Chapter 16 Tissues Organs and Organ Systems Organ

Chapter 16 Tissues, Organs, and Organ Systems Organ Donation Copyright © 2010 Pearson Education, Inc.

Chapter 16 Section 1 Tissues Copyright © 2010 Pearson Education, Inc.

16. 1 Tissues Levels of organization: § § § Cells Tissues Organ Systems Organisms Smallest Largest Tissues = group of similar cell types that perform a common function. Copyright © 2010 Pearson Education, Inc.

16. 1 Tissues = group of similar cell types that perform a common function. Four basic types of tissue: 1. 2. 3. 4. Epithelial Connective Muscle Nervous Copyright © 2010 Pearson Education, Inc.

16. 1 Tissues - Epithelial Tissue Epithelium is tightly packed sheets of cells § cover organs and outer surfaces § line insides of hollow organs, vessels, and body cavities. Copyright © 2010 Pearson Education, Inc. (a) Examples of organs lined with epithelial (b) Epithelial cells in skin tissue: Heart and blood vessels Epidermis Respiratory tract Digestive tract Urogenital tract (c) Epithelial cells lining the small intestine Figure 16. 1

16. 1 Tissues - Epithelial Tissue Epithelia are polar § anchored on one surface, but free on another § The free side is typically exposed to the environment or body fluids § Can be single layer or many layers thick § Function in protection, secretion, and absorption § Epithelial cells are continuously sloughing off and are replaced by cell division Copyright © 2010 Pearson Education, Inc.

16. 1 Tissues - Connective Tissue § Loosely organized and composed of cells embedded in a matrix § Cells § Examples include: Blood cells, adipocytes, fibroblasts, chondrocytes, osteocytes § Matrix is composed of two things 1. Ground substance § May be liquid, gel-like, rubbery or solid 2. Fibers § Collagen, elastin, reticular fibers Copyright © 2010 Pearson Education, Inc.

16. 1 Tissues - Connective Tissue § Usually binds organs or tissues to one another § Six different types: 1. 2. 3. 4. 5. 6. Loose connective tissue Adipose tissue Blood Fibrous connective tissue Cartilage Bone Copyright © 2010 Pearson Education, Inc.

16. 1 Tissues - Connective Tissue Loose Connective Tissue § Most widespread tissue in animal body § Matrix composed of collagen and elastin fibers § Cells are fibroblasts and adipocytes § It is called “loose” because fibers are loosely woven together § Binds epithelia to tissues, pads skin, and holds organs in place Copyright © 2010 Pearson Education, Inc. Figure 16. 2 a

16. 1 Tissues - Connective Tissue Adipose Tissue § AKA Fat § Primarily adipocytes; small amount of matrix § Functions § Used for storage of energy (fat) § Insulation § Padding for organs Copyright © 2010 Pearson Education, Inc. Figure 16. 2 b

16. 1 Tissues - Connective Tissue Blood § Cellular component § red blood cells, white blood cells and platelets § Matrix is the plasma § Functions include carrying oxygen and nutrients; fighting infection Copyright © 2010 Pearson Education, Inc. (c) Blood Platelet Red blood cell Plasma White blood cell Figure 16. 2 c

16. 1 Tissues - Connective Tissue Fibrous Connective Tissue § Forms tendons and ligaments § Matrix is collagen fibers running in parallel § Cells are fibroblasts Copyright © 2010 Pearson Education, Inc. (d) Fibrous connective tissue (tendon) Fibroblast cell Parallel collagen fibers Figure 16. 2 d

16. 1 Tissues - Connective Tissue Cartilage § Cells are chondrocytes § Cells secrete rubbery matrix, collagen and elastin § Cartilage cushions joints, forms support for ears and nose § Not vascularized, so takes a long time to heal if (e) Cartilage (at the end of a bone) Chondrocytes Matrix injured Copyright © 2010 Pearson Education, Inc. Figure 16. 2 e

16. 1 Tissues - Connective Tissue Bone § Rigid connective tissue § Cells are osteocytes § Cells secrete matrix of collagen fibers and calcium salts § Bone marrow produces blood cells § Body can make use of calcium from bones if dietary levels are too low Copyright © 2010 Pearson Education, Inc. (f) Bone Central canal Matrix Osteocytes Figure 16. 2 f

16. 1 Tissues - Muscle Tissue Muscle is contractile tissue § Long, thin cylindrical cells called muscle fibers § Two proteins – actin and myosin – interact to cause contraction of muscle fibers Three types of muscle: 1. Skeletal 2. Cardiac 3. Smooth Copyright © 2010 Pearson Education, Inc.

