End Term 1 Notes PDF

End Term 1 Notes  Nutrition & Digestive System  Nutrition ❖ Living organisms need food. ❖ All food contains nutrients. ❖ Nutrients are substances that provide the energy and materials needed for growth, repair and maintenance of cells and regulation. ❖ Nutrition i...

End Term 1 Notes  Nutrition & Digestive System  Nutrition ❖ Living organisms need food. ❖ All food contains nutrients. ❖ Nutrients are substances that provide the energy and materials needed for growth, repair and maintenance of cells and regulation. ❖ Nutrition is the process by which organisms get food and break it down so it can be used.  Nutrition ❖ Nutrients include: Proteins Carbohydrates Fats Vitamins Minerals Water ❖ Water and minerals are inorganic nutrients which must be obtained from the environment. ❖ Minerals are chemical elements that organisms need for normal functioning.  Energy Content of Food ❖ Energy is provided by the chemical breakdown of carbohydrates, fats and proteins. ❖ The calorie is the unit used to measure energy content of food. ❖ Calorie is defined as the amount of heat needed to raise the temperature of 1 gram of water 1oC.  Nutrients ❖ Humans need the 6 basic nutrients ❖ These nutrients are obtained by eating a healthy diet from the 4 major food groups: Grains and grain products ○ Carbs Dairy and dairy products ○ Fats Fruits and vegetables ○ Fiber Meats and alternatives ○ Protein  Nutrients ❖ Along with the 6 nutrients, humans need fibre. ❖ Fiber is made of cellulose and other indigestible materials found in the cell walls of fruits, vegetables and grains. ❖ Fiber stimulates the muscles of the digestive system to keep foods moving through it.  Vitamins are nutrients that the body needs in small amounts to function and stay healthy  Human Body Systems Circulatory System  This system is also known as the Cardiovascular System. Cardiovascular 🡺 cardio + vascular ○ Cardio from kardia meaning heart ○ Vascular from vascularis that refers to vessels or tubes Circulatory System  The Circulatory System carries blood to and from different places in the body. Materials dissolved in blood: ○ Oxygen ○ Nutrients ○ WasteCirculatory System Heart Circulatory System  Heart The heart is a muscular pump. When it beats it pumps blood to the lungs and around the body.  Heart Parts Function Right Atrium collect the blood Left Atrium Right Ventricle pump the blood out of the heart Left Ventricle Valves prevent the blood from flowing backwards Our circulatory system is a double circulatory system which means it has two circuits (or paths). Circulatory System The first circuit (Heart ↔ Lungs) carries blood to the lungs to be oxygenated and then back to the heart. In the lungs, carbon dioxide is removed from the blood, and oxygen taken up by the hemoglobin in the red blood cells. Circulatory System: Pulmonary Circuit  Circulatory System: Systemic Circuit The second circuit (Body ↔ Heart) carries blood around the body to deliver the oxygen (oxygen-rich blood) and returns de-oxygenated blood to the heart  Blood Vessel There are three types of blood vessel: Arteries Veins Capillaries  Blood Vessel: Artery Carry blood away from the chambers of the heart Have thick muscular walls Have small/narrow passageways for blood Contain blood under high pressure BLOOD BLOOD  Heart The right side of BLOOD the heart pumps BLOOD de-oxygenated blood to the lungs to pick up oxygen.  Heart BLOOD The left side of the BLOOD heart pumps the oxygenated blood from the lungs around the rest of the body.  Blood Vessel: Vein Carry blood to the chambers of the heart Have thin walls Have larger passageways for blood Contain blood under low pressure Have valves to prevent blood flowing backwards BLOOD BLOOD  Blood Vessel: Capillaries Found in the muscles and lungs Microscopic – one cell thick Very low blood pressure Where gas exchange takes place. Oxygen passes through the capillary wall and into the tissues, carbon dioxide passes from the tissues into the blood  What are the different materials found in our blood? Blood  Key Components of Blood Blood has four key components: 1. Plasma 2. Red blood cells 3. White blood cells 4. Platelets  Key Components of Blood Red blood cells Contain hemoglobin which carries oxygen Made in the bone marrow. The more you exercise the more red blood cells are made.  