Transcript Circulatory System and Gas Exchange

By Derek, Eric, and Zack
Evolution of the Circulatory System
and gas exchange: early organisms
 No circulatory system
 Gas exchange through direct diffusion of gases with the
environment
 Gastro Vascular Cavity
 increase surface area
Phylum:
 Protists
 Porifera
 Cnidarians
 Ctenophores
 Platyhelminthes
Open circulatory system
Phylum:
 Arthropods
 Mollusks (except Cephalopods)
 Organs bathed in intercellular fluid rather than
surrounded by vessels.
 Heart used to create a current
 Gas exchange through gills or air sacs
Echinoderms
Specialized circulatory system
 Water vascular system (opened or closed)
 Aids in the transport of food, gases, and waste
 Papulli : gills aiding in gas exchange
Closed circulatory System
 Blood inside vessels
 A chambered heart pumps blood throughout the body
 Usually well developed organs for circulation and gas
exchange
Phylum:
Annelids
Mollusks (Cephalopods)
Chordates
 Fish (2 chambered)
 Reptiles(3 chambered)
 Mammals and birds(4 chambers)
Humans Circulatory system and gas
Exchange Overview
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Four chambered heart
Double circulation
Blood vessels
Blood pressure
Blood
Lymphatic system
Lungs (alveoli, diaphragm, trachea)
Interdependence of circulatory system and gas
exchange
 Homeostasis
 Diseases
Human Heart
 4 chambers (2 atria and 2 ventricles)
 Cardiac muscle tissue
Function:
To pump blood around the body in vessels
Important parts:
 Sinoatrial node (pacemaker)
 Atrioventricular node
 Atruim (blood entering)
 Ventricle (blood exiting)
 Apex
 Septum
Double Circulation
Definition:
 Blood passes through the heart
twice before completing a cycle
around the body
Advantages:
 Maintain velocity of blood
 Increased blood pressure to
organs
 One heart makes coordination
easy
Blood vessels
 Transport blood around the body and contain it in a
permeable wall (endothelium)
Types:
 Veins
 Arteries
 Capillaries
 Veins and arteries also have
smooth muscles and connective
tissues surrounding the vessel
(main purpose is to maintain
blood pressure)
Blood Pressure
Fluids flow from high to low pressures and by
contracting, the heart becomes the high forcing the
blood away from the heart
 Aids in the support of the human body
 Aids in the delivery and return of blood back to the
heart
 Blood pressure also caused by
the contraction of smooth
muscles and other nearby
muscles
Blood
Plasma (55%): water mixed with ions, proteins,
hormones, waste products, and cells
Cell types (45%):
 Erythrocytes (RBC)
 Leukocyte (WBC)
 Platelets
Hemoglobin bind O2 and
transports it to cells. It
also transfers CO2
Lymphatic system
 Due to high pressures in the vessels, blood leaks
constantly from capillaries. Most of the blood is
reabsorbed through osmotic pressure. The rest is
collected by the lymphatic system
 The lymphatic system then directs the absorbed fluid,
now lymph, to the heart where it reenters the
circulatory system
Lungs and the respiratory system
Function: bring gas from the outside and aid in the exchange
of gases from the environment with the ones produced by
the body
Parts:
 Alveoli – increases surface area for gas exchange
 Diaphragm – muscle used for pulling in air
 Trachea – tube that leads air to and from the lungs
Other functions:
 Alter pH of blood through altering levels of CO2 in blood
 Filter out small clots and air bubbles in blood vessels
Interdependence of circulatory
system and respiratory system
 With out the circulation system, none of the cells
inside the organism will get any oxygen and will die.
By supplying them with and taking away gases, other
cells can go about their functions that will overall help
the body, either it be muscle cells for capturing and
eating food, neurons used in thinking about science,
or any of the other many tissue types in the human
body, each with a specialized task.
Homeostasis
 The main purpose of the circulatory and respiratory
system in to bring high levels of oxygen and other
nutrients to cells that can not get it on their own while
taking away waste products and gases that would be
harmful if the concentrations increased
 By constantly moving blood through the body, cells
can live happily and specialized with their needs being
met and their garbage taken away.
 Analogy: the circulatory system is like servants who
bring food and take away the leftovers for their lazy
overlords
Diseases
 Rheumatic Fever
 Caused by a fever, a damaged heart valve at birth can
become damaged further
 Heart attack/Stroke
 the blockage of a vein or artery from something, usually
plaque or platelets, in the heart or the brain respectively
 Anemia
Deficiency of hemoglobin in Red Blood Cells (RBC) or the
deficiency of RBC
 Tuberculosis
 Infection of Mycobacterium tuberculosis that leads to
increase mucus creation in trachea