Download Cardiovascular System

Cardiovascular System
1
EDU2HBS Human Body Systems
2
EDU2HBS Human Body Systems
The Cardiovascular System
A closed system of the heart, blood and blood
vessels
 The heart pumps blood
 Blood vessels allow blood to circulate to all
parts of the body
The function of the cardiovascular system is
3
EDU2HBS Human Body Systems
The Blood (Physical Characteristics)
 Color range
 pH must remain between 7.35–7.45
 Blood temperature is slightly higher than
body temperature
4
EDU2HBS Human Body Systems
Blood Plasma
 Includes many dissolved substances
 Nutrients
 Salts (metal ions)
 Respiratory gases
 Hormones
 Proteins
 Waste products
EDU2HBS Human Body Systems
5
Erythrocytes (Red Blood Cells)
 Outnumber white blood cells 1000:1
 Contain a protein chemical called
hemoglobin
 Make blood bright red
 Contains the element
iron which carries
oxygen
6
EDU2HBS Human Body Systems
Leukocytes (White Blood Cells)
Platelets
 occurs when blood vessels are
ruptured.
7
EDU2HBS Human Body Systems
The Heart
 Location
 Thorax between the
lungs
 Pointed apex
directed toward left
hip
 About the size of your
fist
8
EDU2HBS Human Body Systems
The Heart: Coverings
 Pericardium – a double walled membrane
 Visceral pericardium
 Parietal pericardium
 Serous fluid fills the space between the
layers of pericardium
9
EDU2HBS Human Body Systems
The Heart: Heart Wall
 Three layers
 Epicardium
 Outside layer
 This layer is the parietal pericardium
 Myocardium
 Middle layer
 Endocardium
 Inner layer
10
EDU2HBS Human Body Systems
External Heart Anatomy
11
EDU2HBS Human Body Systems
The Heart: Chambers
 Four chambers
 Atria
 Receiving chambers
 Right atrium
 Left atrium
 Ventricles
 Discharging chambers
 Right ventricle
 Left ventricle
12
EDU2HBS Human Body Systems
Blood Circulation
13
EDU2HBS Human Body Systems
The Heart: Valves
 Four valves
 Atrioventricular valves – between atria and
ventricles
 Mitral valve (left)
 Tricuspid valve (right)
 Semilunar valves between ventricle and artery
 Pulmonary semilunar valve
 Aortic semilunar valve
14
EDU2HBS Human Body Systems
The Heart: Valves
 Valves open as blood is pumped
through
 Close to prevent backflow
15
EDU2HBS Human Body Systems
Coronary Circulation
 The heart has its own nourishing
circulatory system
 Coronary arteries
 Cardiac veins
 Blood empties into the right atrium via the
coronary sinus
EDU2HBS Human Body Systems
16
The Heart: Conduction System
 Intrinsic conduction system
(nodal system)
 Heart muscle cells contract, without nerve
impulses, in a regular, continuous way
17
EDU2HBS Human Body Systems
18
EDU2HBS Human Body Systems
Heart Contractions
 Sequential stimulation occurs at other
autorhythmic cells
 AV node
 AV bundle
 Bundle branches
 Purkinje fibres
19
EDU2HBS Human Body Systems
The Heart: Cardiac Output
 Cardiac output (CO)
 CO = (heart rate [HR]) x (stroke volume
[SV])
 Stroke volume
20
EDU2HBS Human Body Systems
The Heart: Regulation of Heart
Rate
 Starling’s law of the heart – the more that
the cardiac muscle is stretched, the
stronger the contraction
 Changing heart rate is the most
common way to change cardiac output
21
EDU2HBS Human Body Systems
The Heart: Regulation of Heart
Rate
Increased heart rate
 Sympathetic nervous system
 Crisis
 Low blood pressure
 Hormones
 Epinephrine
 Thyroxine
 Exercise
 Decreased blood volume
22
EDU2HBS Human Body Systems
The Heart: Regulation of Heart
Rate
Decreased heart rate
 Parasympathetic nervous system
 High blood pressure or blood volume
 Decreased venous return
23
EDU2HBS Human Body Systems
Blood Vessels: The Vascular
System
 Taking blood to the tissues and back
 Arteries
 Arterioles
 Capillaries
 Venules
 Veins
24
EDU2HBS Human Body Systems
Differences Between Blood Vessel
Types
 Walls of arteries are the thickest
 Lumens of veins are larger
 Walls of capillaries are only one cell
layer thick to allow for exchanges
between blood and tissue
25
EDU2HBS Human Body Systems
Movement of Blood Through
Vessels
 Most arterial blood is
pumped by the heart
 Veins use the milking
action of muscles to
help move blood
Figure 11.9
26
EDU2HBS Human Body Systems
Capillary Beds
 Capillary beds
consist of two
types of vessels
1. Vascular shunt –
directly connects an
arteriole to a venule
27
EDU2HBS Human Body Systems
Capillary Beds
2. True capillaries –
exchange vessels
 Oxygen and
nutrients cross to
cells
 Carbon dioxide
and metabolic
waste products
cross into blood
Figure 11.10
EDU2HBS Human Body Systems
28
Pulse
 Monitored at
“pressure points”
where pulse is
easily palpated
29
EDU2HBS Human Body Systems
Blood Pressure
 Pressure in blood vessels decreases as the
distance away from the heart increases
30
EDU2HBS Human Body Systems
Blood Pressure: Effects of Factors
 Neural factors
 Autonomic nervous system adjustments
(sympathetic division)
 Renal factors
 Regulation by altering blood volume
 Renin – hormonal control
31
EDU2HBS Human Body Systems
Blood Pressure: Effects of Factors
 Temperature
 Heat has a vasodilation effect
 Cold has a vasoconstricting effect
 Chemicals
 Various substances can cause increases or
decreases
 Diet
32
EDU2HBS Human Body Systems
Factors Determining Blood Pressure
33
EDU2HBS Human Body Systems
Variations in Blood Pressure
 Human normal range is variable
 Normal
 140–110 mm Hg systolic
 80–75 mm Hg diastolic
 Hypotension
 Low systolic (below 110 mm HG)
 Often associated with illness
 Hypertension
 High systolic (above 140 mm HG)
 Can be dangerous if it is chronic
EDU2HBS Human Body Systems
34