unit 10 the human body
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Unit 10 The Human Body. Ch. 37 Circulatory & Respiratory Systems. Functions of the Circulatory System. The human circulatory system consists of the heart, a series of blood vessels, & the blood that flows through them. The Heart. - PowerPoint PPT PresentationTRANSCRIPT
Unit 10 The Human Body
Ch. 37 Circulatory & Respiratory Systems
Functions of the Circulatory System
• The human circulatory system consists of the heart, a series of blood vessels, & the blood that flows through
them
The Heart
• The heart is made almost entirely of muscle, & is a hollow organ about the size of your clenched fist
• Atria - the upper chambers that receive the blood
• Ventricles - the lower chambers that pumps the blood out of the heart
The Heart
• The heart functions as 2 separate pumps• Pulmonary circulation - pathway on the
right side that pumps oxygen-poor blood from the heart to the lungs
The Heart
• Systemic circulation - pathway on the left side
that carries oxygen-rich blood from lungs to the
heart, & the rest of the body
Circulation Through the Heart
• Blood enters the heart through the right & left atria
• It then flows out from the ventricles to either the body or the lungs
• Valves - flaps between the atria & the ventricles, prevent blood from flowing backwards
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Blood Vessels
• Aorta - large blood vessel, carries oxygen-rich blood away from heart to the body
• As blood flows through the circulatory system, it moves through 3 types of blood vessels: arteries, capillaries, & veins
Blood Vessels
• Arteries - vessels that carry blood away from the heart to the tissues of the body– They carry oxygen-rich blood
Blood Vessels
• Capillaries - smallest of the blood vessels• Veins - return oxygen-poor blood to the
heart
Diseases of the Circulatory System
• Cardiovascular diseases, like heart disease & stroke, are among the leading causes of death in the U.S.
• High blood pressure & atherosclerosis are 2 of the main causes of cardiovascular disease
Diseases of the Circulatory System
• Atherosclerosis - condition where fatty deposits, called plaque, build up on the inner walls of the arteries– Can cause heart attacks & strokes
Diseases of the Circulatory System
• High blood pressure, hypertension, increases the rate of heart attack & stroke
• High blood pressure occurs when deposits of fat build up on the artery walls
Blood & the Lymphatic System
• Blood is a type of connective tissue • It collects oxygen from the lungs, nutrients
from the digestive tract, & waste products from tissues
• Blood helps regulate body temperature• The components that make up blood help
fight infection, & repair damaged blood vessels
Blood Plasma
• The human body has 4-6 liters of blood, or 8% of the total body mass
• 45% of blood consists of cells, that are suspended in the other 55%, plasma
• Plasma - 90% water, 10% dissolved gases, salts, nutrients, enzymes, hormones, waste products, & proteins
Blood Plasma
Blood Cells
• The cellular portion of blood consists of red blood cells, white blood cells, & platelets
Blood Cells
• Red blood cells transport oxygen, are the most numerous, & get their color from hemoglobin– Hemoglobin - iron-containing protein
that binds oxygen in the lungs & transports it to tissues throughout the body where oxygen is released
Blood Cells
• White blood cells are the “army” of the circulatory system - they guard against infection, fight parasites, & attack bacteria– Lymphocytes - a special class of white blood
cells, produce antibodies that are proteins that help destroy pathogens
Blood Cells
• Blood clotting is made possible by plasma proteins
& cell fragments called platelets
• Platelets - large bone marrow cells that have broken into small fragments
The Lymphatic System
• A network of vessels, nodes, & organs called the lymphatic system, collects the fluid that is lost by the blood & returns it back to the circulatory system
• Lymph - fluid collected by the system
The Lymphatic System
• The spleen is an organ whose main function is to destroy damaged red blood cells & platelets
• T cells (white blood cells) mature in the thymus gland, which produces hormones that promote their development
The Lymphatic System
What Is Respiration?
• At the cellular level, respiration takes place in the mitochondria
• It releases energy from the breakdown of food molecules in the presence of oxygen
What Is Respiration?
• At the level of the organism, respiration means the process of gas exchange - the release of carbon dioxide & the uptake of oxygen between the lungs & the environment
The Human Respiratory System
• The basic function of the human respiratory system is to bring about the exchange of oxygen & carbon dioxide between the blood, air, & tissues
• The respiratory system consists of the nose, pharynx, larynx, trachea, bronchi, & lungs
The Human Respiratory System
• Pharynx - passageway for both air & food• Larynx - top of trachea, vocal cords• Trachea - windpipe, receives
air from pharynx
The Human Respiratory System
• Bronchi - 2 large passageways in the chest cavity, each leads into 1 of the lungs
• Inside the lungs, the bronchi divide into even smaller tubes, called bronchioles
• Alveoli - tiny air sacs at the ends of the bronchioles, where gas exchange takes place
The Respiratory System
Gas Exchange
• There are about 150 million alveoli in each healthy lung
• Oxygen diffuses across the membrane of the alveoli into the capillaries, wrapped around the outside of the alveoli
• At the same time, carbon dioxide diffuses from the blood in the capillaries, into the alveoli, to be excreted
Gas Exchange
Breathing
• Breathing is the movement of air into & out of the lungs
• Diaphragm - large, flat muscle at the bottom of the cavity
Tobacco & the Respiratory System
• The upper part of the respiratory system is able to filter out dust & foreign particles that could damage the lungs
• Smoking tobacco damages that protective layer
Tobacco & the Respiratory System
• Tobacco contains nicotine, carbon monoxide, & tar
• Nicotine - a stimulant drug that increases heart rate & blood pressure
Tobacco & the Respiratory System
• Carbon monoxide is a poisonous gas that blocks the transport of oxygen by hemoglobin in the blood
• Tar contains a # of compounds that have been shown to cause cancer
Tobacco & the Respiratory System
• Smoking reduces life expectancy• Only 30% of male smokers live to age 80,
but 55% of male nonsmokers live to that age
• Smoking can cause respiratory diseases like: chronic bronchitis, emphysema, & lung cancer
Tobacco & the Respiratory System
• Chronic bronchitis occurs when the bronchi become swollen & clogged with mucus
• Emphysema - the loss of elasticity in the tissues of the lungs, making breathing very difficult
Tobacco & the Respiratory System
• Lung cancer is deadly because its cells can spread to other locations
• By the time lung cancer is detected, it has spread to dozens of other places
Tobacco & the Respiratory System
• Smoking is also a major cause of heart disease, it constricts, or narrows, the blood vessels
• There is a drastic change in body temp. & in circulation immediately after smoking a cigarette