Paper 3 Cram Flashcards
How does gas exchange occur in fish?
Ventilation begins with the fish opening its mouth followed by lowering the floor of buccal cavity, thus enabling water to flow into it. Afterwards, fish closes its mouth, causing the buccal cavity floor to raise, thus increasing the pressure. The water is forced over the gill filaments by the difference in pressure between the mouth cavity and opercular cavity. The operculum acts as a valve and pump and lets water out and pumps it in.
Hormones released from the adrenal medulla
The adrenal medulla releases the adrenaline and noradrenaline hormones
Hormones released from the adrenal cortex
The adrenal cortex releases steroid hormones. This includes glucocorticoids, mineralcorticoids and androgens.
Role of glucocorticoids
Glucocorticoids regulates glucose and protein metabolism, as well as supression of the inflammatory response
Role of mineralcorticoids
Mineralcorticoids maintain salt concentrations to control blood pressure.
What’s the difference between coenzymes and cofactors?
Cofactors = inorganic ions that aid enzyme function
Coenzymes = organic ions that are derived from vitamins
Examples of human cells specialised for their functions
→ Erythrocytes → Biconcave shape (increased surface area to volume ratio to transport more oxygen), No nuclei (more space for haemoglobin), flexibility (move through capillaries)
→ Neutrophils → multi-lobed nucleus → fit through gaps to reach sites of infection
→ Sperm → flagella for movement, lots of mitochondria for ATP supply
→ Squamous epithelium → flat for increased diffusion
→ Cilliated epithelium → contains goblet cells which release mucus that traps pathogens
→ Cartilage (connective tissue) → prevents ends of bones rubbing and causing damage
Plant cell examples that are adapted to their functions
→ Palisade cells in plants → thin walls for diffusion and large vacuoles to maintain turgor pressure
→ Root hair cells → root hairs increases surface area to increase water uptake through the roots of the plant
→ Guard cells in stomata → can change shape to prevent excessive water loss, has a thicker cell wall one side to prevent symmetrical shape change
→ Epidermis → found on plant surface and contains the stomata, contains waxy cuticle which helps prevent excessive water loss in plants
→ Xylem → contatains lignin for strength
→ Phloem → transports sucrose via mass flow
What is tidal volume?
Tidal volume = maximum volume of air in a normal resting rbeath
How to calculate pulmonary ventilation rate?
Pulmonary ventilation rate = tidal volume x breathing rate
What are the different structures found within the liver and their functions?
→ Hepatocytes = main liver cell which divide and replicate
→ Sinusoids = spaces between hepatocytes where blood from hepatic artery and portal vein mixes
→ Kupfer cells = macrophages
→ Canaliculi = spaces where bile is secreted and then drained into ductules
→ Hepatic artery = Supplies the liver with oxygenated blood
→ Hepatic portal vein = supplies blood rich in products for metabolism
→ Hepatic vein = supplies the liver with deoxygenated blood
→ Bile duct = transports bile to gall bladder
→ Gall bladder = bile is stored then released into small intestine
→ Ligaments seperates liver lobes
What are the primary non-specific animal defences against pathogens?
→ Skin (secretes sebum that inhibits pathogen growth)
→ Mucous from globet cells
→ Lysosomes in tears and urine
→ Stomach acid
→ Blood clotting (platelets clump at broken vessel and adhere, thrombrin + fibrin released that helps clot)
→ Fever
→ Inflammatory response
→ Phagocytosis
What is the action of the inflammatory response?
Inflammatory response:
→ Inflammation localised and results in pain, swelling and redness
→ Histamines released which causes vasolidation → temperature increase, plasma forced out (swelling)
→ Cytokines attract phagocytes
What are baroreceptors?
Baroreceptors are pressure receptors. They are sensitive to blood pressure. Too high = impulses sent to medulla oblongata centre which decreases HR (impulses sent along parasympathetic neurones to SAN) and vice versa.
What are chemoreceptors?
Chemoreceptors detect changes in chemical levels. They are sensitive to pH level of blood (CO2 increase = pH decrease due to carbonic acid) → heart rate increased to increase blood flow