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. Conclusions
Key Concepts:
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.The lymphatic system has three functions
1. Drainage 2.Absorption 3.Delivery of pathogens
Circulatory, Respiratory, and
Digestive Systems
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
Types of circulatory systems
1. Open circulatory systems
- blood not always in vessels
- insects, spiders
2. Closed circulatory systems
- blood always in vessels
- earthworm, vertebrates
Flow Through an Open
Circulatory System
Grasshopper
Flow Through a Closed
Circulatory System
Earthworm
Closed Circulatory Systems of
Vertebrates
Fish
Amphibian
Closed Circulatory Systems of
Vertebrates
Birds and Mammals
Components of blood
Plasma > 50%
Water 91-92 %
Protein 7-8 %
Ions, sugars, amino acids, hormones,
vitamins, and gases 1-2 %
Cellular portion (Blood Cells) 40-50%
Red blood cells
5.4 million/ul
White blood cells
5,000 - 10,000
Platelets
250,000 - 300,000
The Cellular Components
of Blood
Red Blood Cells
The Cellular Components
of Blood
Components
Relative Amounts
Functions
Plasma Portion (50%–60% of total volume):
1. water
blood
91%–92% of
plasma volume
2. Plasma proteins (albumin, globulins,
Fibrinogens, etc.)
7%–8%
Solvent
Defense, clotting, lipid transport,
roles in extracellular fluid volume, etc.
plasma
3. Ions, sugars, lipids, amino acids,
hormones, vitamins, dissolved gases
1%–2%
Roles in extracellular fluid
volume, pH, etc.
Cellular Portion (40%–50% of total volume):
1. Red blood cells
cells,
platelets
2. White blood cells:
Neutrophils
Lymphocytes
Monocytes (macrophages)
Eosinophils
Basophils
3. Platelets
4,800,000–5,400,000
per microliter
3,000–6,750
1,000–2,700
150–720
100–360
25–90
250,000–300,000
Oxygen, carbon dioxide transport
Phagocytosis during inflammation
Immune responses
Phagocytosis in all defense responses
Defense against parasitic worms
Secrete substances for inflammatory
response and for fat removal from blood
Roles in clotting
Bone Marrow
Aging
Human circulatory system
I.
II.
III.
IV.
V.
VI.
Functions
Blood Vessels
The Heart
Heart Sounds
Blood Pressure
Human Blood types
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 and disease
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
Structure of Blood Vessels
Arteries
Veins
Veins
Veins
Large diameter
Low resistance
Valves
One-way flow
Blood Reservoir
50-60% or total
blood volume
Human circulatory system (The Heart)
1. Two types of chambers
A. Atria (Atrium) – receiving chambers
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
Human pulmonary circuit
2 circuits
Pulmonary
Systemic
Systemic Circuit for Blood Flow
Distribution of
Blood-Heart Output
Heart Structure and Location
The Human Heart
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.
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
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 of human capillaries, only 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
cholesterol
and fat
deposits
narrowed
lumen of
artery
endothelium
lumen of artery
Fig. 39.21, p. 682
Blood Typing
Human Blood types
a single gene located on chromosome 9
(4 types: A, B, AB, O)
Based on markers on red blood cells
[Blood Type]
1.
A (AA, Ao)
2.
B (BB, Bo)
anti B antibodies
anti A antibodies
3.
AB (AB)
none
4.
O (oo)
anti A and anti B antibodies
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)
Lymphatic System
1.
2.
Lymph vessels
and capillaries
Functions
1.
Drainage
2.
Absorption
3.
Delivery of
pathogens
Lymphatic System
Lymphatic System
In Conclusion
1. Circulatory systems consist of a heart, blood
vessels, and blood
2. Blood helps maintain favorable conditions for
cells
3. The human heart is a double pump
4. The heart’s partition separates blood flow into
two circuits, the pulmonary and the other
systemic
In Conclusion
5. Ventricular contraction drives the blood
through both circuits
6. The cardiac conduction system serves as
the basis for the heart’s rhythmic,
spontaneous contractions
7. The lymphatic system has three functions
See you later!