What are the two challenges?
- Deliver O2 to mitochondria for ATP production
- Return CO2 and remove from organism
ventilation?
Ventilation → Diffusion is in the respiratory system
Diffusion?
Diffusion → Circulation is in the circulatory system
Ventilation in the ____ → Diffusion of air or water into ____ in the blood → Diffusion to the ____ resulting in ______
environment
circulation
mitochondria
cellular respiration
Circulatory Systems 3 of them
No circulatory system
Open circulatory system
Closed circulatory system
No circulatory system and example:
- simple invertebrates - diffusion only and passive movement
ex: marine invertebrates: sponges etc.
Open circulatory system and name advantage and disadvantage
- Most invertebrates - Hemolymph because all liquid is mixed
- Advantages: don”t have to have vessels that goes to every single organ
- Disadvantage: less effective if you had a dedicated system. More mixing of fluids that happen
-Closed circulatory system:
- vertebrates
What does the open circulatory system assure?
- assures constant motion and directional distribution
- but is essentially one open cavity
The closed circulatory system process
- heart pumps blood through closed tubular vessel
- branches and becomes thinner
- capillaries allow gas exchange
- Blood from heart is transported by arteries, blood is returned to heart by veins
The fish circulatory system has:
1 circuit and 2 chambers
The closed circulatory system has ___ separate systems… IN FISH BTW
The heart has 2 what? And name the parts and how blood moves around
- Has two separate systems
- Exhcange with tissues
- exchange with environment (respiartory surface: gills or lung)
- Heart has 2 chambers
- Atrium - blood enters here in the heart
- Ventricle - contracts and pushes blood towards the gill. Oxygen is taken up in the gills
Vertebrate circulatory system has evolved:
Amphibians/turtles, snakes, lizards: 2 circuits 3-chambered heart
Crocodiles and birds: 2 circuits and 4-chambered heart
Mammals: 2 circuits and 4-chambered heart but ventricle divided
Mammals: 2 circuits are…
Pulmonary circuit:
- Blood enters right atrium on return from body
- Blood enters right ventricle
- Blood is pumped to lungs from right ventricle
Systemic circuit:
- Blood returns to left atrium from lungs
- Blood enters left ventricle
- Blood is pumped to body from left ventricle
Partial pressure of oxygen and carbon dioxide 9 steps…
- Inhaled air
- Alveolar space (in lungs)
- Blood leaving alveolar capillaries
- Blood entering tissue capillaries
- Tissues
- Blood leaving tissue capillaries
- Blood entering alveolar capillaries
- Alveolar space (in lungs)
- Exhaled air
What has to be synchronized?
- The contraction of the different chambers must be synchronized. Locally regulated; modulated by chemical signals
How is it synchronized?
- contraction is initiated in pacemaker cells
- located in the sinoatrial node (SA node)
- signal spreads along the muscle via gap junctions
Steps of the signals through the heart
- Signal originates at SA node
- Signal spreads over atria; atria contract
- Signal is delayed at AV node
- Signal spreads
- Ventricles relax
How can we measure this the spread of the electrical signal?
- Electrocardiogram (ECG)
Cardiac Cycle?
Ventricular diastole
Ventricular systole
Ventricle Systole
-Both ventricles contract simultaneously
Ventricle diastole:
- Both ventricles relax simultaneously:
