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30.3 The Heart and Circulation
Functions of the Circulatory System
– collecting waste materials– maintaining body temperature
– transporting blood, gases, nutrients
37.1 The Circulatory System
30.3 The Heart and Circulation
The circulatory system moves blood to all parts of the body.
• Circulatory system includes - heart- blood vessels- blood
37.1 The Circulatory System
30.3 The Heart and Circulation
KEY CONCEPT The heart is a muscular pump that moves the blood through two pathways.
NORMAL HUMAN HEART
37.1 The Circulatory System
30.3 The Heart and Circulation
left atrium
left ventricle
right atrium
right ventricle
• The heart has four chambers:- 2 atria: right & left atrium (upper collecting chambers)- 2 ventricles: right & left ventricles (lower pumping
chambers)
• The heart is made up of cardiac muscle.
37.1 The Circulatory System
30.3 The Heart and Circulation
aortic valve
left atrium
mitral valve
left ventricle
septum
pulmonary valve
right atrium
tricuspid
right ventricle
• The heart is divided into two sides by the septum– Right side = pumps deoxygenated blood to lungs– Left side = pumps oxygenated blood to body
• One-way valves separate chambers and prevent backflow of blood.
37.1 The Circulatory System
30.3 The Heart and Circulation
The heart pumps blood through two main pathways. • Pulmonary circulation occurs between the heart and the
lungs.• Systemic circulation occurs between the heart and the rest
of the body.
37.1 The Circulatory System
30.3 The Heart and Circulation
• Blood flows through the heart in a specific pathway.
1
2 4
3
37.1 The Circulatory System
30.3 The Heart and Circulation
Blood flow through the heartSuperior / Inferior Vena Cava (biggest veins)right atriumright ventricle pulmonary arteryto the lungs (pick up O2)pulmonary veinleft atriumleft ventricleaorta
(biggest artery)to the rest of the body
Oxygenated blood
Deoxygenated blood
37.1 The Circulatory System
30.3 The Heart and Circulation 37.1 The Circulatory System
30.3 The Heart and Circulation
KEY CONCEPT The circulatory system transports materials throughout the body.
37.1 The Circulatory System
30.3 The Heart and Circulation
Arteries, veins, and capillaries transport blood to all parts of the body.
• Arteries carry blood away from the heart.– blood under great pressure– thicker, more muscular walls
ARTERY VEINCAPILLARIES
arteriole venule
endothelium
connective tissuesmooth muscle
valve
37.1 The Circulatory System
30.3 The Heart and Circulation
• Circulatory diseases affect mainly the heart and the arteries.– artery walls become thick and inflexible– plaque blocks blood flow in arteries
37.1 The Circulatory System
30.3 The Heart and Circulation
• Veins carry blood back to the heart.– blood under less pressure– thinner walls, larger diameter– valves prevent backflow
ARTERY VEINCAPILLARIES
arteriole venule
endothelium
connective tissuesmooth muscle
valve
37.1 The Circulatory System
30.3 The Heart and Circulation
• Varicose veins are enlarged veins that are raised abovethe skin.
• Valves in the veins do not function properly causing blood to remain in the veins.
37.1 The Circulatory System
30.3 The Heart and Circulation
• Capillaries move blood between veins, arteries, and cells.- thinnest blood vessels- gas exchange take place
ARTERY VEINCAPILLARIES
arteriole
endothelium
connective tissue
smooth muscle
venule
valve
37.1 The Circulatory System
30.3 The Heart and Circulation
• Blood pressure is a measure of the force of blood pushing against artery walls. – systolic pressure:
left ventricle contracts
– diastolic pressure: left ventricle relaxes
• High blood pressure can precede a heart attack or stroke.
37.1 The Circulatory System
30.5 Blood
KEY CONCEPT Blood is a complex tissue that transports materials.
37.2 Blood and The Lymphatic System
30.5 Blood
Blood is composed mainly of cells, cell fragments, and plasma.
• Whole blood is made up of different materials.– plasma– red blood cells – white blood cells – platelets
red blood cells,white blood cells,and platelets
plasma
37.2 Blood and The Lymphatic System
30.5 Blood
Blood is composed mainly of cells, cell fragments, and plasma.
1. Plasma– approx. 55% of blood volume– Carries nutrients (amino acids, glucose)
and wastes– 90% water– Remainder consists of minerals,
proteins, and other compounds– Proteins assist in clotting, maintaining
water balance and fighting disease
37.2 Blood and The Lymphatic System
30.5 Blood
• Protein markers define blood types and Rh factors.
