AlTamayuz in Science G6th First Term PDF

AlTamayuz in Science G6th First Term Prepared by Dr/ Zeinab Salah ‫للتواصل وحجز مجموعات اﻷونﻼين‬ Tel: 01014731686 Dr/ Zeinab Salah 0 Tel: 01014731686 ...

AlTamayuz in Science G6th First Term Prepared by Dr/ Zeinab Salah ‫للتواصل وحجز مجموعات اﻷونﻼين‬ Tel: 01014731686 Dr/ Zeinab Salah 0 Tel: 01014731686  Unit 1: What is a System? Concept 2: The Body as a System Interaction between body systems  The whole body consists of group of different systems perform different functions.  All body systems interact and work together in an integrated way (as one whole body system) to help the body respond to the danger (or run away from it), get energy, and keep the body healthy.  Example 1: When you feel nervous (or stressed), heartbeats increase, the body may sweat, and you may feel pain in stomach.  Example 2: In dangerous situations, there is an interaction between all body systems to respond to the danger as following: 1) Eyes send the information to the brain to perform the proper action. 2) The brain (nervous system) sends a signal to muscles (muscular system) to contract and allow body to face the danger.  Each system depends on all other systems to do its functions, so if one system doesn’t do its function, the other systems will not be able to do their functions as following: 1) The nervous system depends on digestive system and circulatory system to do its function where: a) Digestive system digests food into nutrients. b) The circulatory system transfers nutrients through blood to the nerve cells to get its needed energy. 2) The digestive system and circulatory system depend on nervous system, where the nervous system controls the movement of muscles of stomach in digestive system and muscles of heart in circulatory system. 3) The skeletal system depends on the digestive system, where the digestive system provides the skeletal system with nutrients needed for growth and fracture healing. Dr/ Zeinab Salah 1 Tel: 01014731686 How are cells organized to build the human body  Cells in human body differ in shape and size, because cells must be specialized to perform specific function.  Cells can be organized to build larger systems in human body.  Ex: Muscle cells can be organized to build muscular system where: 1) Muscle cells are bundled (collected) together to form muscle tissue. 2) Bundles of muscle tissues are organized to form muscle (an organ). 3) Group of organs are organized to form muscular system in which each organ perform specific role to allow the system to do its function.  Characteristics of Muscle cells: 1) They are cells in the form of long fibers to allow movement. 2) They must be able to store and use energy quickly. 3) The size of muscle cells is very small, so they don’t work alone and must work with thousands of other cells to be effective. The Musculoskeletal system  Musculoskeletal system: is the system which helps the body to move and consists of two systems which are: Muscular and Skeletal systems.  Musculoskeletal system consists of group of different organs which are: bones, muscles, ligaments, tendons, and cartilages.  Muscular system and Skeletal system work together to allow the movement of the body as following: 1) Skeletal muscles are muscles attached to bones of the skeletal system. 2) Skeletal muscles contract and relax to allow bones to move. 3) The skeletal muscles work in pairs and move in opposite directions. 4) The muscle can only exert force when it contracts to move the bone in only one direction. Dr/ Zeinab Salah 2 Tel: 01014731686  Example: when you lift a bag by your hand the arm moves due to contraction and relaxation of skeletal muscles where: 1) The forearm moves up towards the shoulder (bend your elbow) when the front muscle of upper arm contracts (shorten in length) and the back muscle relax. 2) The forearm moves down away from the shoulder (straighten your elbow) when the front muscle of upper arm relaxes and the back muscle contract. Types of muscles Voluntary muscles Involuntary muscles They are muscles that you can They are muscles that move control their movements. automatically and you can’t control their movements. Examples: Examples: 1) Skeletal muscles: such as muscles 1) Cardiac muscle. of upper arm, neck and forearm. 2) Eye muscles. 2) Abdomen muscles. First: Involuntary muscles 1) Cardiac muscle  Cardiac muscle is a type of involuntary muscles that form the heart.  Cardiac muscle contracts and relaxing without stopping to allow the heart pumps the blood carrying oxygen to all the body cells. Dr/ Zeinab Salah 3 Tel: 01014731686  2) Eye muscles  Eye muscles are a type of involuntary muscles that allow you blink many times in one minute.  Eye muscles contract when you close your eyelid.  Note: the eye muscles that surround the eyeball are considered as voluntary muscles that help you move your eyes in different directions. Second: Voluntary muscles 1) Skeletal muscles  All muscles can do the function of movement by contraction.  When a pair (two) of skeletal muscles performs an action, one muscle contracts while the other relaxes. 1) Upper arm muscles: bending your elbow depends on two different voluntary muscles which are front muscle and back muscle. 2) Neck muscles: moving your head up and down depends on two neck voluntary muscles. 3) Forearm muscles: turning your hand over (palm up) and down (palm down) depends on two forearm voluntary muscles. 2) Abdomen muscles  There are two abdomen voluntary muscles on each side of your body called waist muscles.  When you twist your waist to one side, the two waist muscles in this side contract together, while the two waist muscles in the other side relax together. Dr/ Zeinab Salah 4 Tel: 01014731686 Systems work together  Many of tasks you perform daily require different systems to work together such as: 1) Endocrine system 2) Circulatory system 3) Respiratory system 4) Digestive system 5) Excretory system 1) Endocrine system  Endocrine system is the system that consists of glands to secrete hormones that control body temperature and pressure.  In dangerous situations, endocrine system secretes hormones that control the body respond and affects other body systems to face the danger such as: 1) Contraction of muscles (musculoskeletal system). 