Survey
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
The Human Body Part II Chapters 37-39 The Respiratory System Ch. 37-3 Respiration is the process by which oxygen & carbon dioxide are exchanged between cells, the blood, and air in the lungs • The Human Respiratory System: – Exchanges oxygen and CO2 between the blood, air, and tissues The Respiratory System Ch. 37-3 • The Respiratory System Consists of: – Nose, Pharynx ,Trachea, Bronchi, Lungs • How it works: – Air moves from the pharynx into the trachea – Air passes from the trachea into two large passageways called the bronchi (singular= bronchus) – Each bronchus leads into one of the lungs – Within each lung, the bronchus subdivides into smaller passageways called the bronchioles – Bronchioles continue to subdivide until they reach tiny air sacs called alveoli – Oxygen crossed over from the alveolus into thin capillaries and the blood stream – CO2 crosses over from the blood back into the alveolis to be disposed of as waste The Respiratory System Ch. 37-3 • Generally speaking, the brain controls breathing • The diaphragm, located at the bottom of the chest cavity, contracts and allows air to rush into the lungs • When the diaphragm relaxes, air is forced back out of the lungs • The rate of breathing is controlled by the level of CO2 in the blood • The level of CO2 is measured by the medulla oblongata in the brain • As CO2 levels rise the medulla oblongata sends nerve impulses to the diaphragm resulting in the contractions that make us breath in and out. The Respiratory System Ch. 37-3 • Tobacco smoke harms the respiratory system • Tobacco smoke contains: nicotine, tar, and carbon monoxide – Nicotine is a stimulant that increased the heart rate and blood pressure – Tar contains substances that cause cancer – Carbon monoxide is a poisonous gas that blocks the transport of oxygen • Smoking can also cause Emphysema Food and Nutrition Ch. 38-1 • The energy to perform actions, as well as the materials from which body cells and tissues are made comes from food • The energy available in foods can be measured by calories – The # of calories you need each day depends on your size & level of activity • Nutrients are substances in food that supply energy and raw materials the body uses for growth, repair, and maintenance Food and Nutrition Ch. 38-1 • Carbohydrates are the main source of energy for the body– they include: – Sugars, starches, and fiber • Fatty acids form fat which is needed to make cell membranes and certain hormones • Proteins are formed by amino acids and are needed for growth and repair of the body • Many proteins are also hormones Food and Nutrition Ch. 38-1 • Vitamins are organic molecules that help regulate the body • Minerals are inorganic molecules that perform vital functions in the body – EX: Calcium & iron Food and Nutrition Ch. 38-1 • The Food Guide Pyramid can help people select a balanced diet – Classifies food into 6 groups – Foods at base of pyramid should make up major portion of your diet – Foods at top of pyramid should be consumed in small amounts The Process of Digestion Ch. 38-2 • The function of the digestive system is to break down food into simpler molecules that can be absorbed & used by the cell • Human digestive system includes: – Mouth, pharynx, esophagus, stomach, small intestine, large intestine, salivary glands, pancreas, and liver – Digestions starts in the mouth Food and Nutrition Ch. 38-1 • The teeth tear & crush food • Salivary glands secrete saliva: – Amalyse is enzyme found in saliva that breaks chemical bonds between the sugar monomers in starches – This begins process of chemical digestion • From the mouth, food passes through the pharynx into the esophagus (passage that carreies food between the pharynx and the stomach) Food and Nutrition Ch. 38-1 • Food from the esophagus empties into the stomach • Glands in the stomach produce an acid and the enzyme pepcin – Stomach churning, along with the acid and enzyme breaks down food into a soft partially digested mixture called chyme • Chyme passes into the small intestine (where most chemical digestion and absorption of food occurs) Food and Nutrition Ch. 38-1 • Enzymes from the pancreas help digest starch, protein and fat • A liquid called bile from the liver helps break up fat droplets • Nutrients are absorbed through the lining of the small intestines – Villi (small fingerlike projections) found in the small intestines increase the surface are of the small intestines and aide in absorbtion Food and Nutrition Ch. 38-1 • Chyme next enters the large intestine where water is removed from digested material • After most of the water has been removed, remaining waste is passed out of the body • Digestive Disorders include: – Peptic ulcers= caused by bacteria – Diarrhea= when too little water is removed – Constipation= when too much water is removed The Excretory System Ch. 38-3 • The function of the excretory system is to help maintain homeostasis by removing wastes – Wastes like CO2 and urea are produced during normal metabolism – The main organs of excretory system are the kidneys: • They remove waste products from blood, maintain blood pH, and control water content of blood The Excretory System Ch. 38-3 • 2 kidneys are located in the lower