– ABO blood group the most common– Rh factor can be negative or positive– blood types must be compatible for transfusions
37.2 Blood and The Lymphatic System
30.5 Blood
2) Red blood cells – make up 40-45 % of all blood cells– produced in bone marrow– transport oxygen to cells and carry away carbon dioxide– have no nuclei and contain hemoglobin (binds with O2)
37.2 Blood and The Lymphatic System
30.5 Blood
3. White Blood Cells - approx 1% along with platelets of blood volume- body’s main defense against disease- some “eat” pathogens by phagocytosis- some are lymphocytes (B-cells and T-cells) involved inimmune response
red blood cell
platelet
white blood cell
37.2 Blood and The Lymphatic System
30.5 Blood
red blood cell
platelet
white blood cell
4) Platelets
– cell fragments that aid in blood clotting
37.2 Blood and The Lymphatic System
30.5 Blood
• Platelets help form clots that control bleeding.
platelets
fibrin
red blood cell
white blood cell
37.2 Blood and The Lymphatic System
30.2 Respiration and Gas Exchange
KEY CONCEPT The respiratory system exchanges oxygen and carbon dioxide.
37.3 The Respiratory System
30.2 Respiration and Gas Exchange
– picks up O2 from inhaled air– expels CO2 and water– where gas exchange takes place
nose
sinus
mouthepiglottis
trachea
lungs
Functions of the respiratory system
37.3 The Respiratory System
30.2 Respiration and Gas Exchange
Structures of the Respiratory System
37.3 The Respiratory System
Nasal cavity
pharynxlarynx
esophagustrachea
right lung
left lung
bronchusbronchiole
diaphragm heart
30.2 Respiration and Gas Exchange
Pathway of Air
1) Nasal Cavity (nose)- mucus warms and moistens air to prevent damage to
lungs- cilia filter air and trap
particles2) Pharynx
- directs air into respiratory tract and food into digestive tract
3) Larynx (voicebox)- sound is produced when air is forced through vocal cords
37.3 The Respiratory System
30.2 Respiration and Gas Exchange
Pathway of Air
4) Trachea (windpipe)- located in the center of chest cavity- tube made of rings of cartilage
5) Bronchi/Bronchioles- trachea branches into left and right bronchus- each bronchus branches off
into smaller bronchioles6) Alveoli
- tiny air sacs at the end of bronchioles
- capillaries surround alveoli for gas exchange (CO2/O2)
37.3 The Respiratory System
30.2 Respiration and Gas Exchange
Pathway of Air7) Lungs
- right lung has 3 lobes; left lung has 2 lobes- located inside thoracic (chest) cavity- entire cavity is enclosed by the pleura= double membranes that secrete mucus to
reduced friction during breathing
Healthy lungs Smoker’s lungs
37.3 The Respiratory System
30.2 Respiration and Gas Exchange
Gas exchange occurs in the alveoli of the lungs. • Oxygen and carbon dioxide are carried by the blood to and
from the alveoli.– oxygen diffuses from alveoli into capillary – oxygen binds to hemoglobin in red blood cells – carbon dioxide diffuses from capillary into alveoli
ALVEOLI
capillaries
GAS EXCHANGES
alveolus
capillary
co2
o2
Co2 diffusesinto alveolus.
O2 diffusesinto blood.
37.3 The Respiratory System
30.2 Respiration and Gas Exchange
Gas exchange occurs in the alveoli of the lungs. • Breathing is regulated by the brain stem.
midbrainpons
medulla oblongata
spinal chord
37.3 The Respiratory System
30.2 Respiration and Gas Exchange
Mechanisms of breathing• Breathing involves the diaphragm and muscles of the
rib cage. • diaphragm = a layer muscle tissues beneath the lungs
that contract or relax to help in breathing
Air inhaled.
Muscles contract andrib cage expands.
Diaphragm flattensand moves downward.
Air exhaled.
Muscles andrib cage relax.
Diaphragm relaxesand rises.
Inhalation Exhalation
37.3 The Respiratory System
30.2 Respiration and Gas Exchange
Respiratory diseases interfere with gas exchange.
• Lung diseases reduce airflow and oxygen absorption.– Emphysema destroys
alveoli.– Asthma constricts
airways.– Cystic fibrosis produces
sticky mucus.
• Smoking is the leading cause of lung diseases.
37.3 The Respiratory System
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