THE HIERARCHY OF STRUCTURAL ORGANIZATION IN AN ANIMAL Copyright © 2009 Pearson Education, Inc.

 Anatomy—structure  Physiology—function  Animals consist of a hierarchy of levels or organization Copyright © 2009 Pearson Education, Inc.

Cellular level Muscle cell A

Cellular level Muscle cell Tissue level Muscle tissue A B

Cellular level Muscle cell Tissue level Muscle tissue Organ level Heart A B C

Cellular level Muscle cell Tissue level Muscle tissue Organ level Heart A B C D Organ system level Circulatory system

Cellular level Muscle cell Tissue level Muscle tissue Organ level Heart Organ system level Circulatory system Organism level Many organ systems functioning together A B C D E

Copyright © 2009 Pearson Education, Inc.  Animals have four main categories of tissues Epithelial (20.4)Connective (20.5) Muscle (20.6) Nervous (20.7) Neurons with branching extensions Long cells (fibers) with contractile proteins Sparse cells in extracellular matrix Sheets of closely packed cells Protection, exchange, secretion Binding and support of other tissues Movement of body parts Transmission of nerve signals Function Structure Tissue

 Epithelial cells come in three shapes: 1. Squamous—like a fried egg 2. Cuboidal—as tall as they are wide 3. Columnar—taller than they are wide Copyright © 2009 Pearson Education, Inc.

Apical surface of epithelium Cell nuclei Underlying tissue Basal lamina Simple squamous epithelium (air sacs of the lung) Simple cuboidal epithelium (kidney) Simple columnar epithelium (intestine) Stratified squamous epithelium (esophagus) Pseudostratified ciliated columnar epithelium (respiratory tract) A B C D E

 Connective tissue can be grouped into six major types Copyright © 2009 Pearson Education, Inc. Fat droplets Adipose tissue White blood cells Red blood cell Blood Plasma Loose connective tissue (under the skin) Elastic fibers Collagen fiber Cell Fibrous connective tissue (forming a tendon) Collagen fibers Cell nucleus Cartilage (at the end of a bone) Matrix Cartilage- forming cells Central canal Matrix Bone- forming cells Bone B A F E D C

 Skeletal muscle causes voluntary movements  Cardiac muscle pumps blood  Smooth muscle moves walls of internal organs, such as the intestines Copyright © 2009 Pearson Education, Inc. Unit of muscle contraction Muscle fiber Nucleus Muscle fiber Junction between two cells Nucleus Muscle fiber Cardiac muscle Smooth muscle Skeletal muscle C B A

 Neurons carry signals by conducting electrical impulses Copyright © 2009 Pearson Education, Inc. Cell body Nucleus

 Each tissue performs specific functions, together which make up an organ Copyright © 2009 Pearson Education, Inc. Small intestine Lumen Epithelial tissue Connective tissue Smooth muscle tissue (2 layers) Connective tissue Epithelial tissue (columnar epithelium) Lumen

 An organ system usually consists of many organs  Each organ system has one or more functions Copyright © 2009 Pearson Education, Inc.

Cartilage Bone Skeletal system Adrenal gland Pancreas Testis (male) Ovary (female) Hypothalamus Pituitary gland Thyroid gland Parathyroid gland Endocrine system B A

Circulatory system Heart Blood vessels Respiratory system Nasal cavity Larynx Trachea Bronchus Lung C D

Muscular system Integumentary system Hair Nails Skin Skeletal muscles F E

Lymphatic and immune systems G, H Thymus Bone marrow Spleen Lymph nodes Lymphatic vessels

Oviduct Ovary Female Uterus Vagina Male Seminal vesicles Prostate gland Vas deferens Penis Urethra Testis Reproductive system K

Brain Sense organ Spinal cord Nervous system Nerves L

Urinary system Esophagus Liver Stomach Small intestine Digestive system Large intestine Anus Mouth Kidney Ureter Urinary bladder Urethra J I

