Levels of Organization and Organ Systems

Transcription

1 Levels of Organization and Organ Systems The human body is structured into. Recall that cells are the smallest units of life. Cells that are similar in and work together as. The human body has four primary kinds of tissue: Epithelial tissue Connective tissue Muscle tissue Nervous tissue Different types of tissues work together to form, which carry out particular functions. Examples include,,, and. Organs cannot do all of the necessary work to sustain the body on their own. They must work together with other organs with related functions ( ) or structures ( ). This is referred to as an. The following is a list of the body s major organ systems and their functions: Organ System Major Organs Major Function Esophagus, stomach, intestines, liver, pancreas Heart, blood vessels Lungs, trachea, blood vessels Testes, vas deferens, ovaries, uterus, fallopian tubes Kidney, bladder, ureter, urethra Bones, muscles Physical and chemical breakdown of food Transportation of nutrients, gases and waste; defence against infection Gas exchange Sexual reproduction Removal of waste Movement of body and body parts Pancreas, pituitary gland, adrenal glands Brain, spinal cord, eyes, ears, nose, tongue, nerves Coordination and chemical regulation of body activities Response to environment; control of body activities

2 What is Nutrition? Nutritional science is the study of and found in foods that affect human and. A thorough understanding about nutrition enables people to make. A nutrient is an that is broken down by the body. Good nutrition is important because it: a) Provides the we need to carry out all of our. b) Provides us with the essential that we need as building blocks. There are three main categories of nutrients: 1. MACRONUTRIENTS (Macromolecules) Macromolecules are required by the body in amounts. These molecules form the and carry out the of all cells. They are molecules that may contain anywhere from to of carbon atoms. Because of their and the intricate that macromolecules can assume, these large molecules are capable of performing a wide variety of complex with great and. Macromolecules are of smaller units ( ) linked together. There are four classes of macromolecules in cells: i. CARBOHYDRATES (polymers of ) ii. LIPIDS (polymers of ) iii. PROTEINS (polymers of ) iv. NUCLEIC ACIDS (polymers of ) Monomers are linked together by bonds. are responsible for the and of macromolecules. 2. MICRONUTRIENTS Micronutrients are needed by the body amounts. There are two main classes of micronutrients: i. Mineral - an substance (such as copper, iron, calcium or phosphorous) that is needed in all body structures in amounts for various

3 functions, such as the transmission of and contractions;, therefore must be supplied by or ii. Vitamin an molecule that acts as a for essential in the body, such as converting fats and carbohydrates into energy; can be or ;, therefore must be supplied by or 3. Special Nutrient Water is the considered a special nutrient and is required by all living things. Water is the most abundant molecule in any cell (constitutes of the human body). It functions to act as a carrier for inside ( ) and outside ( ) of the cell, and as a medium for ( ). It also functions as a between organs, tissues and individual cells. The following properties of water make life possible, as we know it: a) Remains over wide range of temp (1 C - 99 C) b) most substances involved in living processes such as,,, and c) Changes temperature gradually ( ) when heated or cooled so it protects cells from rapid temperature changes and therefore a stable environment A balanced diet should provide all essential vitamins and minerals. Supplements maybe required for those who are ill, planning to have children, recovering from injury, suffering from digestive problems or choose not to eat an optimal diet. Canada s Food guide recommends the following daily servings for a balanced diet: Food Group Grain Vegetables and Fruit Daily Servings Milk Products or Substitutes Meat and Alternatives

4 Nutritional information about the food you are eating is found on most packaging: a) Specific amount of food All the information in the Nutrition Facts table is based on a specific amount of food. The specific amount may be indicated by a phrase such as: a slice, one egg, two cookies, followed by the metric measure (grams, cups, millilitre etc ) b) % Daily Value The % Daily Value provides a quick overview of the nutrient profile of the food, allowing product comparisons based on more than one nutrient. It puts nutrients on the same scale (0% - 100% Daily Value). You can quickly identify the strengths and weaknesses of a food product. c) Calories Calories are an expression about the amount of a food provides. One calorie is measured by the amount of energy it takes to raise of water by. Foods that provide energy and no other nutrients are called. d) Nutrient claims The Government has rules in place that must be met before a nutrition claim can be made on a label. Examples of nutritional claims include: Functional foods - those that provide more for your body than just essential nutrients. These benefits include strengthening the immune system, slowing the ageing process, aid digestion ( ) Whole foods - contain a natural level of a functional component ( ) Fortified foods - contain added ingredients ( )

5 Enhanced foods - contain a functional component that has been introduced into the organism from which the food comes through breeding, feeding or genetic engineering ( ) e) List of ingredients The list of ingredients is mandatory and has been on the food product package for many years. All of the ingredients for a food are listed in descending order by. The ingredients present in the greatest amount in a product are listed first. The list is also a source of information for people who want to avoid certain ingredients or verify the presence of an ingredient in a food.

