Transport in animals Flashcards
What muscle is the heart made out of?
dark muscle called cardiac muscle
What are the two main pumping chambers?
ventricles and atria
What do coronary arteries do?
supply oxygenated blood to the heart muscles
What happens when arteries restrict blood flow?
due to build up of fatty acids causing angina and a heart attack
What blood vessels are above the heart?
tubular blood vessles
What do tubular blood vessels do?
veins that carry blood into the atria and arteries that carry blood away from the heart
what do tendinous cords do?
prevent the valves from turning inside out when the walls of the ventricles contract
what separates the two sides of the heart and why
septum
ensures deoxygenated blood and oxygenated blood is kept separate
what do semilunar valves do?
semi-lunar valves prevent blood returning to the heart as the ventricles relax
What does the mitochondria between the muscle fibrils do?
supply energy for contraction
What are the mitochondria divided by?
intercalated discs which facilitate synchronised contraction each nucleus is divided into contractive units called sarcomeres
What do valves do?
they stop backflow and ensure blood flows in right direction, they open and close due to changes in the blood pressure
What causes the pulse
the pressure created when the left semilunar valve is closed
Where is the SAN?
at top of the right atrium
What is a sino-atrial node (SAN)
its a small patch of tissue that generates electricity by imitating a wave of excitation at regular intervals - pacemaker
what does a electrocardiogram do?
monitors activity of the heart
What is the need for a transport system
- Size – larger organsims cell is further from its surface the diffusion pathway in increased and the rate reduced and diffusion is too slow to supply all the requirements, outer cells use up the supplies
- Surface area to volume ratio- lager animals have a smaller surface area to volume ratio which means each gram of tissue has a smaller area of body surface for exchange
- Level of metabolic activity – if animal is active it needs a good supply of oxygen for movement and warmth if a mammal
what are the features of a good transport system
- Fluid is transport the stuff
- A pump to create pressure that will push the fluid around the body
- Exchange surfaces that enable substances to enter the blood and leave it again where they are needed
- Tubes or vessels to carry the blood by mass flow
- Two circuits one to pick up oxygen and another to deliver it to the tissues
describe the pathway of a single circulatory system
heart - gills - body - heart
describe the pathway of a double circulatory system
- Double = heart-body-heart-lungs-heart
- Heart-body = systemic
- Heart-lungs=pulmonary
what are the advantages of double circulation and disadvantages of single circulation
- Blood pressure drops as blood flows through tiny capillaries of gills
- Low pressure therefore foes no flow very quickly
- Rate at which gaseous exchange occurs is limited
+ increased pressure therefore it flows more quickly
+ faster and more efficient as it is pumped twice
+ systemic can have a higher pressure then pulmonary so at various parts the pressure can vary - Pressure must not be too high in the pulmonary circulation otherwise it could damage the delicate capillaries in the lungs