule Excretion Urine Figure 21.18

60 Hormonal control of the nephrons allows the body to control its internal concentration of: Water Dissolved molecules 2010 Pearson Education, Inc.

61 Kidney failure can be caused by: Injury Illness Prolonged use of pain relievers, alcohol, or other drugs One option for treatment of kidney failure is dialysis, filtration of blood by a machine Pearson Education, Inc.

62 Line from artery to apparatus Pump Tubing made of a selectively permeable membrane Line from apparatus to vein Dialyzing solution Fresh dialyzing solution Used dialyzing solution (with urea and excess salts) Figure 21.19

63 Evolution Connection: Adaptations for Thermoregulation Animals regulate their body temperatures using adaptations that are: Anatomical Physiological, and / or Behavioral 2010 Pearson Education, Inc.

64 METHODS OF THERMOREGULATION Anatomical Adaptations Physiological Adaptations Behavioral Adaptations Fat Hair Panting Bathing Figure 21.20

65 Anatomical Adaptations (such as hair, fat, and feathers) Fat Hair Figure 21.20a

66 Physiological Adaptations (such as panting, shivering, and sweating) Panting Figure 21.20b

67 Behavioral Adaptations (such as bathing, basking, hibernating, and migrating) Bathing Figure 21.20c

68 HIERARCHICAL ORGANIZATION OF ANIMALS Level Cell Description The basic unit of all living organisms Example Muscle cell Tissue A collection of similar cells that perform a specific function Cardiac muscle Organ Multiple tissues forming a structure that performs a specific function Heart Organ system A team of organs that work together Organism A living being, which depends on the coordination of all structural levels for homeostasis and survival Circulatory system Person Figure 21.UN01

69 HIERARCHICAL ORGANIZATION OF ANIMALS Level Description Example Cell The basic unit of all living organisms Muscle cell Figure 21.UN01a

70 HIERARCHICAL ORGANIZATION OF ANIMALS Level Description Example Tissue A collection of similar cells that perform a specific function Cardiac muscle Figure 21.UN01b

71 HIERARCHICAL ORGANIZATION OF ANIMALS Level Description Example Organ Multiple tissues forming a structure that performs a specific function Heart Figure 21.UN01c

72 HIERARCHICAL ORGANIZATION OF ANIMALS Level Description Example Organ system A team of organs that work together Circulatory system Figure 21.UN01d

73 HIERARCHICAL ORGANIZATION OF ANIMALS Level Description Example Organism A living being, which depends on the coordination of all structural levels for homeostasis and survival Person Figure 21.UN01e

74 Muscle (contracts) Connective (supports organs) Epithelial (covers body surfaces and organs) Nervous (relays and integrates Information) Figure 21.UN02

75 External Internal Homeostasis Large changes Small changes within an acceptable range Figure 21.UN03

76 Blood Capillary Filtration Water and small molecules enter the tubule. Tubule Reabsorption Water and valuable solutes are returned to the blood. Secretion Specific substances are removed from the blood. Urine Excretion Urine exits the body. Figure 21.UN04

77 The Endocrine System in Perspective Functional Relationships Between the Endocrine System and Other Systems Copyright 2010 Pearson Education, Inc.

78 The Integumentary System The Integumentary System protects superficial endocrine organs; epidermis synthesizes vitamin D 3 Copyright 2010 Pearson Education, Inc. The Endocrine System s sex hormones stimulate sebaceous glands, influence hair growth, fat distribution, and apocrine sweat glands; PRL stimulates development of mammary glands; suprarenal hormones alter dermal blood flow, stimulate release of lipids from adipocytes; MSH stimulates melanocytes

79 The Skeletal System The Skeletal System protects endocrine organs, especially in the brain, chest, and pelvic cavity The Endocrine System regulates skeletal growth: PTH and calcitonin mobilize calcium; sex hormones speed growth and close epiphyseal cartilages at puberty, and help maintain bone mass in adults Copyright 2010 Pearson Education, Inc.

80 The Muscular System The Muscular System provides protection for some endocrine organs The Endocrine System adjusts Muscle metabolism, energy production, and growth; regulates calcium and phosphate levels in body fluids; speeds skeletal muscle growth Copyright 2010 Pearson Education, Inc.

81 The Nervous System The Nervous System s hormones control secretions by the pituitary, other endocrine organs, and suprarenal medullae; secretes ADH and oxytocin The Endocrine System s hormones affect neural metabolism; help regulate fluid and electrolyte balance; reproductive hormones influence CNS development and behaviors Copyright 2010 Pearson Education, Inc.

82 The Cardiovascular System The Cardiovascular System s Vessels distribute hormones throughout the body; heart secretes ANP The Endocrine System s hormone EPO regulates production of RBCs; several hormones elevate blood pressure; Epinephrine elevates heart rate and contraction force Copyright 2010 Pearson Education, Inc.

83 The Lymphoid System The Lymphoid System s lymphocytes defend against infection and, with other WBCs, assist in repair after Injury The Endocrine System s hormones have anti-inflammatory effects (glucocorticoids), stimulate development of lymphocytes (thymosins), and affect immune function Copyright 2010 Pearson Education, Inc.

84 The Respiratory System The Respiratory System provides oxygen and eliminates carbon Dioxide generated by endocrine Cells The Endocrine System s hormones Epinephrine and NE stimulate respiration and dilate respiratory passageways Copyright 2010 Pearson Education, Inc.

85 The Digestive System The Digestive System provides nutrients to endocrine cells; Pancreas secretes insulin and glucagon; liver produces angiotensinogen The Endocrine System s hormones Epinephrine and NE constrict sphincters and depress activity along digestive tract; digestive tract hormones coordinate secretions along tract Copyright 2010 Pearson Education, Inc.

86 The Urinary System The Urinary System s kidney cells (1) release renin and EPO when local blood pressure declines and (2) produce calcitriol The Endocrine System s hormones (aldosterone, ADH, and ANP) adjust fluid and electrolyte reabsorption in kidneys Copyright 2010 Pearson Education, Inc.

87 The Reproductive System The Reproductive System s steroid sex hormones and inhibin suppress secretion in hypothalamus and pituitary The Endocrine System s hypothalamic and pituitary hormones regulate sexual development and function; oxytocin stimulates contractions of the uterus and mammary glands Copyright 2010 Pearson Education, Inc.