6 Macromolecules Carbohydrates A green plants ability to get energy from the Sun and turn CO 2 from the air into (carbohydrates) is called and is represented by the chemical equation below: Therefore, all carbohydrates come from green plants. Carbohydrates are nutrients based on molecules of sugar; because of this they are called which means. All carbohydrates have the general formula C-H 2 O, in other words they are carbon-hydrates. The function of carbohydrates are to act as the in cells as they pass through the process of, which is represented by the chemical equation below: In photosynthesis is used to produce molecules (glucose). In cellular respiration the molecule (glucose) is broken down and releases (in the form of ATP) for the cell to use. Two important organelles are specialized for energy conversion. 1. (sites for cellular respiration) 2. (sites for photosynthesis) After plants produce glucose they can convert it into a variety of other sugar molecules by altering their shape or by bonding them together. The two main varieties of carbohydrates that we consume are such as (glucose and fructose) or (sucrose and lactose), and polysaccharides or ( of sugar in ). Simple sugars tend to provided energy supplies whereas complex carbs a more source of energy.

7 Fibre is a carbohydrate ( ) found in the of plants, that cannot be by humans. It helps to hold and provide in the large intestine, thus it helps to eliminate our waste. Current North American guidelines recommend that carbohydrates, especially carbohydrates provide to of your daily energy requirements, which should be approximately. Healthy carbohydrates such as those provided from, and are excellent dietary sources of carbohydrates. When your diet is rich in these carbohydrates, your body extracts energy from them, saving for muscle building and body repair. Whole grains are those that include all portions of the grain. Processed grains have had the and the portion removed. These areas provide a number of essential and along with some healthy and. Carbohydrates are processed to alter their and to extend their. Unhealthy sources of carbohydrates include white bread and pasta, candy, pasteries, soda and any other highly processed or refined foods. These carbs may contribute to weight gain, interfere with weight loss and promote diabetes and heart disease. is a carbohydrate that acts as a storehouse for in humans and. It is produced in the. Excess consumption of carbohydrates can get converted into (a energy molecule) and may lead to an increase in production. disease in an autoimmune response to, a collection of proteins found in grain products.

8 Lipids Fats serve as a along with providing, acting as and the main component of. Current guidelines recommend that dietary fats should supply no more than of your daily energy requirements. There are two main types of fat we consume, and. Triglycerides are composed of a molecule attached to chains. The fatty acid chains determines the type of triglyceride. The and can vary from one fatty acid to another. A) Saturated Fatty Acids There are only single bonds between each carbon atom. This organization allows for a arrangement of the fatty acid tails, allowing them to close together, which explains why saturated fatty acids are at room temperature. These are found in foods such as,, and. In the past, saturated fats have been closely associated with. More recent evidence suggests that there are other factors to consider when looking at the impact of saturated fats. As a guide, saturated fats should NOT be considered a healthy fat, but if less than of your daily calorie requirements is in the form of saturated fat it will have little impact on risk of cardiovascular disease. B) Unsaturated Fatty Acids There is one ( ) or more ( ) bonds in the carbon chain. This means that not every carbon is bonded to its maximum number of hydrogen atoms. Double bonds produce in the fatty acid chain, consequently,

9 the more double bonds the chain possess, the greater the difficulty for these chains to pack together. This explains why unsaturated fats form at room temperature ( ). These are found in foods such as olive, corn, sunflower etc or. Most naturally occurring unsaturated fatty acids are found in what is called the - configuration. These types of fats appear to total cholesterol levels. Unsaturated fats can have their double bonds chemically with hydrogen atoms (a process termed ). During this process fats are produced. The resulting molecule creates chains, which are capable of being at room temperature, such as. Trans-fats elevate (bad) cholesterol levels and lowers (good) cholesterol levels. Omega- and omega- fatty acids are essential fats found mainly in. Omega fats are required to build, the protective covering around of our cells. There are two types of cholesterol; about of cholesterol is made by our, while the other comes from : 1. Dietary Cholesterol Found in foods containing animal fat - Doesn t normally cause blood cholesterol to in most people

