Download Animals: Circulation

Animals: Circulation
Blood is the transport medium of
the circulatory system
Outline
1. Key Concepts
2. Circulatory system basics
3. Types of circulatory systems
4. Components of blood
5. Human circulatory system
6. Lymphatic system
7. Key terms
8. Conclusions
Key Concepts:
How important is your circulatory system?
50% of all deaths in this country: heart disease; heart
attack; diabetes; etc.
1. All cells survive by exchanging substances with their
surroundings
2. Blood is the transport medium of the circulatory system
3. There are two types of circulatory systems (open and
closed)
4. A four-chambered heart pumps blood through the body
of birds and mammals
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Key Concepts:
5. The circulatory circuits are the pulmonary and
systemic circuits
6. Arteries transport blood from the heart whereas
veins transport blood to the heart
7. Arterioles control blood-flow through each organ
8. Capillaries are the vessels where diffusion takes place
9. The lymphatic system has three functions
1. Drainage 2.Absorption 3.Delivery of pathogens
Types of circulatory systems
1. No circulatory system (gastrovascular
cavities)
- gastrovascular cavity functions in
digestion and distribution of nutrients
- cnidarians, planarians
2. Open circulatory systems
- blood not always in vessels
(hemolymph = blood + interstitial fluid)
- insects, spiders, mollusks
3. Closed circulatory systems
- blood always in vessels
- earthworm, squids, octopuses, and vertebrates
Gastrovascular
Cavities
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Flow Through an Open
Circulatory System
Grasshopper
Flow Through a Closed
Circulatory System
Earthworm
circulatory system
basics
1. A fluid-blood: as a medium of
transport
2. A system of channels – blood
vessels: conduct the blood
throughout the body
3. A pump – the heart: keep the blood
circulation
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Closed Circulatory Systems of
Vertebrates
Fish – 1. O2 rich blood to tissue
directly
2. O2 poor blood to
the heart 3. pass two beds
Amphibian – 1. mixed blood
pumped to body tissue 2. two
atria and one ventricle
Closed Circulatory Systems of
Vertebrates
Birds and Mammals
Components of blood
Plasma > 50%
Water 91-92 %
Proteins 7-8 %
Ions, sugars, amino acids, hormones,
vitamins, and gases 1-2 %
Cellular portion (Blood Cells) 40-50%
Red blood cells (99% of this cellular portion)
5.4 million/ul
White blood cells
5,000 - 10,000
Platelets
250,000 - 400,000
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Bone Marrow
Aging
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Platelets
a. cellular fragments
b. function in clotting
STIMULUS: tissue damage
muscle spasm,
platelet plug formation
CLOTTING MECHANISM
reactors produce
prothrombin
activator substance
prothrombin converted
to thrombin
thrombin acts
enzymatically on
fibrinogen
fibrinogen forms
threads of fibrin
fibrin forms net at
damaged site, entangling
blood cells, platelets
clot formation
Human circulatory system
Functions
II. Blood Vessels
III. The Heart
IV. Heart Sounds
V. Blood Pressure
I.
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Human circulatory
system
Human circulatory system
Functions
1. Transport of O2 and CO2
2. Distribution of nutrients
3. Transport of waste ( liver kidney excretion)
4. Distribution of hormones
5. Regulation of body temperature
6. Protection of the body against
blood loss
7. Protection of the body against diseases
Human circulatory system (Blood
Vessels)
Arteries and Arterioles
a. Thick walls, smooth muscle with elastic tissue to withstand
high pressure
b. Carry blood away from the heart
Capillaries
a. Tiniest vessels; thin, single-cell thick for easy diffusion
b. Exchange of materials between blood and body cells
Venules and Veins
a. One-way valves in thin-walled vessels surrounded by thin
layer of smooth muscle giving low resistance to blood flow,
which is assisted by skeletal muscle
b. Returns blood to the heart
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Blood Vessels
Arteries/arterioles:
Thick walls, smooth
muscles - elastic
Capillaries:
Tiny: thin single cell
Endothelium
(epithelium)
Veins/veinules: Thin
Walls, thin smooth
muscle; one-way
valves
Structure of Blood Vessels
Veins
Veins
Large diameter
Low resistance
Valves
One-way flow
Blood Reservoir
50-60% or total
blood volume
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Human circulatory system (The
Heart)
1. Two types of chambers
A. Atrium – a receiving chamber
B. Ventricles – pumping chambers arteries
2. Mammals and birds
– 2 halves of heart (separated)
- each half = atrium + ventricle
One circuit (pulmonary circuit) –pick up O2
R V lungs L A L V
2nd circuit (Systemic circuit) – deliver nutrients, O2,
etc.