16. 1 Tissues - Muscle Tissue Skeletal Muscle § § Usually attached to bone Produces all voluntary movements Striated – due to overlap of actin & myosin Long, thin, cylindrical shape (a) Skeletal muscle (biceps) Muscle fiber Nucleus Copyright © 2010 Pearson Education, Inc. Figure 16. 3 a

16. 1 Tissues - Muscle Tissue Cardiac Muscle § Only found in heart tissue § Striated § Involuntary, undergoes rhythmic contractions to produce heartbeat § Branched, interlocking cells propagate signal to contract almost simultaneously (b) Cardiac muscle (heart) Muscle fiber Copyright © 2010 Pearson Education, Inc. Nucleus Figure 16. 3 b

16. 1 Tissues - Muscle Tissue Smooth Muscle § Not striated § Spindle-shaped cells § Musculature of organs, blood vessels, digestive tract § Involuntary § Contracts more slowly and for longer than skeletal muscle (c) Smooth muscle (intestine) Muscle fiber Copyright © 2010 Pearson Education, Inc. Nucleus Figure 16. 3 c

16. 1 Tissues - Nervous Tissue § Neurons conduct electrical signals § Primary cells of the brain and spinal cord § Main function of neurons is to: § Sense stimuli § Process stimuli § Transmit signals § Most cells of nervous system do not undergo cell division Copyright © 2010 Pearson Education, Inc.

16. 1 Tissues - Tissue Donation Brain death and Tissue Donation § Injuries from motor vehicle accidents, burst blood vessels, and drowning are common causes of brain death § Once dead, brain cells cannot recover § Other tissues can be harvested to help others § > One person’s tissues can improve the lives of as many as 50 people. Copyright © 2010 Pearson Education, Inc.

End Chapter 16 Section 1 Tissues Copyright © 2010 Pearson Education, Inc.

Chapter 16 Section 2 Part 1 Organs and Organ Systems Copyright © 2010 Pearson Education, Inc.

16. 2 Organs and Organ Systems § Organs are composed of two or more tissue types § Organs that act together form an organ system § All the organ systems of a body form an organism Copyright © 2010 Pearson Education, Inc. Muscle cell Muscle tissue Heart organ Circulatory system Organism Figure 16. 5

16. 2 Organs and Organ Systems 12 Organ Systems Copyright © 2010 Pearson Education, Inc. Figure 16. 8

16. 2 Organs and Organ Systems – The Liver as a Model Organ § The liver sits below the diaphragm § comprised of four lobes § associated with the gall bladder. Copyright © 2010 Pearson Education, Inc. Figure 16. 6

16. 2 Organs and Organ Systems The Liver as a Model Organ § The liver is an important component of the circulatory and the digestive system. § As part of the circulatory system, the liver: § Synthesizes blood clotting factors § Removes and breaks down toxins § Regulates blood volume § Destroys old red blood cells § As part of the digestive system, the liver: § Metabolizes and stores nutrients § Produces bile Copyright © 2010 Pearson Education, Inc.

16. 2 Organs and Organ Systems Liver Structure § Epithelia § Hepatocytes § Lining blood vessels § Lining bile ducts § Connective Tissue § Loose connective tissue § Kupffer cells Copyright © 2010 Pearson Education, Inc.

16. 2 Organs and Organ Systems - The Liver as a Model Organ Liver transplants can be made from living donors or from brain dead ones § Unlike many organs, liver can regenerate itself § Portion can be taken from living donor and implanted in patient § Liver in donor and patient will regrow to normal size Copyright © 2010 Pearson Education, Inc.

End Chapter 16 Section 2 Part 1 Organs and Organ Systems Copyright © 2010 Pearson Education, Inc.

Chapter 16 Section 2 Part 2 The Digestive System Copyright © 2010 Pearson Education, Inc.

16. 2 Organs and Organ Systems The Digestive System Alimentary canal 1 Mouth • Teeth reduce the size of food, increasing surface area available for digestion by enzymes. • Enzymes in saliva then start breaking down carbohydrates. Accessory organs of the digestive system Liver • Produces bile which aids absorption of fats Gall bladder • Stores bile and empties into small intestine Pancreas • Produces digestive enzymes • Produces a buffer that neutralizes acidity of stomach acid 2 Pharynx • Epiglottis blocks the opening to the windpipe when we swallow, so that our food goes into our esophagus rather than our lungs. 3 Esophagus • The esophagus transports food to stomach by rhythmic waves of muscle contractions called peristalsis. 4 Stomach • Acidic gastric juices start breaking down foods. • The enzyme pepsin breaks down proteins. • Mucous prevents gastric juices from digesting stomach. • Pyloric sphincter regulates movement of food from stomach to small intestine. 5 Small intestine • Most digestion of carbohydrates, proteins, and fats occurs here. • Nutrients are absorbed into the bloodstream. 6 Large intestine • Water is reabsorbed. 7 Anus • Undigested materials are excreted as feces. Copyright © 2010 Pearson Education, Inc. Figure 16. 8

16. 2 Organs and Organ Systems The Digestive System Mouth • Teeth reduce the size of food, increasing surface area available for digestion by enzymes. • Amylase enzymes in saliva start breaking down carbohydrates. Copyright © 2010 Pearson Education, Inc. Figure 16. 8

