Figure 20.0-2

2. Chapter 20: Big Ideas Figure 20.0-2 Organs and OrganSystems Structure and Functionin Animal Tissues External Exchange andInternal Regulation

3. Structure and Function in Animal Tissues

4. 20.2 Structure fits function at all levels of organization in the animal body • Anatomy is the study of structure. • Physiology is the study of function. • Animals consist of a hierarchy of levels of organization. • Tissues are an integrated group of similar cells that perform a common function. • Organs perform a specific task and consist of two or more tissues. • Organ systems consist of multiple organs that together perform a vital body function.

5. A Cellular levelMuscle cell B Tissue levelMuscle tissue Figure 20.2 C Organ levelHeart D Organ system levelCirculatory system E Organism levelMany organ systemsfunctioning together

6. 20.3 Tissues are groups of cells with a common structure and function • Tissues • are an integrated group of similar cells that perform a common function and • combine to form organs. • Animals have four main categories of tissues: • epithelial tissue, • connective tissue, • muscle tissue, and • nervous tissue.

7. 20.4 Epithelial tissue covers the body and lines its organs and cavities • Epithelial tissues, or epithelia, are sheets of closely packed cells that • cover body surfaces and • line internal organs and cavities. • Epithelial cells come in three shapes: • squamous, like a fried egg, • cuboidal, as tall as they are wide, and • columnar, taller than they are wide.

8. 20.4 Epithelial tissue covers the body and lines its organs and cavities • Epithelial tissues are named according to • the number of cell layers they have and • the shape of the cells on their apical surface.

9. Apical surface ofepithelium Basal lamina Underlying tissue Cellnuclei Figure 20.4 D Stratified squamous epithelium A Simple squamous epithelium B Simple cuboidal epithelium C Simple columnar epithelium

10. 20.5 Connective tissue binds and supports other tissues • Connective tissue can be grouped into six major types. • Loose connective tissue • is the most widespread, • consists of ropelike collagen and elastic fibers that are strong and resilient, and • helps to join skin to underlying tissues. • Fibrous connective tissue • has densely packed collagen fibers and • forms tendons that attach muscle to bone.

11. 20.5 Connective tissue binds and supports other tissues • Adipose tissue stores fat in large, closely packedcells held in a matrix of fibers. • Cartilage • is a strong and flexible skeletal material and • commonly surrounds the ends of bones.

12. 20.5 Connective tissue binds and supports other tissues Bone has a matrix of collagen fibers embedded in a hard mineral substance containing calcium, magnesium, and phosphate. Blood transports substances throughout the body.

13. White bloodcells Red bloodcell Centralcanal Plasma Matrix F Blood Figure 20.5-0 Bone-formingcells Cellnucleus E Bone Collagenfiber Cartilage-formingcells Elasticfibers A Loose connective tissue(under the skin) Matrix D Cartilage(at the end of a bone) Cell nucleus Fat droplets Collagen fibers C Adipose tissue B Fibrous connective tissue(forming a tendon)

14. 20.6 Muscle tissue functions in movement • Muscle tissue is the most abundant tissue in most animals. • There are three types of vertebrate muscle tissue: • skeletal muscle causes voluntary movements, • cardiac muscle pumps blood, and • smooth muscle moves walls of internal organs, such as the intestines.

15. Junction between two cells Unit of muscle contraction Muscle fiber(cell) Muscle fiber Nuclei Nucleus Figure 20.6-0 B Cardiac muscle A Skeletal muscle Muscle fiber Nucleus C Smooth muscle

16. 20.7 Nervous tissue forms a communication network • Nervous tissue • senses stimuli and • rapidly transmits information. • Neurons carry signals by conducting electrical impulses. • Other cells in nervous tissue • insulate axons, • nourish neurons, and • regulate the fluid around neurons.

17. Dendrites Figure 20.7 Cell body Axon

18. Organs andOrgan Systems

19. 20.8 Organs are made up of tissues • Each tissue performs specific functions. • The heart has • extensive muscle that generates contractions, • epithelial tissues that • line the heart chambers, • prevent leaks, and • form a smooth surface for blood flow, • connective tissues that make the heart elastic and strong, and • neurons that regulate contractions.

20. 20.8 Organs are made up of tissues • The small intestine • is lined by a columnar epithelium, • includes connective tissues that contain blood vessels, and • has two layers of smooth muscle that help propel food. • The inner surface of the small intestine has many finger-like projections that increase the surface area for absorption.

21. Small intestine Figure 20.8 Lumen Epithelial tissue(columnar epithelium) Connective tissue Smooth muscletissue (two layers) Connective tissue Epithelial tissue

22. 20.9 CONNECTION: Bioengineers are learning to produce organs for transplants Bioengineering is seeking ways to repair or replace damaged tissues and organs. New tissues and organs are being grown on a scaffold of connective tissue from donated organs. Other researchers are using desktop printers to create layers of different cells resembling the structure of organs.

23. Figure 20.9

24. 20.10 Organ systems work together to perform life’s functions • Each organ system typically • consists of many organs, • has one or more functions, and • works with other organ systems to create a functional organism.