External environment Mouth Food Animal CO 2 O2O2 Respiratory system d Bl oo Digestive system Heart Nutrients Circulatory system Intestine Urinary system Body cells Interstitial fluid Anus Unabsorbed matter (feces) Metabolic waste products (urine)

Copyright © 2009 Pearson Education, Inc. ◦ Humpback whales strain krill from seawater using large plates, called baleen –Whales take a large gulp of water into their throat –As they force water out, it is strained through baleen plates that hang from the upper jaw ◦ Humpback whales create a net of bubbles to concentrate the krill

Copyright © 2009 Pearson Education, Inc. OBTAINING AND PROCESSING FOOD

Copyright © 2009 Pearson Education, Inc.  Most animals have one of three kinds of diets –Herbivores, plant-eaters—cattle, snails, sea urchins –Carnivores, meat-eaters—lions, hawks, spiders –Omnivores, eating both plants and other animals— humans, roaches, raccoons, crows

Mechanical digestion Pieces of food Food Chemical digestion (hydrolysis) Nutrient molecules enter body cells Small molecules Undigested material Digestion Ingestion 2 1 Absorption 3 Elimination 4 Copyright © 2009 Pearson Education, Inc.  Food is processed in four stages –Ingestion –Digestion –Absorption –Elimination

Copyright © 2009 Pearson Education, Inc.  Mechanical digestion breaks food down into smaller pieces –Smaller pieces are easier to swallow –Smaller pieces have more surface area exposed to digestive fluids

Copyright © 2009 Pearson Education, Inc. ◦ Chemical digestion breaks down large organic molecules into their components Protein- digesting enzymes Polysaccharide Macromolecule Protein Carbohydrate- digesting enzymes Components Amino acids Monosaccharides Disaccharide Nucleic acid- digesting enzymes NucleotidesNucleic acid Fat-digesting enzymes Fat Glycerol Fatty acids

Copyright © 2009 Pearson Education, Inc. ◦ Most animals have an alimentary canal with –Mouth –Anus –Specialized regions Mouth Pharynx Esophagus Crop Gizzard Anus Intestine Earthworm Dorsal fold Interior of intestine Esophagus Wall of intestine Midgut Mouth Crop Grasshopper Anus Hindgut Gastric pouches Mouth Esophagus Crop Gizzard Anus Intestine Bird Stomach

Copyright © 2009 Pearson Education, Inc. HUMAN DIGESTIVE SYSTEM

Copyright © 2009 Pearson Education, Inc. Pharynx Esophagus Oral cavity Tongue Mouth Salivary glands Gall- bladder Liver Pancreas Small intestine Rectum Anus Large intestine Esophagus Stomach Small intestine Sphincter

What happens in the oral cavity, or mouth?

Copyright © 2009 Pearson Education, Inc. Digestion begins in the oral cavity  Teeth break up food, saliva moistens it –Salivary enzymes begin the hydrolysis of starch –Buffers neutralize acids –Antibacterial agents kills some bacteria ingested with food  The tongue tastes, shapes the bolus of food, and moves it toward the pharynx  The esophagus conducts food from the pharynx to the stomach

Epiglottis up Pharynx Esophageal sphincter Bolus of food Tongue Esophagus Larynx Trachea Sphincter contracted Epiglottis down Esophagus Larynx up Sphincter relaxed Epiglottis up Sphincter contracted Larynx down

Copyright © 2009 Pearson Education, Inc.  Food is moved in waves by smooth muscle- a process called peristalsis Esophageal sphincter (contracted) Bolus of food Muscles contract, constricting passageway and pushing bolus down Stomach Bolus of food Muscles relax, allowing passageway to open

What do sphincters do?

Copyright © 2009 Pearson Education, Inc. ◦ The lower esophageal sphincter  Limits the upward movement of acids into the esophagus ◦ The pyloric sphincter –Regulates the passage of food from the stomach to the small intestine

What does the stomach do?