Key Components of Blood White blood cells An important part of the immune system, they produce antibodies and destroy harmful microorganisms (such as bacteria and viruses) Made in the bone marrow Platelets Clump together to form clots Protect the body by stopping bleeding Plasma Fluid part of blood Carries important nutrients, hormones, and waste (such as carbon dioxide)  Color of Blood Both oxygenated and deoxygenated blood are red. Oxygenated blood is brighter and lighter shade of red.  Circulatory System Common Ailment/Illness/Problem High Blood Pressure (Hypertension)  Taking Care of the Circulatory System reduce salt and saturated fats in your diet increase fresh fruit and vegetables intake per day do 30 minutes of moderate activity per day maintain a healthy weight maintain good oral hygiene avoid smoking and drinking too much alcohol  Human Body Systems Respiratory System Respiratory System A system that interacts with the environment and with other body systems to bring oxygen to the body and remove carbon dioxide. Write the missing names of the parts of the respiratory system. Breathing Air is warmed and cleaned as it travels through the mouth and nose. It then passes through the trachea and one of the two bronchi (singular bronchus) into one of the lungs. After passing into the many bronchioles, it finally arrives into some of the millions of tiny sacs called alveoli (singular alveolus). This is where gas exchange takes place – oxygen passes out of the air into the blood, and carbon dioxide passes out of the blood into the air in the alveoli.  What happens to the ribcage, diaphragm and lungs when we inhale? When you inhale: a) The muscles between ribs contract, expanding the rib cage b) The diaphragm contracts, pulling downwards to increase the size of the chest c) Pressure inside the chest is lowered and air moves into the lungs Breathing-Inhale  What happens to the ribcage, diaphragm and lungs when we exhale? When you exhale: a) The muscles between ribs relax, rib cage returns to its original size b) The diaphragm relaxes, moving back upwards, decreasing the size of the chest c) Pressure inside the chest increases and air is forced out Breathing-Exhale Inhaled and Exhaled Air Breathing Inhaled air contains: more oxygen used to produce energy less carbon dioxide than exhaled air Exhaled air which contains: more carbon dioxide produced as a waste product of energy production less oxygen as it has been used in respiration (process to produce energy).  Respiration Respiration is the release of energy from sugars in the muscles. Glucose + oxygen → energy + water + carbon dioxide  Respiration Carbon dioxide is produced as a waste product of cellular respiration and must be removed from the body. Common Respiratory Problems Taking Care of the Respiratory System Avoid cigarette smoke. Protect yourself against air pollution. Eat foods that are rich in protein, vitamins and minerals. Drink plenty of fluids. Exercise regularly – helps keep the lung healthy  During exercise, we breathe faster because our lungs and the respiratory system must provides more oxygen to the blood, thus increases the rate of breathing. Excretory System Other Functions of the kidneys  Urinary Tract Infection (UTI) Urinary Tract stones / Development of cysts Kidney failure Proper Care of the Excretory / Urinary System Sensory Organs and Nervous System The nervous system  Nervous System It consists of the: brain, Spinal cord sensory organs (Peripheral) nerves. brain spinal cord nerves  The central nervous system is the control center of your body. Your brain and the spinal cord are the parts of the central nervous system. Your central nervous system (cns) controls your breathing, heart rate, and the movement of your muscles  The five senses are hearing, sight, smell, taste and touch Sometimes your spinal cord decides what your body does – this is called a reflex action An example of this is when you touch a hot object and you pull your hand back automatically Sense organs Sense organs contain receptors that are sensitive to stimuli (input from the environment) Receptors ○ are groups of specialized cells ○ can detect changes in