B7 key vocab

adrenal gland

A gland located on top of a kidney that produces the hormone adrenalin. It can be referred to as an adrenal.

endocrine gland

An organ that makes and releases hormones into the blood.

hormone

Chemical messenger that is released into the blood from an endocrine gland and causes target cells to change how they work.

hormonal system

The collection of glands in the body that release hormones. This system controls long-term or widespread responses by the body to changes inside and outside the body.

ovary

Organ in the female reproductive system that releases egg cells and the hormones oestrogen and progesterone.

pancreas

Organ in the body that produces some digestive enzymes, as well as the hormones insulin and glucagon.

pituitary gland pit-you-i-tar-ee

An organ just below the brain that controls many activities of the body (e.g. metabolic rate and the menstrual cycle) by the release of hormones into the blood. It can be referred to as the pituitary.

sex hormone

Any hormone that affects reproduction (e.g. oestrogen, testosterone).

target organ

An organ on which a hormone has an effect.

testis

An organ in the male reproductive system that produces sperm cells and the hormone testosterone.

thyroid gland

A gland that releases the hormone thyroxine into the blood.

adrenalin

A hormone that is released from the adrenal glands when you are nervous or excited.

fight-or-flight response

Several responses that prepare the body for sudden action, including increased heart rate, increased blood flow to muscles, and release of glucose into the blood.

glycogen gly-co-jen

A polymer storage material made from glucose, particularly in liver cells

metabolic rate met-a-bol-ick

The overall rate at which chemical reactions take place in the body.

negative feedback

A control mechanism in which a change in a condition, such as temperature, causes the opposite change to happen and so brings the condition back to a normal level.

resting metabolic rate

The metabolic rate when the body is at rest.

thyroxine

A hormone released by the thyroid gland, which affects metabolic rate by changing how certain cells work (e.g. causes heart cells to contract more strongly).

contraception

The prevention of pregnancy.

fertilisation

Fusing of a male gamete with a female gamete.

menopause

When the menstrual cycle stops completely.

menstrual cycle

A monthly cycle involving the reproductive organs in women.

menstruation

The breakdown and loss of the thickened part of the uterus lining at the start of a woman’s menstrual cycle.

oestrogen

A hormone produced by the ovaries which repairs and thickens the lining of the uterus, stimulates the release of LH from the pituitary gland and inhibits FSH release

ovulation

The release of an egg from an ovary.

period

The ‘bleed’ that occurs during menstruation.

pregnancy

The time during which a fertilised egg develops in the uterus until the birth of the baby.

progesterone

One of the hormones released by the ovaries.

puberty

The stage of life when the body develops in ways that make it able to reproduce (e.g. production of sperm cells in testes, and the release of egg cells from ovaries).

Assisted Reproductive Technology (ART)

Technology that helps to increase the chance of pregnancy, such as the use of hormones to stimulate egg release.

clomifene therapy

A form of therapy used to stimulate ovulation.

corpus luteum

A structure formed from the egg follicle after an egg cell is released from an ovary. It produces progesterone.

egg follicle

Cells in the ovary that surround a developing egg. The follicle produce hormones, such as oestrogen.

follicle-stimulating hormone (FSH)

A hormone produced by the pituitary gland that causes egg cells to mature in ovaries.

in vitro fertilisation (IVF)

Fertilising an egg cell by placing it in a sterile container then adding sperm cells.

luteinising hormone

A hormone produced by the pituitary gland that causes ovulation.

diabetes

A disease in which the body cannot control blood glucose concentration at the correct level.

glucagon

A hormone that increases blood glucose concentration.

homeostasis

Controlling the internal environment of the body at stable levels.

insulin

A hormone that decreases blood glucose concentration by causing cells to take in glucose. It is used in the treatment of type 1 diabetes.

type 1 diabetes

A type of diabetes in which the pancreas does not produce insulin.

body mass index (BMI)

An estimate of the amount of fat in a person’s body, using their mass and height, on which judgements of health are made.

correlation

A relationship between two variables, so that if one variable changes so does the other correlation can be positive or negative.

type 2 diabetes

A type of diabetes in which cells do not respond to insulin, or too little insulin is produced.

waist - hip ratio

An estimate of the amount of the fat in the body, calculated by dividing the waist measurement by the hip measurement. It can be used to make judgements about health.

dermis

Layer below the epidermis of the skin, which contains temperature receptors, sweat glands and erector muscles.

epidermis

Outer layer of skin.

erector muscle

Muscle in the skin dermis that contracts and raises a body hair.

fever A core body temperature that is too high (above 38 °C).

hypothalamus

Part of the brain that monitors and controls body temperature.

hypothermia

A core body temperature that is too low (below 36 °C).

negative feedback

Where a change in a system causes a response that brings about the opposite change, returning the system to a ‘normal’ level.

shivering

Rapid contraction and relaxation of muscles that causes the body to warm up.

thermoregulation

The control of body temperature, especially in core parts of the body (e.g. heart, liver and brain).

vasoconstriction vay-so-con-strik-shun

Narrowing of blood vessels, which reduces blood flow.

vasodilation vay-so-die-lay-shun

Widening of blood vessels, which increases blood flow.

antigen

A substance on the outside of a cell that the immune system uses to identify whether the cell is from the same body or a different one.

dialysis die-al-i-sis

Process used to clean the blood of people with kidney failure. It involves the exchange of substances between blood and dialysis fluid across a partially permeable membrane.

kidney

The organ that removes urea, excess water and other substances from the blood to form urine.

kidney failure

When both kidneys do not work properly.

organ donation

The transfer of a healthy organ (e.g. kidney) into the body of someone whose own organ has failed.

osmoregulation

The control of the balance of water and mineral ions in the body.

rejection

When the immune system attacks cells, tissues or an organ that has been placed in the body.

urea

A waste product from the breakdown of excess amino acids in the liver.

urinary system

Body system that removes excess substances and waste products from the body in urine.

active transport

The movement of particles across a cell membrane from a region of lower concentration to a region of higher concentration (against the concentration gradient). The process requires energy.

ADH

Antidiuretic hormone. Hormone produced by the pituitary gland that increases the permeability of the collecting duct in a nephron to water.

Bowman’s capsule

The start of a nephron where filtration occurs.

collecting duct

The final part of a nephron.

dehydrated

Lacking in water.

filtration (in kidney)

Separating large molecules from smaller ones, as in the glomerulus and Bowman’s capsule of a nephron.

first convoluted tubule

Part of a nephron where selective reabsorption of glucose and some mineral ions takes place.

glomerulus

A network of blood capillaries associated with the Bowman’s capsule of a nephron.

loop of Henle

Long loop of a nephron involved in osmoregulation.

microvilli

Finger-like projections of the cell surface membrane that greatly increase its surface area.

nephron

Long tubule found in the kidney where filtration of blood occurs, and reabsorption of useful substances, leaving waste and excess substances in urine.

permeability

A measure of how well a membrane allows substances to pass through it. More permeable membranes allow more substances through.

pituitary gland

Part of the brain that detects changes in the body and controls them by releasing many hormones.

selective reabsorption

Taking back particular (useful) substances, such as glucose and some mineral ions, into the nephron.

urine

A fluid produced by the kidneys, containing urea and other waste or excess substances dissolved in water.