Transcript Cardiovascular NOTES

Comparative Vertebrate
Anatomy and Physiology
Comparative Vertebrate
Anatomy and Physiology
Cardiovascular System
•Heart (4 parts): Sinus
venosus, Atrium, Ventricle,
Conus arteriosus
•Vessels: Arteries, Veins,
Capillaries
The HEART: Where is the
blood going and is it oxygen
rich or poor?
Part 1: Sinus Venosus
•
Thin walls, fibrous tissue, little
muscle
•
Contains Sinoatrial Node =
“Pacemaker”
•
Receives Common Cardinal Veins,
Hepatic Veins and Jugular
•
Passive collector – blood “sucked” in
via aspiration as Sinus Venosus
expands
Part 2, Chamber 1: Atrium
•
Large chamber
•
Thin walls, but muscular
•
Separated from Sinus Venosus by
Sinoatrial Valve
•
Valve opens via blood pressure
•
Relaxed Atrium fills
•
Atrium has the ability to contract
•
Dorsal position allows gravity to
assist contraction in moving blood
Part 3, Chamber 2: Ventricle
•
Thick walls with cardiac muscle
•
Separated from Atrium via
Atrioventricular Valve
•
Valve opens when Atrium
contracts
•
Ventricle fills & produces primary
heart contraction
•
Contraction increases space in
rigid Pericardial Cavity
•
Atrium & Sinus Venosus fill via
aspiration
Part 4: Conus arteriosus (Ventral
aorta)
•
Small diameter tube
•
Thick walls with smooth muscle
•
Flow back into Ventricle prevented
via series of Conal, Semilunar
Valves
•
Serves as auxiliary pump
•
Contracts as Ventricle relaxes
•
Assures steady pressure as blood
enters Ventral Aorta & gills
The VESSELS: Compare and Contrast
• Thick walled
• Capable of contractions
• Oxygen level high, CO2
level low.
• High pressure
• Take blood away from
heart.
The VESSELS: Compare and Contrast
• Thinner walled
• Incapable of
contractions
• Oxygen level low, CO2
level high.
• Low pressure, valves
needed.
• Take blood to heart.
The VESSELS: Compare and Contrast
• VERY thin walled
• Incapable of
contractions
• Oxygen and CO2 level
similar.
• low pressure
• Blood direction both
ways.
The VESSELS: Where is the blood
going and is it oxygen rich or poor?