What is homeostasis? | The maintenance of optimum conditions within the body, in response to internal or external changes. |
What is a receptor and what does it do? | They detect stimuli and send the information as electrical impulses to the co-ordinator. |
What is a co-ordinator and what does it do? | The CNS (central nervous system), usually being the brain or spinal cord. It receives the information and organises a response, sending it to the effector. |
What is an effector and what does it do? | It produces a response, which is muscles contracting or glands releasing hormones. |
What is negative feedback? | A process that regulates our internal environment. |
What is a reflex action? | A rapid response to a stimulus that doesn't travel to the brain. |
What is a neurone? | A nerve cell. |
What are nerotransmitters? | A chemical that diffuses across the synapse. |
What is the synapse? | The gap between two neurones. |
What is a stimulus? | A change in the external or internal environment. |
What is the spinal cord? | A part of the CNS. It's a co-ordinator. |
What do sensory neurones do? | They carry information from the receptors to the CNS as electrical impulses. |
What do motor neurones do? | They carry information from the CNS to the effectors as electrical impulses. |
What do relay neurones do? | They connect the sensory and motor neurones. |
What is a hormone? | A chemical messenger that travels through the blood. |
What is the endocrine system? | A process that regulates hormones in the blood stream. |
What is the pituitary gland? | It's known as the 'master gland' and it releases growth hormones. |
What does the thyroid gland release? | Thyroxine, it controls metabolism. |
What does the thyrus gland relase? | White blood cells. |
What does the adrenal gland produce and where is it found? | It produces the adrenaline hormone and its next to the kidneys. |
What does the pancreas produce? | Insulin and glucagon. They control blood-glucose levels. |
What glands are involved in the endocrine system? | Pituitary gland, thyrus gland, thyroid gland, adrenal gland, pancreas, ovaries or testes. |
How is the endocrine system different to the nervous system? | It uses chemicals instead of electrical impulses.
The chemicals travel through the bloodstream instead.
It's slower.
it has longer lasting effects.
Its widespread because it travels through the bloodstream. |
What does thyroxine do> | Stimulates the basal metabolic rate, controls the speed of energy release and improves growth + development. |
What does the pituitary gland release to stimulate the release of thyroxine? | TSH (thyroid stimulating hormone). |
Why is adenaline not negative feedback? | It's only released when it's needed and filtered out of the blood to restore resting levels. Negative feedback is a process that all cells constantly undergo. |
What is basal metabolic rate? | The rate at which chemical reactions happen when the body is at rest. |
What is type 1 diabetes? | A diseases where the pancreas doesn't secrete enough insulin. It's due to genetic disorders, autoimmune coniditions, and is diagnosed in childhood. |
What do you do to control type 1 diabetes? | You take insulin injections. |
Why do you take insulin injections instead of orally when treating type 1 diabetes? | Because hormones are proteins, it will be digested and broken down into amino acids instead. |
What is type 2 diabetes? | A condition that comes from your lifestyle, by having a high sugar diet or obesity. Your body no longer reacts to insulin. |
What do you do to control type 2 diabetes? | Exercise or a change in diet. |
What is testoterone? | A hormone that controls the development of secondary sexual characteristics in males. |
What is oestrogen? | A hormone that controls the development of secondary sexual characteristics in females. |
What are some secondary sexual characteristics found ONLY in females? | Hips widen.
Breasts develop.
Menstruation starts. |
What are some secondary sexual characteristics found ONLY in males? | Sperm is produced.
Facial hair grows.
Shoulders broaden. |
What are some secondary sexual characteristics found both in males and females? | Voice deepens.
Pubic hairs grow. |
What are the hormones involved in the menstrual cycle? | FSH, Oestrogen, LH and Progesterone. |
What does FSH do? | It matures the egg, released from the pituitary gland. |
What does oestrogen do? | It thickens the uterus lining and inhibits FSH. |
What does LH do? | It causes ovulation (the releasing of the egg). |
What does progesterone do? | It maintains the uterus lining. |
What happens in days 1-7 in the menstrual cycle? | FSH causes a new egg to mature. This stimulates oestrogen, thickening the uterus lining. |
What happens in days 8-13 inn the menstrual cycle? | FSH is inhibited by the oestrogen, and LH is now released. By now, the bleeding has stopped. |
What happens on day 14 in the menstrual cycle? | LH is at its highest and an egg is now released (ovulation). |
What happens in days 15-28 in the menstrual cycle? | Due to the release of the egg, oestrogen and progesterone levels are high.
The progesterone inhibits LH.
If the egg isn't fertilised, oestrogen and progesterone levels decrease, causing the lining to shed, restarting the period.
if an egg is fertilised, oestrogen and progesterone levels stay high to maintain the conditions. |
What is the menstrual cycle? | A period of time where an egg is released to be fertilised that takes roughly 28 days. |
Describe the sequence of hormonal interactions in the menstrual cycle. | FSH is released to mature and egg, causing OESTROGEN to be released, thickening the uterus lining.
This inhibits FSH, as LH is released until the levels reach its peak.
When the egg is released, OESTROGEN and PROGESTERONE is released to thicken and maintain the lining, stopping the secretion of LH.
If the egg is fertilised, PROGESTERONE and OESTROGEN levels stay high.
If the egg isn't fertilised, PROGESTERONE and OESTROGEN levels decrease and the process repeats. |
What is hormonal contraception? | Something that contains oestrogen and progesterone since it inhibits FSH and prevents the egg from maturing. |
What is non-hormonal contraception? | Physical barriers that prevent the meeting of the egg and sperm. |
What are some examples of hormonal contraception? | Oral contraceptives, implants, injections, patches or hormonal IUD's. |
What are some examples of non-hormonal contraception? | Condoms, surgical methods, copper IUD's, spermicidal agents or diaphragms. |