L V body tissue R A R V
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Human pulmonary circuit
2 circuits
Pulmonary
Systemic
Systemic Circuit for Blood Flow
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Distribution of
BloodBlood-Heart Output
Heart Structure and Location
Human circulatory system (The
Heart)
Pacemaker – a region of cells that generate
electrical signals, heart contracts.
= Sinoatrial node (SA node)
SA node sends signal to walls of atria (to
contract) it also sends signal to another
node AV node (atrioventricular node).
Then AV node sends signal to ventricle
muscles ventricles contract.
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Cardiac Conducting System
SA node
Pacemaker
AV node
AV bundle
Human circulatory system(Heart
Sounds)
Cardiac output = 5-6 l /min (sports 30-35 l / min)
60-80 contraction/min
First sound “Lubb” = closing of valves between
atria and ventricles.
Second sound “Dubb” = closing of valves between
ventricles and arteries.
Systole = period of contraction of heart ventricles,
begins with “Lubb’ sound.
Diastole = period of relaxation of heart ventricles,
begins with “Dubb” sound.
Cardiac Cycle
Systole
Diastole
Closure/Opening
of valves
Contraction of
ventricles is the
force for blood flow
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Human circulatory system(B.P.)
Pressure = force/unit area
Blood pressure (B. P.) = pressure of blood on walls
of vessels.
Young adult: Systolic B. P. ≈ 120 mmHg
Young adult: Diastolic B. P. ≈ 80 mmHg
(millimeters of mercury)
50,000 miles (100,000 km) of human capillaries,
less than 30-50% capillaries open. No closure
of capillaries to brain & heart.
wt. in kg x 8% = # l blood, 1 lb = 0.45 kg
165 lb = 75 kg x 8% = 6 l blood
Blood Pressure
Systolic
Diastolic
Blood Pressure
Systolic
Diastolic
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cholesterol
and fat
deposits
narrowed
lumen of
artery
endothelium
lumen of artery
Lymphatic System
Lymphatic System - supplement to vertebrate circulatory system.
It runs parallel to venous half of circulatory system.
1. Structure
a. complex network of thin-walled vessels and two
organs (thymus and spleen both produce
lymphocytes)
b. in proximity to the capillary network
c. composed of cells with openings between them that
act as one-way valves
2. Components of lymphatic fluid (lymph):
a. water b. white blood cells c. foreign matter
Lymphatic System
3. Lymph flow comes from the contraction of nearby
muscles (walking, breathing, etc.)
4. Functions
a. Remove of excess body tissue fluids
b. Transport of fats from the small intestine to
blood (absorption)
c. Defense of the body by exposing viruses,
bacteria, and cancer cells to white blood cells
(sites = lymphatic nodes)
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Lymphatic System
1.
2.
Lymph vessels
and capillaries
Functions
1. Drainage
2. Absorption
3. Delivery of
pathogens
Lymphatic System
Lymphatic System
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Open circulatory system
Closed circulatory system
Cardiovascular system
Atrium
Ventricles
Arteries
Arterioles
Capillaries
Venules
Veins
Systemic circuit
Double circulation
Pulmonary circuit
Hemolymph
Gastrovascular cavity
Systole
Diastole
Sinoatrial node
Pacemaker
Atroventricular node
Blood pressure
Lymphatic system
Lymph nodes
Red blood cells (Erythrocytes)
Hemoglobin
White blood cells (Leukocytes)
Platelets
In Conclusion
Circulatory
systems consist of a heart, vessels,
and blood
Blood
consists of plasma, red and white blood
cells, and platelets
Blood
delivers oxygen, and other products as
well as transports waste products from cells
The
human heart is a double pump
The
two circuits pumped from the heart are the
pulmonary and systemic circuits
In Conclusion
The pulmonary circuit allows blood to pick up
oxygen and get rid of carbon dioxide
The systemic circuit allows blood to deliver oxygen to
cells and pick up waste products
Ventricular contraction drives the blood through
both circuits
Blood flows from high pressure areas to low pressure
ones
Capillary beds are diffusion zones
Veins bring blood back toward the heart
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In Conclusion
The heart’s conducting system regulates the
heart beat and rhythmic contraction of the
heart
The
SA node initiates the action potentials
and is the pacemaker
The
lymphatic system takes up fluids from the
blood, transports fats, and delivers pathogens
to nodes
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