Exchange And Transport In Animals Flashcards
What is blood made up of?
- Plasma (55%)
- White blood cells (<1%)
- Platelets (<1%)
- Red blood cells (45%)
What is plasma?
- The liquid part of blood
- Carries blood cells through blood vessels
- Contains many dissolved substances like carbon dioxide and glucose
What are platelets?
- Fragments of larger cells
- Cause blood clots when a blood vessel has been damaged
- These clots then block wounds and prevent pathogens getting into the blood
NO NUCLEUS
What are two types of white blood cells?
- Phagocytes, flow around pathogens (ingest) and destroy them
- Lymphocytes, produce chemical antibodies which attach to pathogens and destroy them
How are red blood cells adapted to their function?
- Contain the protein haemoglobin which can combine reversibly with oxygen
- No nucleus so more space for haemoglobin
- Small and flexible to can fit through narrow capillaries
- Biconcave shape to maximise surface area for oxygen absorption
- Thin so short distance for oxygen to diffuse through to reach centre of cell
What are the features of an artery?
- Carry blood away from the heart
- Carry oxygenated blood except for the pulmonary artery - Carry blood under high pressure
- Have thick muscular and elastic walls to pump and accommodate blood
- Connective tissue provides strength
- The lumen is narrow
What are the features of a vein?
- Carry blood to the heart
- Carry deoxygenated blood except for the pulmonary vein
- Carry blood under low or negative pressure
- Thin walls, less muscular tissue than arteries
- Less connective tissues than arteries
- Wide lumen
How is a capillary adapted to its function?
Walls are one 1 cell thick, this allows the exchange of molecules between the blood and the body’s cells, molecules can diffuse across this wall
What substances diffuse into cells from capillaries?
- Oxygen, through the capillary wall and into the tissue fluid then the cells
- Glucose, from the blood plasma across the capillary wall and into tissue fluid then the cells
What substances diffuse out of cells into capillaries?
- Carbon dioxide, from cells into the tissue fluid and across capillary walls into blood plasma
- Urea, from liver cells to tissue fluid then across capillary walls into blood plasma
What is the equation for aerobic respiration?
Glucose + Oxygen =
Carbon dioxide + Water (and releases energy)
What are the uses of energy from respiration in animals?
- Metabolic processes, to build larger molecules from smaller ones (e.g. proteins from amino acids)
- To enable muscle contraction
- To maintain steady body temperature of birds and mammals in colder surroundings
- For cell division
- To move molecules against concentration gradients in active transport
- For the transmission of nerve impulses
What is energy from respiration used for in plants?
- To build larger molecules from smaller ones
What is anaerobic respiration?
The incomplete breakdown of glucose to release energy
What is the advantage of anaerobic respiration?
- Releases energy for muscle contraction when the heart abs lungs can’t deliver oxygen fast enough for aerobic
What are the disadvantages of anaerobic respiration?
- Releases much less energy from each glucose molecule than aerobic
- Lactic acid is built up in muscle and blood and must then be broken down after exercise
What is produced during anaerobic respiration in plants and some fungi?
- Ethanol and Carbon dioxide
- This reaction is also called fermentation
Where does anaerobic respiration take place in cells?
Cytoplasm
What is the formula for cardiac output?
Cardiac output =
Stroke volume x Heart rate
Where does aerobic respiration take place?
Mitochondria