hormones communication

UVI

acinus

a small group of exocrine cells in the pancreas around a tubule

adrenal cyclase

an enzyme that converted ATP to cAMP

adrenal cortex

the outer layer of the adrenal gland

adrenal gland

a gland on top of the kidney that secrets adrenaline (peptide) and corticosteroids (steroids)

adrenaline

a peptide hormone released from the adrenal medulla to start a fight/flight and amplify heart rate

adrenal medulla

the inner layer of the adrenal gland

alpha cells

cells in the islets of langerhans that secrete glucagon into tubules

AMP

adenosine monphophate

androgens

steroid hormones which reuglates sex hormone production

beta cells

cells in the islets of langerhans that secrete insulin into tubules

cell signalling

the communication between cells, often using chemicals and receptors

chemoreceptors

sensory receptors present on plasma membranes that detect chemical concentrations to form other chemical or electrical signals

cAMP

a secondary messenger in insulin response

diabetes mellitus

a condition where blood glucose levels are not controlled effectively

ectotherm

an organism that relies on external sources of heat

effector

a cell or tissue that starts a response

endocrine gland

a gland that secretes into blood

endocrine system

the hormone communication system

endotherm

an organism that can control its own body temperature via metabolic reactions

exocrine gland

a gland that secretes into a duct

first messengers

hormones used for cell signalling outside of a cell and often bind to receptors on plasma membranes

glucagon

a hormone that breaks down glycogen to glucose increasing blood glucose levels

glucocorticoid

steroid hormones (eg. cortisol in the adrenal cortex used for metabolism control and stress response)

gluconeogenesis

when amino acids and fast are converted into glucose

glycogenesis

when glucose is turned into glycogen for storage in the liver

glycogenolysis

when glycogen is turned into glucose by phosphorylase A

homeostasis

the maintenance of a constant internal environment, despite internal and external changes

hormonal system

a communication system that uses hormones in the blood also known as the endocrine system

hormone

proteins or steroids released by endocrine glands to act as messengers in the blood

hyperglycaemia

when blood glucose concentration is too high for a long period of time

hypoglycaemia

when blood glucose concentration is too low for a long period of

hypothalamus

an area in the brain in charge of controlling homeostasis and response

insulin

a hormone released by beta cells to reduce glucose levels in the blood

islets of langerhans

specialised cells in the pancreas which produce insulin and glucagon

metabolic waste

substances that are produced in excess by metabolic processes, this may causes cells to become toxic

mineralcorticoids

steroid based hormones (eg. aldosterone from the adrenal cortex controls sodium and potassium levels in blood to help maintain a steady blood pressure)

negative feedback

a feedback system where any change is reversed returning levels to an optimum

neuronal system

the interconnected set of neurones that allow signals to travel around the body and across synapses

neurone

a specialised cell for transmitting impulses by creating and action potential

neurotransmitter

a chemical signalling molecule between two neurones in a synapse

pituitary gland

an endocrine gland in the brain, under the hypothalamus. the anterior lobe secretes hormones and the posterior lobe acts as a store and releases the hormones produced

positive feedback

a mechanism that amplifies a change, moving further from optimum

releasing factors

hormones from the hypothalamus such as corticosteroid and thyrotropin releasing factor which stimulates other hormones to be released in the pituitary gland

receptors

extrinsic glycoproteins that bind to chemical signallers, causing a cell response

response

a change in an organism due to a simulus

second messenger

a signalling molecule inside a cell that stimulates a change in the activity of a cell

sensory receptor

a specialised cell which detects stimuli

shivering

a reflex in homeostasis which causes skeletal muscles to begin to shake to create warmth by using energy

stimulus

a change in the environment which may cause a response

target cells

cells that have a specific receptor on their plasma membrane, this complementary receptor can bind to chemical messengers. if there are many target cells in one area it becomes a target tissue

thermoregulation

the maintenance of a constant core body temperatures (around 36-37^oC)

thyroid stimulating hormone

a hormone stimulating the thyroid to secrete thyroxine, this is stimulated by the releasing factor thyrotorpin (TRH/TRF)

transducer

a cell that converts one type of energy to another (eg. chemical to electrical in neurones)

tropic hormones

hormones such as adrenal-corticotropic hormone stimulate endocrine glands to release hormones

type 1 diabetes mellitus

insulin dependent diabetes when beta cells do not synthesise enough insulin

type 2 diabetes mellitus

non-insulin dependent diabetes when cells do not react to insulin but still produces insulin in beta cells

diabetes insipidus

diabetes formed during gestation

vasoconstriction

the narrowing of blood vessels by contracting muscle walls in arterioles to shunt blood away from the skin. increasing distance causes less thermal energy to be lost to the environment

vasodilation

the widening of blood vessels by dilating muscle walls in arterioles to shunt blood to the skin. decreasing distance causes more thermal energy to be lost to the environment