2) Increasing heartbeats (circulatory system). 3) Increasing of breathing rate (respiratory system). 2) Circulatory system  Circulatory system is the system that transports blood which carries gases, nutrients, and hormones throughout the body.  Circulatory system consists of heart muscle and blood vessels that allow blood to flow through the body.  There are 3 types of blood vessels: arteries, veins and blood capillaries.  In dangerous situations, heartbeats increases to allow heart pump more blood to the muscles and the other organs, so blood pressure increases. Dr/ Zeinab Salah 5 Tel: 01014731686  3) Respiratory system  Respiratory system is the system that provides the body with oxygen gas and gets rid of carbon dioxide gas.  Respiratory system consists of lungs, diaphragm and airways (such as trachea and bronchi).  During respiration process the diaphragm muscle: 1) Contracts, so lungs take in air rich in oxygen gas (inhalation). 2) Relaxes, so lungs release air rich in carbon dioxide gas (exhalation).  Respiratory system provides different organs with oxygen which is carried by bloodstream from lungs (oxygenated blood).  In dangerous situations, heartbeats increase and respiration rate increases to send more oxygenated blood to muscles and brain. 4) Digestive system  Digestive system is the system that converts complex food into simpler substances that the body can use for energy and growth through process called digestion process.  Some of the simpler substances are used inside the cell in cellular respiration process.  Complex food contains different nutrients such as carbohydrates, fats and proteins.  Nutrients that are produced from digestion process are transported through circulatory system to different organs.  Cells can use some nutrients such as glucose sugar at once to get their needed energy.  Some nutrients are stored as sugars and fats as following: 1) Glucose sugar can be converted into a storage substance called glycogen and stored in liver and muscles. 2) Liver and muscles can convert glycogen into glucose sugar again when body need energy as in dangerous situations. Dr/ Zeinab Salah 6 Tel: 01014731686  Steps of digestion process Mouth  The digestion begins in mouth.  Jaw muscles help teeth to chew food into smaller parts.  During chewing, saliva softens (moistens) the food and starts the chemical breakdown of food.  Saliva: is a liquid contains enzymes (chemicals) and is secreted by endocrine system in mouth. Stomach  After swallowing food, muscles push it into esophagus then to stomach.  The continuous churning movement of stomach and secreting the digestive fluids (that contain an acid and some enzymes) inside stomach allow more food breakdown. Small  Pancreas and gallbladder secrete enzymes that help in intestine chemical breakdown of food once it moves to small intestine.  The walls of the small intestine absorb digested food (nutrients) through blood vessels to carry them to all body parts. Large  Undigested food is passed to colon as soupy mixture. intestine  Colon absorbs more water from undigested food that become (Colon) solid mass called feces or stool.  Stool is stored inside rectum until it leaves the body through anus (a muscular opening at the end of rectum). 5) Excretory system  Excretory system is responsible for storing and getting rid of waste materials produced from cells.  Excretion process: is the process of collecting and removing the waste products resulting from burning food inside the body cells through their membranes.  If the body doesn’t get rid of wastes, it will get sick.  Excretion process occurs by 3 parts of the body which are: 1) Skin. 2) Respiratory system. 3) Urinary system. Dr/ Zeinab Salah 7 Tel: 01014731686 1) Skin Helps in excretion of wastes in the form of sweat through pores in the skin. 2) Respiratory Helps in excretion of carbon dioxide gas during system exhalation. 3) Urinary system Removes waste materials from the blood in the form of urine. Human urinary system  Human urinary system consists of: 1) Two Kidneys. 2) Two Ureters. 3) Bladder. 4) Urethra.  Kidneys are considered as a filtering system of the blood.  Urea: is one of the most important wastes that removed by kidney and formed due to breakdown of proteins inside the body cells. Kidneys  The blood which carries the wastes enters each kidney through a large artery.  Kidney contains many nephrons (a microscopic filter) that clean and filter the blood up to 300 times a day to remove harmful materials from the body.  After filtration, urine is formed from urea, water and other waste materials. Ureters The tubes that transport urine from kidneys to bladder. Bladder Urine is collected in bladder until it is expelled out of the body. Urethra The tube from which urine is expelled out of the body.  Urination: is the process of expelling urine out of the body.  Blood cells and proteins are too large to pass through the nephron so they stay in the blood.  Engineers design special devices for people whose kidneys are not working properly to work instead of kidney organ.  Studying a kidney model instead of a real kidney save time, money and effort and can save people’s life. Dr/ Zeinab Salah 8 Tel: 01014731686 Diabetes disease  Diabetes disease is one of the disorders of the endocrine system.  Pancreas is one of the organs of the endocrine system that produce insulin hormone.  Insulin hormone regulates the level of sugar in the blood that the body can use for energy.  If Pancreas doesn’t do its function properly, person will be infected with diabetes disease where: 1) Person will be unable to make or use insulin. 2) Sugar stays in the blood causing many problems.  Infected people must monitor the level of blood sugar and not allow it to get too low or too high.  Technology to treat diabetes:  Diabetics can control the blood sugar level by: 1) Taking regular shots (doses) of insulin. 2) Using insulin pump device which is attached to the body and automatic injects the body with insulin (external pump). 3) Researchers now are working to develop an artificial pancreas, which will be internal organ that pumps insulin as needed. Dr/ Zeinab Salah 9 Tel: 01014731686