Chap 11 (Hormonal coordination) - Biology

Endocrine system

A system of glands that secrete hormones into the bloodstream.

Hormones

Chemical substances produced by glands that regulate various functions in the body.

Pituitary gland

Located in the brain; often referred to as the 'master gland' because it controls other glands and produces several hormones. controls growth in children, stimulates the thyroid gland to make thyroxine to control the rate of metabolism, in females – stimulates the ovaries to produce and release eggs, and make oestrogen, in males – stimulates the testes to make sperm and testosterone

Adrenaline

A hormone produced by adrenal glands that increases heart rate and prepares the body for 'fight or flight' response.

Thyroxine

A hormone produced by the thyroid gland that regulates metabolic rate and is important for growth.

Negative feedback

A process that helps to maintain balance by reversing changes in levels of substances in the body.

Pancreas

An organ that monitors and controls blood glucose levels by producing insulin and glucagon.

Type 1 diabetes

A form of diabetes where the pancreas produces insufficient insulin.

Type 2 diabetes

A form of diabetes where body cells do not respond to insulin; often associated with obesity.

Insulin

A hormone produced by the pancreas that lowers blood glucose levels.

Glucagon

A hormone produced by the pancreas that raises blood glucose levels.

FSH (Follicle Stimulating Hormone)

A hormone that stimulates the maturation of eggs in the ovaries.

LH (Luteinising Hormone)

A hormone that stimulates the release of a mature egg from the ovaries.

Oestrogen

The main female reproductive hormone, produced in the ovaries, which regulates the menstrual cycle.

Progesterone

A hormone that maintains the thick lining of the uterus.

Testes

The male reproductive glands that produce testosterone and sperm. controls development of male secondary sexual characteristics, involved in sperm production and maturation.

Ovaries

The female reproductive glands that produce oestrogen and eggs. controls the development of female secondary sexual characteristics and controls the mentral cycles

Menstrual cycle

A monthly cycle regulated by hormones that prepares the female body for potential pregnancy.

IVF (In Vitro Fertilisation)

A medical procedure in which fertilisation occurs outside the body to treat infertility.

Contraception

Methods used to prevent pregnancy during sexual intercourse.

Phototropism

The growth of plant shoots towards light, controlled by the hormone auxin.

Gravitropism

The growth of plant roots towards gravity, also influenced by auxin levels.

Auxin

A plant hormone that regulates growth by directing the development of shoots and roots.

Diabetes

A non-communicable disease characterized by uncontrolled blood glucose levels due to insulin issues.

Human development

The series of changes in the human body during growth, influenced by hormonal actions.

Gland

An organ that produces and secretes hormones for specific functions in the body.

Hormonal regulation

The process by which hormones control various functions and processes in the body.

Basal metabolic rate

The rate at which the body uses energy while at rest, influenced by thyroxine.

Stress response

The physiological reaction to a perceived threat, primarily mediated by adrenaline.

Secondary sexual characteristics

Physical traits that develop during puberty, influenced by sex hormones.

Fertility treatment

Medical procedures to address infertility, including hormonal treatments.

Spermicidal agents

Substances that kill or incapacitate sperm to prevent pregnancy.

Abstinence

Choosing not to engage in sexual intercourse as a method of contraception.

Sterilisation

Surgical methods employed to permanently prevent pregnancy.

Copper IUD

A non-hormonal intrauterine device that prevents fertilization by inhibiting sperm.

Luteal phase

The phase in the menstrual cycle after ovulation when the corpus luteum forms.

FSH control

Regulated by hormonal feedback mechanisms to manage egg maturation in females.

Thyroid role

controls the rate of metabolism in the body

Pancreas

controls blood glucose levels

Adrenal role

prepares the body for stress, involved in the ‘fight or flight’ response

How do the effects of the endocrine system compare to those of the nervous system?

endocrine system effects are slower but act for longer compared to the rapid, short-lived effects of the nervous system.

Where is the pituitary gland located?

brain

Which organ monitors and controls blood glucose concentration?

pancreas

Which hormones interact to regulate blood glucose levels?

insulin and glucagon

What is the cause of Type 1 diabetes?

pancreas produces insufficient insulin due to autoimmune destruction of insulin-producing beta cells.

What is the cause of Type 2 diabetes?

body cells no longer respond to insulin or the pancreas does not produce enough insulin.

What is the function of FSH?

causes eggs to mature in the ovaries, and stimulates ovaries to produce oestrogen

What is the function of LH?

stimulates the release of an egg

What are the methods of hormonal contraception?

oral contraceptives, injection, implant, skin patch, IUD

What are the methods of non-hormonal contraception?

barrier methods, copper IUD, spermicidal agents, sterilisation, abstinence

State the disadvantages of IVF treatment.

emotionally and physically stressful, low success rate, can lead to risky multiple births

What is the function of adrenaline in the body?

increases heart rate and boosts delivery of oxygen and glucose to brain and muscles to prepare the body for ‘fight or flight’

What is the function of thyroxine in the body?

stimulates basal metabolic rate, so is important for growth and development

Name one hormone controlled by negative feedback.

thyroxine

Which endocrine glands control secondary sexual characteristics?

ovaries in females, testes in males