The Human Body Systems The Digestive System The

The Human Body Systems The Digestive System

The Digestive System • Nutrients are important substances that enable to body to move, grow, and maintain homeostasis. • • • Proteins – growth and repair Fats – store energy Carbs – provide energy and makes cellulose Vitamins Minerals Water

Carbohydrates Made of C, H, and O. About 45 -65% of your diet should be carbs. One gram = 4 Calories Simple carbs are sugars; good for a quick burst of energy but not for stored energy. • Complex carbs, like starch and fiber, are better for long-term energy. • •

Fats • • Fat are energy-containing nutrients Made of C, O, and H One gram = 9 Calories of energy Less than 30% of your diet

Fats • Saturated fats – solid at room temp, like in meat • Unsaturated fats – liquid at room temp, like in oils • Trans fats – adding H to vegetable oils **Unsaturated can be healthy; the other two are not! • Cholesterol is a waxy, fatlike substance found in animal products; can lead to buildup of fatty material in blood vessels/heart.

Proteins • Contains C, O, H, and N. • Can be an energy source, but needed for growth and repair. • 1 gram = four Calories • 10 -35% of diet

Proteins • Made up of amino acids; your body makes about half of these on its own – the remaining amino acids must come from your food. • Meat, fish, eggs, and other animal proteins contain all of these amino acids. • Plant proteins do not contain all of these amino acids.

Vitamins • Help the body undergo chemical reactions. • Fat-soluble: they dissolve in fat and are released when needed; A, D, E, and K. • Water-soluble: dissolve in water and are not stored in the body; Vitamin C and B vitamins.

Minerals • Nutrients that are not made by living things • Only small amounts are needed • Calcium, iron, magnesium, etc.

Water • • All vital processes take place in water Helps regulate body temp and removes waste About 65% of your body You need to take in about 2 L of water every day to stay healthy.

The Digestive System • Digestion is the process of breaking down food into usable materials. • The digestive system moves food and breaks it down. • Food is moved by peristalsis: wavelike contractions of smooth muscles. – Mucous lines system to allow easy movement; muscles push material along.

Mechanical Digestion • Physical digestion – breaks food into smaller pieces. • You chew with your teeth to break food down. • The stomach also mashes food through peristalsis.

Chemical Digestion • Chemical changes take place throughout digestion. • When you chew, food particles are mixed with saliva – changes starch into sugar. – Enzyme: protein that speeds up chemical reactions in your body.

Materials move through the system. • Mouth and esophagus: • Mechanical and chemical while you chew. • The tongue pushes food to your throat, which leads into the esophagus. • It takes about 8 seconds for solids to move from through the esophagus to your stomach; only about 2 seconds for liquids.

Materials move through the system. • Stomach: • Muscles mix and mash food. • Chemical break down food – some of these are acids. • To protect your stomach, its cells replace themselves every 3 days and are covered by mucous. • Food stays here for a few hours.

Materials move through the system. Small Intestine: About 6 m long and 2 -3 cm wide Partially digested food moves here. Chemicals from pancreas, gallbladder, and liver further break down food. • Small villi are located here to absorb most of the nutrients. • • – Villi increase the surface area to increase absorption

Materials move through the system. Large Intestine: 1. 5 m long Water and some other nutrients are absorbed. Contains helpful bacteria Most of the solid material is waste, which is stored until it is ready to be expelled. • Ends with the rectum and the anus. • • •

Materials move through the system.

Other Important Organs Liver: Largest internal organ of the body Located just above stomach Filters blood and stores unneeded nutrients for later use in the body. • Produces bile – able to break down fats • Breaks down medicine and produces important proteins • •

Other Important Organs • Gallbladder: • Tiny organ connected to the liver. • Stores the bile produced by the liver. • The bile is then secreted into small intestine.

Other Important Organs • Pancreas: • Between stomach and small intestine • Produces chemicals to move food between the two organs above. – Without these, you would die of starvation. • Lowers acidity; breaks down proteins, fats, and starch.

The Human Body Systems The Circulatory System

The Circulatory System • Transports materials from the digestive and the respiratory systems to the cells. • Materials and wastes are carried in the blood – delivers oxygen and removes CO 2. • Regulates body temperature • Fights disease (blood)

The Heart • Two pumps – one on the right and one on the left, separated by a septum. • Right side – pumps to lung for oxygen; Left side – pumps to the rest of the body. • Pacemaker: group of cells in right atrium that send out signals to make the heart contract.