back: – Blood containing waste enters kidneys – Both useful substances and wastes are removed from the blood by filtration – Some of the substances are later returned to the blood – Wastes are excreted – The purified blood leaves the kidneys and returns to circulation – The fluid that remains is called urine– which contains urea, excess salts & other substances The Excretory System Ch. 38-3 • A tube called the ureter leaves each kidney and carries urine to the bladder (a saclike organ that stores urine) • Urine passes from the body through a tube called the urethra. • Kidneys are controlled by hormones and concentration of the blood • A person can survive with one kidney – If both kidneys fail, a person must undergo dialysis to survive – Dialysis purifies blood by passing it through a filtering machine The Endocrine System Ch. 39-1 • The endocrine system consists of gland that release hormones into the bloodstream – Hormones are chemicals released from one area of the body that travel throughout the body to affect cells elsewhere – Hormones bind to chemical receptors on cells called target receptors • The endocrine system is made up of glands – A gland is an organ that releases a secretion or hormone – There are endocrine and exocrine glands – Exocrine glands release secretions directly into tissues and organs • EX: Sweat glands The Endocrine System Ch. 39-1 • There are two types of hormones: – Steroid hormones= can cross cell membranes, enter the nucleus and turn cells on and off – Nonsteroid hormones= cannot cross cell membranes • All cells also produce hormonelike substances called prosaglandins that affect only NEARBY cells The Endocrine System Ch. 39-1 • The endocrine system is regulated by feedback mechanisms that help maintain homeostasis • Complementary Hormone Action= 2 hormones with opposite effects may work together to maintain homoestasis – EX: thyroid hormone and thyroid stimulating hormone Human Endocrine Glands Ch. 39-2 • Human endocrine glands include: – Pituitary Gland= controls actions of other endocrine glands – Hpothalamus= Controls pituitary gland – Thyroid Gland= Regulates metabolism – Parathyroid Glands= Regulates calcium levels in blood – Adrenal Glands= Produce hormones to help deal with stress – Pancreas= Produces insulin to keep blood sugar stable – Reproductive Glands= Produce gametes (egg & sperm) The Reproductive System Ch. 39-3 • Sex hormones are produces by gonads of an embryo cause embryo to become either male or female • Sex hormones cause puberty to occur between ages 9 – 15 • At end of puberty reproductive organs are fully developed and able to function The Reproductive System Ch. 39-3 • The male reproductive system produces and delivers sperm • Main organs of male reproductive system are: – Testes= produce sperm in tiny tubes called seminiferous tubulues – Scrotum= hold testes – Vas Deferens= first tube sperm travel through – Urethra=Final tube that allows sperm to exit the body from the penis The Reproductive System Ch. 39-3 • The main function of the female reproductive system is to produce eggs and prepare the female body to nourish an embryo • Main organs of the female reproductive system are: – Ovaries: Produce eggs – Follicles: cluster of cells found in ovaries that surround egg and help it mature – Fallopian Tube: Egg travels through here where it can be fertilized if sperm are present – Uterus: Final resting place of egg – Vagina: Connects uterus to the outside of the body The Reproductive System Ch. 39-3 • One egg develops each months during the menstrual cycle that is controlled by hormones • There are 4 phases to the menstrual cycle: – Follicular Phase= egg matures in the follicle and the uterus is prepared to receive a fertilized egg – Luteal Phase= Follicle turns into structure called corpus luteum – Fertilization= results in implantation in the uterus • No fertilization results in menstration – Menstration= the lining of the uterus falls away and exits the body through the vagina • Will not occur if the egg has been fertilized Fertilization and Development Ch. 39-4 • Fertilization is the process of a sperm joining an egg • A fertilized egg is called a zygote • A week after fertilization, a blastocyst (hollow ball the zygote becomes) implants itself in the lining of the uterus • The blastocyst differentiates and becomes an embryo • As the embryo develops, membranes also form to protect and nourish it and help remove waste – EX: Placenta forms and provides nutrients to the fetus from the mother Fertilization and Development Ch. 39-4 • After 8 weeks of development the embryo is called a fetus • By the end of 3 months, most of the major organs are formed • The last 6 months are used for growth and maturation of fetal organs • Childbirth results when hormones cause the mother’s uterus to contract • Contractions push the baby from the mother’s uterus and out through the vagina Fertilization and Development Ch. 39-4 • Twins are born if more than one egg was fertilized (fraternal twins), or if the zygote splits into two embryos during early development (identical twins) • Growth and development continue throughout infancy and childhood • Adolescence begins with puberty and ends with adulthood • The first signs of aging usually appear in the 30’s