Transcript Blood pressure - Cedar Crest College

Good Morning!
Welcome to a Lecture on
Internal Transport!
Chapter 42
Power point slides will be available on the course website.
Any Questions? My office is Miller 23, Ext. 3605.
I. Meeting the Metabolic Needs of a
Multicellular Organism
Requires:
• A delivery system for nutrients, minerals, gases
and wastes so cells can exchange with their
environment.
• A closed circuit that minimizes the diffusion
distance.
• Extensive communication with other systems:
Respiratory, Digestive, Urinary and Lymphatic.
• Maintenance of Homeostasis.
II. The Vertebrate Circulatory System
aka Our Cardiovascular System
• Continuous closed circuit under pressure.
• Components: Transporting Medium = Blood
Plumbing = Blood Vessels
Pump = 4 chambered Heart
• 3 functions: Transportation, Protection and Regulation
• The health of this system is vital to all other organ
systems. Cardiovascular disease is the leading cause of
untimely death in the US.
The Closed Circuit
and its Pump
The 4 chambered Mammalian heart
III. The Transporting Medium
Red Gold
5-6 liters in circulation
A Blood Smear
Figure 42.4
Table 42-1
Whole blood
Figure 42-4
55%
Page 811
Plasma
Cell
components
45%
Plasma
proteins
Lipoproteins Albumins Globulins Fibrinogen
Clotting
proteins
Water
Salts
Dissolved
gases
Hormones
Glucose
Wastes
White
blood cells
(leukocytes)
7 µm
Granular
leukocytes
Agranular Red blood cells
leukocytes
1 to 2 µm
Platelets
(erythrocytes)
250 million Hb molecules/RBC
10 to 14 µm
Neutrophil
‘NLMEB’
10 to 14 µm
Eosinophil
10 to 14 µm
Basophil
15 to 20 µm
Monocyte
8 to 10 µm
Lymphocyte
Erythrocytes
Credit: © Dr. Dennis Kunkel/Visuals Unlimited
Credit: © Dr. Richard Kessel & Dr. Randy Kardon/Tissues & Organs/Visuals Unlimited
900019
Red and white blood cells within an arteriole. Arteries branch into arterioles within organs and
deliver blood to the capillaries. SEM X6130.
WBC Phagocytosis
WBC’s leaving circulation
to begin the inflammatory response
1
Injury to
blood vessel
2 Wall of vessel
contracts
Blood flow
3 Platelets adhere
to collagen fibers
of damaged vessel
wall
Blood flow
decreases
Blood flow
decreases
Prothrombin
Damaged cells and platelets
release substances that
activate clotting factors
Prothrombin
activator
Ca2+
Fibrinogen
Thrombin
Ca2+
Fibrin threads (clot)
STOP THE BLEEDING!
Figure 42.5
4 More permanent
clot forms
Platelet
plug
Blood flow
ceases
Credit: © Dr. Richard Kessel & Dr. Randy Kardon/Tissues & Organs/Visuals Unlimited
Blood Clot. Red blood cells are trapped in a clot of fibrin. Damage to the connective tissue in
blood vessels triggers a series of events that leads to the conversion of fibrinogen (an inactive
sealant in our blood) to be converted to fibrin. SEM X4005.
900021
IV. Blood Vessels
3 Types of Blood Vessels
Outer coat
(connective tissue)
Smooth muscle
VEIN
Figure 42.6
Endothelium
ARTERY
Outer coat
(connective tissue)
25 µm
Endothelium
CAPILLARY
Key Points:
•Organization
of the circuit
•Direction
•Pressure (s)
•Oxygen levels
•Exchange
•BP/BV
regulation
Vein
Lymphatic
Artery
Venule
Arteriole
Capillary Bed
Lymph
node
Constriction
Dilation
Figure
42.6
Lymphatic System
involvement
Movement of
interstitial fluid
Lymph
capillaries
Arterial end
of capillary
Figure 42-20
‘Proteins and Pressures’
Page 827
Blood
pressure
(+40)
Osmotic
pressure
of plasma
(- 28)
Osmotic
pressure
of interstitial
fluid
(+3)
(40 + 3) - 28 = +15
Net filtration
Blood
pressure
(+15)
Venous end
of capillary
Osmotic
pressure
of plasma
(- 28)
Osmotic
pressure
of interstitial
fluid
(+3)
(15 + 3) - 28 = - 10
Net absorption
Now tie in the Lymphatic System (again)
Figure 42-19
42.19
Figure
Page 827
Venule
Arteriole
Valve
Red blood cells
Plasma
Connective
tissue fibers
Capillary
bed
Lymph
Plasma
Figure 42.18
Right
lymphatic
duct
Right
subclavian
vein
Thymus
Axillary
lymph
nodes
Lymphatics
of breasts
Superficial
lymphatics
of upper
limb
Superficial
lymphatics
of lower
limb
Tonsil
Cervical
lymph
nodes
Left
subclavian
vein
Thoracic
duct
Spleen
Spider Woman???
No, It’s Lymphatic Woman!