the environment,which are called stimuli and turn them into electrical impulses ○ are often located in the sense organs, such as the ear, tongue, eye and skin COPY THE Summary TABLE IN YOUR STUDY GUIDE. Sense Sense Stimuli sensitive to organs Skin Touch touch, pressure, pain and temperature Tongue Taste chemicals in food Nose Smell chemicals in the air Eyes Sight light Ears Hearing sound and position of the head WHAT HAPPENS TO YOUR SKIN WHEN YOU TOUCH SOMETHING COLD? Touch: Too cold When we get too cold, our hair muscles pull root hair. This allows the hairs to be upright which traps air. Then the blood flow in the capillaries decreases allowing us to feel a bit warm.  READ THE TEXT BELOW. TAKE TURNS. Touch: Too hot When we get too hot, our hair muscles relax. Our hairs will lie flat so that heat can escape. The sweat secreted by sweat glands will cool the skin by evaporation. The blood flow in capillaries will increase. WHAT ARE THE FOUR TYPES OF TASTE AND ITS LOCATION?  Chemical molecules enter the nose and dissolve in mucous within a membrane called the olfactory epithelium. In humans, the olfactory epithelium is located about 7 cm up and into the nose from the nostrils. Our sense of sight WHAT ARE THE PARTS OF THE EAR? HOW IS SOUND PRODUCED?  The Brain The brain controls voluntary behaviour (walking and thinking) and involuntary responses (heartbeat, blood pressure, eye blinking) The average brain contains nearly 100 billion nerve cells called neurons.  IDENTIFY THE PARTS OF THE BRAIN. What are the areas of the brain? What do the images tell you?  Spinal Cord The spinal cord connects the brain with the rest of the nerves in the body. ○ Is about 44 centimeters 43 cm (female) 45 cm (male) ○ Weighs about 35-40 grams ○ Made up of small bones called vertebrae  Peripheral Nerves The nervous system also includes all of the nerves that lie outside the brain and spinal cord. Nerve cells are called neurons  Typical Structure of a Neuron Neurons are nerve cells. They carry information as tiny electrical signals. branches Long fiber WHAT ARE THE 3 TYPES OF NERVE CELLS? 3 main types of nerve cells/ neurons sensory relay motor neuron neuron neuron  Sensory neuron Carries signals (stimuli) from environment to the receptor cells connected to the central nervous system (CNS)  Motor neuron Carries signals from CNS to effectors (muscles or glands) to bring about movement (muscles) or to bring about secretion of hormone (glands)  Motor neuron Carries signals from CNS to effectors (muscles or glands) to bring about movement of the muscles  Motor neuron gonads Carries signals from CNS to effectors (muscles or glands) to bring about secretion of hormone  Relay neuron Carries messages from CNS to motor neurons to bring about movement or bring about release of hormones. Different neurons working together Types of Actions Effectors An effector is any part of the body that produces the response. Here are some examples of effectors: a muscle contracting to move the arm a muscle squeezing saliva from the salivary gland a gland releasing a hormone into the blood  Voluntary Actions A voluntary action is an action that involves conscious thought (thinking time) ○ you (or the brain) consciously making a decision. Example: You see a friend over at the other side of the room. You wish to attract the attention of that friend of yours so you wave your hand. Voluntary Action (stimulus) (action)  Reflex Actions Reflex actions DO NOT involve conscious thought They happen very quickly. They are rapid to avoid unnecessary damage to the body  FOLLOW THE DIAGRAM BELOW. Reflex Action  Reflex Action This is what happens: 1. Receptor detects a stimulus (change in the environment). 2. Sensory neuron sends signal to relay neuron. 3. Motor neuron sends signal to effector. 4. Effector produces a response.  HOW IS A REFLEX ACTION PRODUCED? Reflex Action (stimulus) (action) Reflex Action 1. The skin detects a stimulus which is the change in temperature. 2. Sensory neurons sends electrical signals to a relay neuron which is located in the spinal cord of the CNS. Relay neurons connect sensory neurons to 3. Motor neurons send electrical impulses to the muscles. 4. Muscle contracts to move the hand away which is the reflex action