10 2. Blood Cholesterol Most of this cholesterol is produced by the from the triglycerides consumed Two types - HDL and LDL HDL (good) - High-Density Lipoprotein Helps from body To boost HDL -, be and maintain LDL (bad) - Low-Density Lipoprotein Clogs arteries because these are deposited on artery walls ( ), blocks circulation, increases risk or To lower LDL - cut down on and fats, eat more foods containing soluble Proteins Accounts for of the dry weight of cells Wide variety of in organisms etc Huge variety of, etc Each protein has a unique Always assembled from a common cellular pool of of the 20 amino acids are considered amino acids as they cannot be produced by the body, but must be obtained through Proteins should make-up of daily energy requirements (more if doing weight training) Animals sources such as and are sources of proteins (provide all 8 of the essential amino acids) and are proteins, because they do not provide all the essential amino acids Vegetarians attempt to avoid all meat products, although may consume dairy and egg products. Vegans will restrict their diet to foods derived from plants Vegetarians and vegans must carefully balance their food intake in order to obtain all eight essential amino acids

11 An amino acid is composed of a atom (called the carbon) bonded to four different groups: Amine group (NH 2 ) Carboxyl group Hydrogen atom Side chain shown as R-group (different for all 20 amino acids)

12 Types of Digestion All organisms must have some way of obtaining essential needed to make their own structures and to perform life functions. Organisms that depend on organic molecules manufactured by other living things are called. Digestion can occur or. External digestion is thought to be the first type of system to evolve and organisms such as and still rely on it today. In this process, enzymes are into the environment surrounding the organism, where they break down organic material and then some of the products (move from an area of concentration to concentration) back to the organism. Internal digestion evolved later, where animals make use of a system to digests organic material of their body. This method is more efficient as it allows organisms to and their food and and the environments more effectively for the digestive process. Digestion can also be considered as or. Intracellular digestion is the type of digestion in which food particles are taken and subjected to the action of enzymes there. Extracellular digestion is the digestion of food occurring (as in the tube arrangement common in animals). Types of Digestive Systems There are three main types of digestive systems: All of these systems follow the same four steps:

13 Ingestion Physical and Chemical Breakdown Absorption Egestion 1. Vacuole System Food is digested inside a vacuole formed within the cell. Examples: and 2. Closed Tube System This type of digestive system consists of a structure with only. Both ingestion and excretion occur through the same opening. In the digestive cavity, food is partially broken down by enzyme action and absorbed into cells lining the inside of the "bag". These cells complete the digestion process. Example: and a 3. Open Tube System This type of digestive system consists of a tube with openings. One opening is used to ingest food particles and the other is used to excrete waste. Examples: and. Open tube systems usually require: 1. 2.

14 Ingestion Digestion is a complex process, which results in food being broken down into its component molecules. It involves: 1) Mechanical (Physical) Digestion 2) Chemical Digestion In humans, the digestion process takes about hours and requires passage through an extremely long tube system ( ), separated into distinct regions that perform specific functions. Section Length

15 The Mouth and Pharynx Both physical breakdown and chemical digestion occur in the mouth. The and are important for digestion and the for digestion. Inside of your mouth, covering the surface of your tongue are tiny projections called, and every one holds hundreds of. Taste is closely linked to (smell); much of what we call the taste of food is actually the. Taste is a combination of sensations,, and. One theory is that taste buds for the different sensations are clustered in specific regions on the surface of the tongue. Can you figure out where these clusters are located? Sweet Sour Salty Bitter Human teeth Type of Tooth Number Function Incisor Canine Premolars Molars Wisdom Each tooth has two divisions, the and an. Enamel, which is formed of compounds, is the substance in the body.

16 A) How Chewing Helps Digestion? Sugar Appearance Before Appearance After Loose Cube B) How did the surface area of the types of sugar compare? C) How does surface area affect the rate of dissolving? Chemical digestion begins as food is chewed, and it begins to mix with produced by the three salivary glands, and. Some functions of saliva include: It wets and so food can be swallowed easier and begins the process (required for and ) It causes the food particles to stick together to form a food mass, or It contains a digestive enzyme called (or ), which breaks down starch into simple carbohydrates The tongue pushes the food to the back of the throat, and against the, which initiates the automatic reflex. The prevents and from entering the during swallowing, while the stops food from entering the cavity.

17 The Esophagus No digestion, neither nor occurs in the esophagus. It secretes, a lubricant which aids the bolus of food in its journey to the stomach. The movement of food down the digestive tube is aided by. Peristalsis consists of alternate waves of and in the muscular walls of the alimentary canal. Where the esophagus opens into the stomach, there is a ring of muscle called a. The acts as a valve and controls the passage of food from the into the. or acid indigestion occurs when backs up into the esophagus, its lining. Pain is felt in the region of the where the esophagus is located, but the condition has nothing to do with the heart. The movement of food out of the stomach, up the esophagus and out the mouth is called.

