Studied by 6 people
Active transport
Movement of particles from low to high concentration, requires energy.
Diffusion
Spreading out of particles from high to low concentration, passive process.
Osmosis
Movement of water from high to low concentration through a membrane.
Entry & Exit
Diffusion: Oxygen in, carbon dioxide out.
Osmosis: Water into cells.
Active Transport: Glucose into cells.
Cardiac System
Heart Function:
Deoxygenated Blood: Enters right atrium ➡ right ventricle ➡ lungs.
Oxygenated Blood: Returns to left atrium ➡ left ventricle ➡ body.
🩸 Blood Vessels
Arteries: Thick walls, high pressure, carry blood away from the heart.
Veins: Valves prevent backflow and low pressure, and carry blood to the heart.
Capillaries: Thin walls for exchange, connect arteries and veins.
🧠 Nervous System
Central (CNS): The brain and spinal cord control the body's responses.
Peripheral: Sensory neurons detect stimuli; motor neurons create responses.
🔌 Neurons
Types: Sensory (input), relay (processing), motor (output).
Synapse: Neurotransmitters cross the gap between neurons to continue the impulse.
⚡ Reflex Arc
Stimulus detected by receptors.
Sensory neuron transmits signals to the spinal cord.
Relay neuron processes signal.
The motor neuron sends a signal to an effector (muscle/gland).
The effector produces a response (e.g., moving the hand away from heat).
💡 Endocrine System
Hormone Production: Glands like the pituitary and adrenal release hormones into the blood.
Hormone Function: Hormones like insulin regulate blood sugar; adrenaline prepares the body for stress.
⚖ Negative Feedback
Thyroxine: Regulates metabolism; if levels drop, more is produced until balanced.
Adrenaline: Increases heart rate and glucose; body calms once the stress is gone.
🌡 Homeostasis
Keeps internal conditions optimal for cell function, like temperature and water balance.
🔥 Temperature Regulation
Cold: Shivering generates heat; vasoconstriction reduces heat loss.
Hot: Sweating cools the body; vasodilation increases heat loss.
💧 Water Balance
Kidneys: Filter blood, and regulate water.
ADH: Adjusts water reabsorption in kidneys to maintain balance.
🔄 Menstrual Cycle
FSH: Stimulates egg maturation and oestrogen production.
LH: Triggers ovulation.
Oestrogen: Thickens uterus lining; controls secondary sex traits.
Progesterone: Maintains uterus lining for potential pregnancy.
💊 Contraception
Hormonal Methods: Pills contain oestrogen and progesterone to prevent ovulation and pregnancy.
🩺 Blood Sugar Regulation
Insulin: Lowers blood sugar; produced by the pancreas.
Glucagon: Raises blood sugar; also from the pancreas.
💉 Diabetes
Type 1: No insulin production; treated with insulin injections.
Type 2: Insulin resistance; managed with diet, exercise, and medication.
👁 Eye Functions
Parts: Cornea (focuses light), iris (controls light entry), lens (focuses light), retina (detects light).
Defects:
Short-sightedness: Light focuses in front of the retina; distant objects are blurry.
Long-sightedness: Light focuses behind the retina; close objects are blurry.
Cataracts: Clouding of the lens, obstructing vision.
🧬 Neurone Damage
Permanent: Once damaged, neurons typically don't regenerate, making nervous system injuries severe and hard to treat.
