Animal coordination, control and homeostasis

• Insulin

  Hormone that acts when blood glucose levels are high, converts glucose into glycogen, lowering blood glucose levels.
• Glucagon

  Hormone that acts when blood glucose levels are low, converts glycogen into glucose to raise blood glucose levels.
• Glycogen

  Stored in the liver and muscle cells, a polysaccharide made of many glucose units produced due to the action of insulin.
• Pancreas

  Organ that detects blood glucose levels and produces and secretes insulin or glucagon into the blood.
• Negative Feedback

  Mechanism that reverses a change, for example, bringing blood glucose level back to a set concentration.
• Liver

  Organ where glycogen is stored when blood glucose levels are high.
• Vasodilation

  When smooth muscle in arteries and arterioles relaxes, widening the lumen increases blood flow into capillary loop, so more heat loss occurs from skin surface.
• Vasoconstriction

  When smooth muscle in arteries and arterioles contracts, narrowing the lumen reduces blood flow into the capillary loop, which reduces heat loss from the skin surface.
• Thermoregulation

  Maintenance of a constant internal temperature within a narrow range despite external changes in humans (approximately 37°C).
• Homeostasis

  Maintenance of a constant internal environment despite external changes, including blood glucose control, temperature, and water content.
• Dermis

  Tissue that contains sweat glands, capillary loops, and hair follicles that are involved in thermoregulation.
• Epidermis

  Outer tissue of the skin that contains sweat pores, involved in thermoregulation.
• BMI (Body Mass Index)

  Formula where mass in kilograms is divided by height squared in meters, used to determine if someone is underweight, normal weight, or overweight.
• Endocrine Gland

  Gland that produces hormones that are secreted into the blood.
• Shunt Vessel

  Blood vessel that links an artery to a vein, allowing blood to bypass capillaries.
• Erector Pili Muscle

  On contracting, this raises the hair follicle; on relaxing, the hair follicle is lowered.
• Hypothalamus

  Thermoregulatory system in the brain that helps control temperature and other homeostatic processes.
• Adrenaline

  Hormone made in adrenal glands involved in fight or flight response.
• Assisted Reproductive Therapy (ART)

  Fertility treatments to increase the likelihood of becoming pregnant, e.g., clomiphene therapy or IVF.
• Clomiphene

  Fertility drug causing more FSH and LH to be released, stimulating ovum maturation and ovulation.
• Hormonal Contraception

  Hormone-based contraception to prevent the release of ova. Contains oestrogen and sometimes progesterone. Can be in the form of injections, patches, or tablets. Does not prevent STI transmission
• Barrier Contraception

  Barrier between the sperm and the ova used to reduce the chance of becoming pregnant and prevent STI transmission (e.g., condoms).
• Corpus Luteum

  Leftover ovarian follicle following ovulation; produces progesterone.
• Follicle Stimulating Hormone (FSH)

  Hormone produced by the pituitary gland; matures ova in the ovarian follicle and stimulates the release of oestrogen.
• In-vitro Fertilization (IVF)

  Fertilization of an ovum with sperm outside of the body, which is then implanted in the uterus. An example of ART.
• Luteinizing Hormone (LH)

  Hormone produced by the pituitary gland; causes ovulation, typically on day 14 of the menstrual cycle.
• Menstruation

  Breakdown and release of the uterine lining at the start of the menstrual cycle due to low progesterone.
• Negative Feedback

  Mechanism that reverses a change, for example, when the body detects that the level of a substance (e.g., a hormone) has gone above or below the normal level, a response is triggered to reverse the change and bring it back to normal.
• Ovarian Follicle

  A small fluid-filled sac that contains an immature ovum, found in the ovaries.
• Ovulation

  Release of an ovum from the ovarian follicle into the fallopian tube on approximately day 14 due to a peak in LH.
• Progesterone

  Hormone produced by the corpus luteum; maintains the thick uterine lining in case fertilization occurs. High levels inhibit LH and FSH; low levels allow FSH to increase again and start the menstrual cycle.
• Thyroxine

  Hormone produced by the thyroid gland; controls metabolism.
• Thyrotropin Releasing Hormone (TRH)

  Hormone released by the hypothalamus in response to low levels of thyroxine.
• Thyroid Stimulating Hormone (TSH)

  Hormone produced by the pituitary gland; acts on the thyroid gland in response to low levels of thyroxine.
• Excretion

  Removal of metabolic waste from cells.

  Examples: sweat, carbon dioxide, urine.
• Osmoregulation

  Maintenance of water content and mineral ions in the blood despite external changes.

  A form of homeostasis.
• Nephron

  Functional units of the kidney.

  Consists of a glomerulus and tubules where the glomerular filtrate passes before merging as urine.
• Ultrafiltration

  Process that occurs due to high pressure forcing small molecules out of the blood in the glomerulus into the Bowman's capsule.
• Selective Reabsorption

  Process in the nephron where useful molecules are absorbed out of the filtrate back into the blood.
• ADH (Antidiuretic Hormone)

  Hormone produced by the pituitary gland.

  Acts on the collecting duct, making it more permeable so more water is reabsorbed back into the blood.