16. 2 Organs and Organ Systems The Digestive System Esophagus • The esophagus transports food to stomach by rhythmic waves of muscle contractions called peristalsis. Copyright © 2010 Pearson Education, Inc. Figure 16. 8

16. 2 Organs and Organ Systems The Digestive System Stomach • HCl starts breaking down foods. • The enzyme pepsin breaks down proteins. • Mucous prevents gastric juices from digesting stomach. • Pyloric sphincter regulates movement of food from stomach to small intestine. Copyright © 2010 Pearson Education, Inc. Figure 16. 8

16. 2 Organs and Organ Systems The Digestive System Small intestine • Most digestion of carbohydrates, proteins, and fats occurs here. • Nutrients are absorbed into the bloodstream. Large intestine • Water is reabsorbed Copyright © 2010 Pearson Education, Inc. Figure 16. 8

16. 2 Organs and Organ Systems - The Digestive System Internal Specializations § Mucosal folds, villi and microvilli increase the surface area of the intestines to allow nutrient absorption Copyright © 2010 Pearson Education, Inc. Figure 16. 9

16. 2 Organs and Organ Systems The Digestive System Accessory Organs Liver • Produces bile which aids absorption of fats Gall bladder • Stores bile and empties into small intestine Copyright © 2010 Pearson Education, Inc. Figure 16. 8

16. 2 Organs and Organ Systems The Digestive System Accessory Organs Pancreas • Produces LOTS of digestive enzymes • Produces a buffer that neutralizes stomach acid • Enzymes & buffer are released into small intestine Copyright © 2010 Pearson Education, Inc. Figure 16. 8

16. 2 Organs and Organ Systems = many organs working together § Failure of one organ may compromise the organ system § Intestine transplants and pancreatic transplants are becoming more common § Gall bladder and stomach transplants are rarely done § Organ failure can also disrupt multiple systems Copyright © 2010 Pearson Education, Inc.

16. 2 Organs and Organ Systems PLAY Animation—The Digestive System Copyright © 2010 Pearson Education, Inc.

16. 2 Organs and Organ Systems Evolution of the Digestive System § Paramecia use digestive food vacuoles § Hydra have an extracellular digestive sac § Earthworms have alimentary canal § Allows for ‘assembly line’ like specialization Copyright © 2010 Pearson Education, Inc. Figure 16. 9

End Chapter 16 Section 2 Part 2 The Digestive System Copyright © 2010 Pearson Education, Inc.

Chapter 16 Section 3 Regulating the Internal Environment Organ Donation Copyright © 2010 Pearson Education, Inc.

Homeostasis § a dynamic state of equilibrium in which internal conditions remain relative stable (Steady State) § homeostasis regulates conditions in the internal environment § A homeostatic control system has § § a receptor a control center a set point an effector Copyright © 2010 Pearson Education, Inc.

LE 40 -11 Response No heat produced Heater turned off Room temperature decreases Set point Too hot Set point Control center: thermostat Too cold Room temperature increases Set point Heater turned on Response Power. Point lecture prepared by Heat James M. Hutcheon produced Georgia Southern University Copyright © 2010 Pearson Education, Inc.

16. 3 Regulating the Internal Environment Homeostasis § Negative feedback is when the outcome of a process inhibits that process. (a) If blood glucose level rises. . . Liver converts glucose to glycogen. Pancreas secretes insulin. (b) If blood glucose level falls. . . Glucose Glycogen Liver Blood glucose level falls. Homeostasis Normal blood glucose level Glucose levels rise. Glucose Glycogen Pancreas secretes glucagon. Copyright © 2010 Pearson Education, Inc. Liver breaks down glycogen into glucose and releases glucose into bloodstream. Figure 16. 11

16. 3 Regulating the Internal Environment Homeostasis § Positive feedback occurs when the outcome of a process increases or intensifies that process. § During childbirth, hormones cause muscles of uterus to contract § Uterine contractions cause even more hormones to be released, which intensify the contractions § > In animals, regulation is usually by negative feedback because positive feedback often results in amplification – away from homeostasis Copyright © 2010 Pearson Education, Inc.

16. 3 Regulating the Internal Environment – Organ Donation Copyright © 2010 Pearson Education, Inc.

16. 3 Regulating the Internal Environment – Organ Donation § The best candidates to donate organs are those who have died of brain injury. § In cardiac death, organs deteriorate due to lack of oxygen, and thus are less suitable for transplant. § Thousands of lives are saved each year through organ donation. § The decision to become a donor now can save families from making difficult decisions later. Copyright © 2010 Pearson Education, Inc.

End Chapter 16 Section 3 Regulating the Internal Environment Organ Donation Copyright © 2010 Pearson Education, Inc.

End Chapter 16 Tissues, Organs, and Organ Systems Organ Donation Copyright © 2010 Pearson Education, Inc.