Application
Figure, Page 822
500 µm
500 µm
Atherosclerosis
Normal Artery
Myocardial Infarction, Cerebrovascular Accident
A heart attack waiting to happen
Credit: © Carolina Biological/Visuals Unlimited
V. Behold the Heart
A. Lub Dub provides us with……..
• Circulation of 5-35 liters of blood/minute
• Through at least 60,000 miles of blood
vessels
• 1 heartbeat (lub dub) in 0.8 seconds
• Heartbeats of 100,000 times /day
• 2.5 billion times over our lifetime
• Pumping 300 million liters (80 million
gallons) over our lifetime
• Ever faithful….if we identify risk factors
and modify our lifestyles.
B. Those Risk Factors for the #1
Killer = Cardiovascular Disease
•
•
•
•
•
•
SMOKING
Hypertension
Couch Potato Lifestyle
Poor Diet
Obesity
High cholesterol, Trigylcerides and LDL
levels; Low HDL levels
• Diabetes mellitus
Your heart: Your hardest working muscle of all!
C. Your heart is a Double Pump with a Double Circuit:
•Pulmonary Circulation (blood to lungs for oxygen)
•Systemic Circulation (blood to the body)
Systemic circulation
Figure 42-16
Page 824
Capillary network
Appreciate the Circuitry
Brain
Figure 42.16
Pulmonary
artery
Superior
Pulmonary vena
circulation cava
Carotid
artery
Pulmonary
artery
Right lung
Left
lung
Aorta
LA
RA
RV
Pulmonary
vein
Inferior
vena cava
LV
Pulmonary
vein
To lower parts
of the body
Capillary
network
D. By design: 4 Chambers, Valves and Vessels
Superior vena cava
Aorta
Left pulmonary arteries
Pulmonary artery
Right pulmonary
arteries
Pulmonary veins
Left atrium
Pulmonary valve
Mitral valve
Right atrium
Aortic valve
Pulmonary veins
Chordae tendineae
(“heartstrings”)
Tricuspid valve
Papillary muscles
Right ventricle
Inferior vena cava
Left ventricle
Interventricular septum
Aorta
Figure 42.9
E. Let’s follow a drop of blood through the heart.
Large Veins (Superior, Inferior Vena Cava)
Right Atrium
Valve
Right Ventricle
Valve
Pulmonary Arteries
Lungs
Pulmonary Veins
Left Atrium
Valve
Left Ventricle
Aorta
Credit: © L. Bassett/Visuals Unlimited
Dissection of pericardium and heart in situ, interior of left atrium and left ventricle.
303794
Notice the thicker, stronger walls of the left ventricle
A superior view of the valves
F. And the beat goes on….
Electrical Cells :Slow Sodium,
Figure 42-10a
Fast Calcium
channels
Page 818 Contractile Cells: Fast Sodium,
Intrinsic Conduction
System
Slow Calcium
Channels
SA node or
pacemaker
Left atrium
Right
atrium
AV node
AV bundle
Right
ventricle
Left ventricle
Purkinje
fibers
Right and left
branches
of AV bundle
Figure 42.10
Electrocardiography:
Placing electrodes on the body to monitor the electrical activity of the heart.
Credit: © Mediscan/Visuals Unlimited
3202
And if the pacemaker is broken we can fix it!
G. The Cardiac Cycle
•
•
•
•
Follows the electrical message (Action Potential).
Makes up one complete heartbeat.
Takes. 0.8 seconds.
Involves contraction = SYSTOLE
and relaxation = DIASTOLE of the heart chambers.
• Systole and Diastole are monitored when we have
our Blood Pressure taken (120/70).
• ‘Lub-dub’ heart sounds during the cycle result from
the valves closing.
• Valve problems are diagnosed as heart murmurs.
The CARDIAC CYCLE
Superior
vena cava
Aorta
Pulmonary
artery
Semilunar valves
Figure 42.11
Right atrium
Tricuspid valve
Inferior vena cava
Pulmonary vein
Left atrium
Mitral valve
5 Period of falling
pressure
1 Atrial systole
Right
Left
ventricle ventricle
Heart
sounds
2 Beginning of
ventricular systole
4 Beginning of
ventricular diastole
3 Period of rising
pressure
Figure 42-14
H. Blood Pressure reflect how healthy we are and how hard our heart has to work
Highest in the arteries due to systole
Blood
volume
Blood pressure
=
Blood
viscosity
X
Blood flow
Peripheral
resistance
Systolic Pressure
Diastolic Pressure
115/70
Cardiac
output
Vasoconstriction
The reason why we need to exercise!
(Low pressure in veins.)
Similar to Figure 42-15
on page 823
Increases
Decreases
Stressors and
other stimuli
I. Extrinsic
regulation
From 2 systems:
Hypothalamus
Nervous System
&
Endocrine System
Figure 42-12
Page 820
Cardiac centers
in the medulla
Brain
Increased
venous
return
Adrenal
glands
Epinephrine
and
Norepinephrine
STROKE
VOLUME
Figure 42.12
Sympathetic
Parasympathetic Increase
nerves
nerves
in body
(accelerator nerves)
(vagus)
temperature
Norepinephrine
Acetylcholine
X
HEART
RATE
=
CARDIAC
OUTPUT
(~5 L/min)
A Review For You!
• Pump Your Blood
Just in case you need some words of encouragement today….
Have a wonderful day!