Download 30.3 The Heart and Circulation 37.1 The Circulatory System

37.1
System
30.3 The Circulatory
Heart and Circulation
Functions of the Circulatory System
– transporting blood, gases,
nutrients
– collecting waste materials
– maintaining body temperature
37.1
System
30.3 The Circulatory
Heart and Circulation
The circulatory system moves blood to all parts of the
body.
• Circulatory system includes
- heart
- blood vessels
- blood
37.1
System
30.3 The Circulatory
Heart and Circulation
KEY CONCEPT
The heart is a muscular pump that moves the blood
through two pathways.
NORMAL HUMAN HEART
37.1
System
30.3 The Circulatory
Heart and Circulation
• The heart is made up of cardiac muscle.
• The heart has four chambers:
- 2 atria: right & left atrium (upper collecting chambers)
- 2 ventricles: right & left ventricles (lower pumping
chambers)
left atrium
right atrium
left ventricle
right ventricle
37.1
System
30.3 The Circulatory
Heart and Circulation
• 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.
pulmonary valve
aortic valve
left atrium
right atrium
mitral valve
left ventricle
tricuspid
right ventricle
septum
37.1
System
30.3 The Circulatory
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
System
30.3 The Circulatory
Heart and Circulation
• Blood flows through the heart in a specific pathway.
1
3
2
4
37.1
System
30.3 The Circulatory
Heart and Circulation
Blood flow through the heart
Superior / Inferior Vena Cava
(biggest veins)
Deoxygenated blood
Æ right atrium
Æ right ventricle
Æ pulmonary artery
Æ to the lungs (pick up O2)
Æ pulmonary vein
Æ left atrium
Æ left ventricle
Oxygenated blood
Æ aorta
(biggest artery)
Æ to the rest of the body
37.1
System
30.3 The Circulatory
Heart and Circulation
37.1
System
30.3 The Circulatory
Heart and Circulation
KEY CONCEPT
The circulatory system transports materials
throughout the body.
37.1
System
30.3 The Circulatory
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
endothelium
smooth muscle
valve
connective tissue
ARTERY
VEIN
CAPILLARIES
arteriole
venule
37.1
System
30.3 The Circulatory
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
System
30.3 The Circulatory
Heart and Circulation
• Veins carry blood back to the heart.
– blood under less pressure
– thinner walls, larger diameter
– valves prevent backflow
endothelium
smooth muscle
valve
connective tissue
ARTERY
VEIN
CAPILLARIES
arteriole
venule
37.1
System
30.3 The Circulatory
Heart and Circulation
• Varicose veins are enlarged veins that are raised above
the skin.
• Valves in the veins do not function properly causing blood
to remain in the veins.
37.1
System
30.3 The Circulatory
Heart and Circulation
• Capillaries move blood between veins, arteries, and cells.
- thinnest blood vessels
- gas exchange take place
endothelium
smooth muscle
valve
connective tissue
ARTERY
VEIN
CAPILLARIES
arteriole
venule
37.1
System
30.3 The Circulatory
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.
37.2
30.5 Blood and The Lymphatic System
KEY CONCEPT
Blood is a complex tissue that transports materials.
37.2
30.5 Blood and The Lymphatic System
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
plasma
red blood cells,
white blood cells,
and platelets
37.2
30.5 Blood and The Lymphatic System
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
30.5 Blood and The Lymphatic System
• 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
30.5 Blood and The Lymphatic System
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
30.5 Blood and The Lymphatic System
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 in
immune response
red blood cell
platelet
white blood cell
37.2
30.5 Blood and The Lymphatic System
4) Platelets
– cell fragments that aid in blood clotting
red blood cell
platelet
white blood cell
37.2
30.5 Blood and The Lymphatic System
• Platelets help form clots that control bleeding.
platelets
fibrin
white
blood cell
red blood cell
37.3
The Respiratory
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
Functions of the respiratory system
– picks up O2 from inhaled air
– expels CO2 and water
– where gas exchange takes place
sinus
nose
mouth
epiglottis
trachea
lungs
37.3
The Respiratory
System
30.2 Respiration
and Gas
Exchange
Structures of the Respiratory System
Nasal cavity
pharynx
larynx
esophagus
trachea
right lung
bronchus
left
lung
bronchiole
diaphragm
heart
37.3
The Respiratory
System
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
particles
2) 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 bronchioles
6) 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 Air
7) 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
GAS EXCHANGES
capillary
alveolus
co2
Co2 diffuses
into alveolus.
o2
capillaries
O2 diffuses
into 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.
midbrain
pons
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
Inhalation
Air inhaled.
Exhalation
Air exhaled.
Muscles and
rib cage relax.
Muscles contract and
rib cage expands.
Diaphragm flattens
and moves downward.
Diaphragm relaxes
and rises.
37.3
The Respiratory
System
30.2 Respiration
and Gas
Exchange
Respiratory diseases interfere with gas exchange.
• Smoking is the leading cause of lung diseases.
• Lung diseases reduce airflow
and oxygen absorption.
– Emphysema destroys
alveoli.
– Asthma constricts
airways.
– Cystic fibrosis produces
sticky mucus.