The Heart • Divided into chambers (atria – top, and ventricles - bottom) – separated by valves: tissue that prevents blood from flowing backward. • oxygen-poor blood goes to the right atrium; then, it is pumped to the right ventricle, and into the lungs. • Once it is oxygenated in the lungs, it flows into the left atrium and is pumped into the left ventricle.

Blood Vessels • Tube shaped structures • Arteries: take blood away from the heart and have strong walls. If walls were thin, blood pressure would burst them. • Capillaries: tiny vessels where substances are exchanged between blood and body cells. • Veins: carry blood back to the heart; thinner but wider.

Blood Vessels • Pulmonary arteries carry oxygen-poor blood to the lungs. • Pulmonary veins carry oxygen rich blood from the lungs to the heart. • Capillaries connect arteries and veins; materials are exchanged through the thin tissue.

Blood Pressure • Blood pressure refers to the force with which ventricles contract. • Healthy blood pressure allows blood to flow easily to all parts of your body. • Too low – cells don’t get enough oxygen • Too high – blood vessels are weakened and the heart has to work harder

Blood Pressure • Two systems: pulmonary system (moves blood to the lungs) and the systemic system (moves blood to the rest of the body). • Blood pressure is measured in the systemic system by a device called a sphygmomanometer. •

Blood Pressure • Measured by two numbers – one number over the other number. • The first number is the pressure in the arteries when the heart contracts; the second number is the pressure when the heart relaxes. • Normal BP: 120/80

Blood • Blood is red whether it has oxygen or not; it is brighter when there is oxygen. • Made of 4 parts: red blood cells, white blood cells, platelets, and plasma. • 60% is plasma – liquid made of proteins, glucose, hormones, and gases.

Blood • White blood cells – fight infection; larger than RBC, live for longer, but found less frequently. • Red blood cells – pick up oxygen in the lungs and bring it to the rest of the body; mostly made of hemoglobin. • Platelets are blood clotting substances; releases fibrin, which forms scabs by sticking to the injured area of the blood vessel.

Blood Types • Four blood types based on the proteins on the red blood cell’s surface. • • People with A proteins have type A blood. People with B proteins have type B blood. People with both proteins have type A-B blood. People with neither have O blood.

Blood Types • Blood transfusion – one person receives blood donated by another person. • If the wrong blood type is donated, the body attacks the unrecognized substances and the transfusion is unsuccessful.

Blood Types BLOOD TYPE CAN DONATE TO: CAN RECEIVE FROM: A A, AB A, O B B, AB B, O AB AB A, B, AB, O O

Blood • As blood moves, it loses some fluid – called lymph. • This fluid goes to lymph nodes and is then returned to the veins and arteries. • Lymphatic system – fights diseases.

The Human Body Systems The Respiratory System

Respiratory System • Functions to get oxygen from the environment and remove CO 2 from your body. • Cells need oxygen to function; oxygen is transported through the body by red blood cells. • If the oxygen and CO 2 levels are not exchanged evenly, our bodies are not in homeostasis.

The Air • About 20% oxygen • About 1% carbon dioxide • About 80% nitrogen

Cellular Respiration • Oxygen is used in a chemical reaction to release energy. • Oxygen + glucose releases energy and carbon dioxide (and water).

Structures • Air enters through nose or mouth, where cilia and mucus filter out dirt and dust particles. • The nasal cavity warms the air, and sends it down your pharynx (throat) to your trachea, or windpipe. • The epiglottis keeps air from going into your stomach.

Structures • The trachea breaks into two bronchial tubes, which branch out into several smaller tubes within the lungs. • At the end of each branch are tiny air sacs called alveoli, which controls gas exchange between oxygen and CO 2.

Structures • The rib cage encases and protects the thoracic cavity. • The diaphragm goes across the thoracic cavity; when you breathe in, this muscle pulls downward, making the cavity expand leaving more room for the lungs to fill with air. • When you exhale, the opposite happens.

Other Functions • Vocal cords: air moves over them to produce sound; folds of tissue in the larynx (voice box). • When you try to talk, the vocal cords squeeze together and cause the lungs to exhale. The air causes them to vibrate, producing sound.

Other Functions • Hiccup: sudden inhalations that cause the diaphragm to contract quickly; causes by eating too fast, sudden temp change, and stress. • All of these functions release water from the body. – When it is cold outside, you can see your “breath” – the water vapor in your breath begins to condense in the cold weather.