Chapter 20
Circulation
and Respiration
What Are the Major Features and Functions of
Circulatory Systems?
Features:
Fluid (blood) =
transport medium
Blood vessels =
channels
Heart = pump
Function
Transport
(primary function)
Regulates
temperature
Circulates white
cells (immunity)
What Are the Major Features and Functions of
Circulatory Systems?
Animals Have Two
Types of Circulatory Systems: Open and closed
What Are the Major Features and Functions of
Circulatory Systems?
The Vertebrate
Circulatory System Transports Many Substances
Oxygen
Carbon dioxide
Nutrients
Waste Products
Hormones
Also important in
temperature control, pH regulation
How Does the Vertebrate Heart Work?
The Vertebrate
Heart Consists of Muscular Chambers
Atria (atrium)
collect blood
Ventricles Pump
The number of chambers differs among
vertebrate classes
The evolution of the vertebrate heart
Evolution of the Vertebrate Heart
Increasing number
of chambers keeps oxygenated blood (RED) from mixing with deoxygenated blood
(BLUE), improves efficiency.
Vocabulary:
Artery (away from heart) , Vein (toward heart),
capillary
Parts is Parts
Important Veins:
Superior and
inferior vena cava
Pulmonary vein
Important
Arteries
Aorta
Pulmonary artery
Important valves
Atrioventricular
separate atria and ventricles
Semilunar- one
way from heart to arteries
How Does the Vertebrate Heart Work?
The Atria and
Ventricles Contract in a Coordinated Cycle: the Cardiac Cycle
First atria, then
ventricles, contract and relax.
Challenges:
Maintain one way
flow
Contract all at
once
The Atria and Ventricles Contract in a
Coordinated Cycle
Electrical Impulses Coordinate the Sequence of Contractions
The SA node
serves as the hearts pacemaker
Its signal to contract
spreads through the muscle fibers of both atria to the AV node.
The AV node then transmits the signal through
bundles of excitable fibers that stimulate the ventricular muscles to contract.
How Does the Vertebrate Heart Work?
The Hearts Contractions
Result from Movement of Filaments in Muscle Cells
Muscle contraction
How Does the Vertebrate Heart Work?
Injury and
Disease Can Impair Heart Function
Fibrillation-
pacemaker fails
Bacterial
infection of valves
Damage muscles
heart attack
What Is Blood?
Plasma Is
Primarily Water and Dissolved Substances
Red Blood Cells
Carry Oxygen from the Lungs to the Tissues
White Blood Cells
Help Defend the
Body against Disease
Platelets Are
Cell Fragments That Aid in Blood Clotting
What Are the Types and Functions of Blood Vessels?
Arteries and
Arterioles Carry Blood away from the Heart
Capillaries Are
Microscopic Vessels through Which Nutrients and Wastes Are Exchanged
Venules and Veins
Carry Blood Back to the Heart
The human circulatory system
How Does the Lymphatic System Work with the
Circulatory System?
The Lymphatic
System Returns Fluids to the Blood
The Lymphatic
System Helps Defend the Body against Disease
The Lymphatic
System Transports Fats
from the Small Intestine to the Blood
How Are Oxygen and Carbon Dioxide Exchanged in Animal
Bodies?
Fish: Gills
Terrestrial
Animals Have Internal Respiratory Structures
How Does the Human Respiratory System Work?
Gas Exchange
Occurs Between Alveoli and Capillaries
Alveoli and
capillary walls are
only one cell thick,
very close to one another,
have cells coated in a thin layer of fluid.
This arrangement allows gases to dissolve and
diffuse easily between the lungs and the circulatory system.
How Does the Human Respiratory System Work?
The Lungs Are
Protected by an Airtight Cavity
Air Is Inhaled
Actively and Exhaled Passively
How Does the Human Respiratory System Work?
Human respiration
rate is controlled by a part of the brain called the medulla.
It sends signals
to the body to adjust the breathing speed to provide enough oxygen for every
activity sleeping, eating, exercising, etc.
The level of
carbon dioxide, not oxygen, in the blood is measured by the brain, which in
turn makes needed adjustments in the respiration rate.
Smoking causes cancer
Smoking causes emphysema
American Smokeout Day
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