18 The Stomach and Intestines Through the digestive process, macromolecules are broken down into molecules small enough to be from the intestine and transported to cells: Carbohydrates Proteins Lipids (triglycerides) is the main process in which food is chemically broken down. During hydrolysis, a water molecule is added at the point where a occurs between. Hydrolysis occurs at a very slow rate, but is immediately sped-up by (biological catalysts made of ). Enzymes are formed by cells, which can exist, in or in. A gland is a structure made up of a complex system of tubules connected to other areas by. Enzymes are very and will only catalyze specific. Many enzymes require the presence of or in order to function properly. The Stomach The stomach is the site for temporarily storage of and initial digestion. Both breakdown and digestion occurs here. Physically the stomach has a appearance and can hold up to of food. The stomach has or that allow it to expand and contract. When your stomach is, your produces a hormone called that travels to your brain to tell you that you are hungry. When your stomach is full ( ) the hormone is produced by (fat) tissue to signal your brain that you are full. Food in the stomach is broken down mechanically into smaller particles by the of the stomach walls ( muscles). This is referred to as. The food mass is broken down chemically as it is churned and mixed with juice secreted by two types of glands: 1. Pyloric glands Secrete, which covers the stomach lining and it.

19 2. Gastric glands Secrete very gastric juice, which has a ph of to. Gastric juice contains hydrochloric acid ( ) and the digestive enzyme. When pepsinogen is converted to its active form of, the breakdown of into their individual begins. HCl helps the breakdown of macromolecules. There are three mechanisms involved in stimulating the flow of gastric juice: 1. The, or of food stimulates the to send messages via nerve impulses to the. 2. Food the of the stomach. 3. Secretion of the hormone caused by of the. Gastrin stimulates production of large amounts of. In a typical day litres of fluid pass through the lumen of an adult s gastrointestinal tract. Only about litres of that volume enters through the. The remaining litres come from body secreted along with and. A common disorder associated with the stomach occurs following the destruction of the cells in the stomach. This leads to a. Until recently, diet and stress were always thought to be the leading cause of ulcer formation. Scientists have now discovered a remarkable organism,, which thrive in the stomach s formidable environment and are believed to cause most cases of ulcers. The Small Intestine Most and almost of nutrients occur here. After food leaves the stomach, regulated by the, it enters the first part of the small intestine called the. At this stage, the partially digested food is called. The presence of chyme in the small intestine, stimulates secretion of the hormone and. When these hormones reach the pancreas and liver they stimulate the production of and. The small intestine itself produces a number of enzymes that continue the chemical digestion process, such as: Secretes which completes the breakdown of ( ) Secretes which complete the breakdown of Secretes which breaks down

20 The Pancreas Produces which stomach acid Secretes the digestive enzymes ( ), ( ) and ( ) Produces and in response to Insulin makes more to and to blood sugar levels Glucagon blood sugar levels by stimulating the breakdown of in the Insufficient insulin production can lead to The Liver Produces an agent needed for the physical digestion of Bile is stored in the Storage of ( ) Production and storage of (A, D, E and K) Process triglycerides, cholesterol many harmful substances ( ) Excessive damage to liver tissue can lead to the development of ; a condition called Peristaltic contraction continue throughout the intestines which has 3 main effects: 1. They chyme through the intestine moving the bolus along 2. They the chyme with digestive enzymes and break down food particles mechanically 3. Bring the intestinal contents into contact with the intestinal wall speeding During absorption, digested nutrients pass through and enter or in structures called.

21 The capillaries act to absorb,, etc into the system. Lacteals are part of the and absorb and into tiny vessels. The small intestine has a number of structural features that increase its surface area for maximum absorption of nutrients: 1. The small intestine is very 2. Its lining has many 3. The lining is covered with millions of called, which increase the by as much as times 4. The epithelial cells of the villi that face into the intestinal opening have tiny projections called that further increase the surface area disease is an disorder of the small intestine that occurs because of a reaction to which is found in products. Exposure to gluten causes the of the small intestine to. This interferes with the of nutrients and water causing and. disease is a chronic disease of the intestines, primarily caused by in the small and large intestines, but can affect the digestive system anywhere between the and the. The Large Intestine and materials pass from the small intestine into the large intestine. No digestion occurs in this portion of the digestive system. Functions of the large intestine include: 1. Reabsorption of from the food mass 2. Absorption of vitamins and produced by live in the large intestine 3. Elimination of undigested and indigestible material from the digestive tract ( ) Examples: from plant cell walls, large quantities of and from the digestive tract Fecal matter is stored in the last part of the large intestine, the, and periodically eliminated, or, through the.