Transport in Animals Flashcards
What does the Right Atrium do generally?
Receives DEOXYGENATED BLOOD from body tissues
What does the Right Ventricle do generally?
Pumps blood to the lungs in the Pulmonary Circuit
What does the Left Atrium do generally?
Receives OXYGENATED BLOOD from the lungs
What does the Left Ventricle of generally?
- Pumps blood to the body tissues in the SYSTEMATIC CIRCUIT
- Has thicker muscular walls than the right ventricle therefore greater pressure
What is the Septum?
The muscular wall that separates the ventricles from each other
What do the Tricuspid and bicuspid valves do?
Prevent the blood from flowing from the ventricles back into the atria
What do the Semilunar valves do?
Prevents high pressure blood from flowing from the arteries back into the ventricles
What is Cardiac muscle made of and what does it contain?
Branching fibres made from MYOFIBRIL TISSUE
Many Mitochondria to provide energy for contraction
What does each cardiac muscle cell contain?
Contractile units called SARCOMERES
Describe how and why muscle cells are separated
By interpolated discs to synchronise contractions
What do Coronary Arteries do?
Deliver nutrients and oxygen to the heart
What can happen if the Coronary Arteries are restricted?
Then the person can suffer a heart attack
Name the 3 stages of the Cardiac cycle
- Diastole
- Atrial Systole
- Ventricular Systole
What is the heart like during Diastole?
The Atria and Ventricles are relaxed
What is the heart like during Atrial Systole?
The Atria contract, Ventricles in systole
What is the heart like during Ventricular Systole?
The Ventricles contract, Atria in diastole
What happens in the Atrioventricular valves during the cardiac cycle?
- Blood in Atria pushes VALVES OPEN after ventricular systole
- BLOOD entering the heart flows through ATRIA INTO VENTRICLES (Diastole)
- Pressure in Atria and Ventricles rises
- Atria contract keeping the valves open
- After atria systole pressure in ventricles is higher than atria and the blood forces the valves closed
- Ventricles contract and tendinous cords prevent the valves from turning inside out
What happens in the Semilunar valves during the cardiac cycle?
- Before Ventricular systole, the pressure in the arteries is higher than in the ventricles, and the Semilunar valves are shut
- VENTRICULAR SYSTOLE quickly raises blood pressure and opens the valves
- Blood spurts out into the arteries at high pressure
- Once in DIASTOLE, Elastic Tissue in the heart helps the Ventricles Recoil and the Cardiac Muscles stretch out again
- The HIGHER PRESSURE in the Arteries causes the Semilunar Valves to CLOSE and again Tendinous Cords prevent the valves from turning inside out
What happens to Ventricular pressure throughout the cardiac cycle?
Diastole = LOW
Atrial Systole = Small bump/rise
Ventricular Systole = Huge increase in pressure
What happens to Atrial Pressure during the cardiac cycle?
Diastole = LOW
Atrial Systole = Small rise/bump
Ventricular Systole = tiny rise at beginning, rises very slowly
What happens in the Blood Vessels during the Cardiac Cycle?
- ARTERY WALLS are ELASTIC and SMOOTH the FLUCTUATIONS in pressure caused by the heart
- Elastic tissue also serves to MAINTAIN the PRESSURE as blood travels throughout the body
- The further along arteries the blood flows the lower the pressure becomes and the more dampened the fluctuations in pressure become
Describe the change in pressure as blood is pumped around the body, through what?
Aorta –>Arteries –>Arterioles –> Capillaries –> Venules –> Veins
As blood travels further along the cycle, pressure, and pressure fluctuations decrease.
Cardiac muscle is Myogenic, what does this mean?
It means it can contract on its own, without needing nerve impulses