Copyright © 2009 Pearson Education, Inc.  Acid –pH 2 –Parietal cells secrete hydrogen and chloride ions, which combine to make ________  Pepsinogen and HCl produce pepsin –Pepsin production activates more pepsinogen production—positive feedback –Pepsin begins the chemical digestion of ________ –Acidic gastric juices mix with food to produce acid chyme

Copyright © 2009 Pearson Education, Inc. What prevents the gastric juices from digesting the walls of the stomach?

Copyright © 2009 Pearson Education, Inc.  Bacterial infections (Helicobacter pylori) in the stomach and duodenum can produce ulcers Mucous layer of stomach Bacteria

What does the small intestine do?

Copyright © 2009 Pearson Education, Inc.  Small intestine is named for its smaller diameter—it is about 6 meters long Gall- bladder Pancreatic juice Liver Bile Acid chyme Pancreas Stomach Intestinal enzymes Duodenum of small intestine

Copyright © 2009 Pearson Education, Inc.  Small intestine is named for its smaller diameter—it is about 6 meters long  Alkaline pancreatic juice neutralizes acid chyme and its enzymes digest food  Bile, made in the liver and stored in the gall bladder, emulsifies fat for attack by pancreatic enzymes The small intestine is the major organ of chemical digestion and nutrient absorption

Muscle layers Large circular folds Villi Lumen Nutrient absorption Intestinal wall Lymph vessel Blood capillaries Villi Nutrient absorption Epithelial cells Lumen of intestine Vein with blood en route to the liver Lumen of intestine Nutrient absorption into epithelial cells Microvilli Amino acids and sugars Fats Blood Fatty acids and glycerol Epithelial cells lining villus Lymph Copyright © 2009 Pearson Education, Inc. ◦ Surface area for absorption is increased by –Folds of the intestinal lining –Fingerlike villi

Copyright © 2009 Pearson Education, Inc. ◦ Nutrients pass across the epithelium and into blood ◦ Blood flows to the liver where nutrients are processed and stored Lymph vessel Blood capillaries Villi Nutrient absorption Epithelial cells Lumen of intestine Nutrient absorption into epithelial cells Microvilli Amino acids and sugars Fats Blood Fatty acids and glycerol Epithelial cells lining villus Lymph

What does the liver do?

Copyright © 2009 Pearson Education, Inc.  The liver performs many functions –Glucose is converted to glycogen and stored –Liver synthesizes many proteins including blood –Clotting proteins and lipoproteins that transport fats and cholesterol –Liver changes toxins to less toxic forms –Liver produces bile

TransmissionCausative agentChronic liver disease Vaccine Hepatitis AFecal-oralPicornaviridaeNoInactivated virus Hepatitis BParenteral, STDHepadnaviridaeYesRecombinant Hepatitis CParenteralFiloviridaeYesNo Hepatitis DParenteral, HBV coinfection DeltaviridaeYesHBV vaccine Hepatitis EFecal-oralCaliciviridaeNo Hepatitis

Large intestine??

Copyright © 2009 Pearson Education, Inc.  Diarrhea occurs when too little water is reclaimed  Constipation occurs when too much water is reclaimed  Colon bacteria produce vitamins—biotin, vitamin K, B vitamins  Feces are stored in the rectum and then eliminated

Large intestine (colon) End of small intestine Appendix Cecum Sphincter Unabsorbed food material Anus Rectum Small intestine

Copyright © 2009 Pearson Education, Inc.  The length of the digestive tract often correlates with diet  Why would a digestive tract be longer for a herbivore or omnivore than a carnivore? Small intestine Cecum Stomach Colon (large intestine) CarnivoreHerbivore

Intestine OmasumRumen Esophagus Reticulum Abomasum Rumen Small intestine Cecum Stomach Colon (large intestine) CarnivoreHerbivore

Pharynx Esophagus Oral cavity Tongue Mouth Salivary glands Gall- bladder Liver Pancreas Small intestine Rectum Anus Large intestine Esophagus Stomach Small intestine Sphincter