25. Circulatory system Respiratorysystem Integumentary system Nasalcavity Hair Pharynx Larynx Bronchus Skin Trachea Heart Nails Lung Bloodvessels Figure 20.10-1 Skeletal system Bone Cartilage Digestivesystem Urinarysystem Muscular system Mouth Skeletal muscles Esophagus Liver Kidney Stomach Ureter Smallintestine Urinarybladder Largeintestine Urethra Anus

26. Lymphatic andimmune systems Endocrine system Hypothalamus Pituitary gland Thyroid gland Thymus Parathyroidgland Thymus Lymph nodes Adrenalgland Spleen Pancreas Appendix Figure 20.10-2 Testis(male) Ovary(female) Bonemarrow Lymphaticvessels Reproductivesystem Nervous system Brain Sense organ(ear) Seminalvesicles Female Male Spinal cord Oviduct Prostategland Nerves Ovary Vasdeferens Uterus Vagina Penis Urethra Testis

27. 20.10 Organ systems work together to perform life’s functions • The circulatory system • delivers oxygen and nutrients to body cells, • transports carbon dioxide to the lungs, and • carries metabolic wastes to the kidneys. • The respiratory system exchanges gases with the environment, • supplying the blood with oxygen and • disposing of carbon dioxide.

28. Circulatorysystem Respiratorysystem Nasalcavity Figure 20.10-3 Pharynx Larynx Bronchus Trachea Heart Lung Bloodvessels

29. 20.10 Organ systems work together to perform life’s functions • The integumentary system protects against • physical injury, • infection, • excessive heat or cold, and • drying out.

30. Integumentary system Hair Figure 20.10-4 Skin Nails

31. 20.10 Organ systems work together to perform life’s functions • The skeletal system • supports the body, • protects organs such as the brain and lungs, and • provides the framework for muscle movement.

32. Skeletal system Bone Figure 20.10-5 Cartilage

33. 20.10 Organ systems work together to perform life’s functions • The muscular system • moves the body, • maintains posture, and • produces heat.

34. Muscular system Skeletal muscles Figure 20.10-6

35. 20.10 Organ systems work together to perform life’s functions • The urinary system • removes waste products from the blood, • excretes urine, and • regulates the chemical makeup, pH, and water balance of blood. • The digestive system • ingests and digests food, • absorbs nutrients, and • eliminates undigested material.

36. Digestivesystem Urinarysystem Figure 20.10-7 Mouth Esophagus Liver Kidney Stomach Ureter Smallintestine Urinarybladder Largeintestine Urethra Anus

37. 20.10 Organ systems work together to perform life’s functions The endocrine system secretes hormones that regulate body activities.

38. Endocrine system Hypothalamus Pituitary gland Thyroid gland Thymus Parathyroidgland Figure 20.10-8 Adrenalgland Pancreas Testis(male) Ovary(female)

39. 20.10 Organ systems work together to perform life’s functions The lymphatic and immune systems protect the body from infection and cancer. The lymphatic system also returns excess body fluid to the circulatory system.

40. Lymphatic andimmune systems Thymus Lymph nodes Figure 20.10-9 Spleen Appendix Bonemarrow Lymphaticvessels

41. 20.10 Organ systems work together to perform life’s functions • The nervous system coordinates body activities by • detecting stimuli, • integrating information, and • directing responses.

42. Nervous system Brain Sense organ(ear) Figure 20.10-10 Spinal cord Nerves

43. 20.10 Organ systems work together to perform life’s functions • The reproductive system produces • gametes and • sex hormones. • The female reproductive system • supports a developing embryo and • produces milk.

44. Reproductivesystem Figure 20.10-11 Seminalvesicles Male Female Oviduct Prostategland Ovary Vasdeferens Uterus Vagina Penis Urethra Testis

45. 20.11 The integumentary system protects the body • The skin consists of two layers. • The epidermis • is a stratified squamous epithelium and • forms the surface of the skin. • The dermis • forms a deeper skin layer, • is composed of dense connective tissue with many resilient elastic fibers and strong collagen fibers, and • contains hair follicles, oil and sweat glands, muscle cells, nerves, sensory receptors, and blood vessels.

46. Hair Figure 20.11 Epidermis Sweatpore Muscle Dermis Nerve Sweat gland Hypodermis(under the skin) Adipose tissue Blood vessels Oil gland Hair follicle

47. 20.11 The integumentary system protects the body • Skin has many functions. • The epidermis • resists physical damage, • decreases water loss, and • prevents penetration by microbes. • The dermis • collects sensory information, • synthesizes vitamin D, and • helps regulate body temperature.

48. 20.11 The integumentary system protects the body • Exposure of the skin to ultraviolet light • causes skin cells to release melanin, which contributes to a visible tan, and • damages DNA of skin cells, which can lead to • premature aging of the skin, • cataracts, and • skin cancers.

49. 20.11 The integumentary system protects the body • Hair • is an important component of the integumentary system of mammals, • helps to insulate their bodies, and • consists of a shaft of keratin-filled dead cells. • Oil glands release oils that • are associated with hair follicles, • lubricate hair, • condition surrounding skin, and • inhibit the growth of bacteria.

50. 20.12 SCIENTIFIC THINKING: Well-designed studies help answer scientific questions As consumers, we are bombarded with claims daily. To make informed decisions and behave as responsible consumers, we should evaluate information as scientists do. For example, consider claims for acne treatment.