5E-Endocrine System

unit 1 bio

hormone

a chemical messenger that causes a cellular response

hormone secretion + reception

• endocrine cell produces and secretes a hormone

• hormone travels along the bloodstream

• hormone arrives at target cell

• hormone binds to a receptor on the target cell

• target cell undergoes a response

difference between endocrine system and nervous system

regulates activities that require duration rather than speed

endocrine sends signals through hormones whereas nervous sends electrical impulses

hypothalamus

• secretes many hormones

• regulates many body activities and maintains homeostasis

Pituitry gland

• produces many hormones including growth hormone

• ‘the master gland’ of endocrine system

thyroid gland

• produces thyroxine hormone

• regulates metabolism and growth

adrenals

• produce cortisol and adrenaline

• regulate the body’s metabolism and response to stress

pancreas

• produces insulin and glucagon

• regulates blood glucose concentrations

cells in gonads

• testes=testosterone

• ovaries=progesterone and oestragens

• regulates fertility and secondary sex characteristics

two main types of hormones

• steroid

• peptide

steroid hormones

• lipids

• hydrophobic

• can transverse the plasma membrane

peptide hormones

• proteins

• hydrophilic

• cannot enter the cell so it they bind to cell membrane receptors

hormone signal transduction

signal - transduction - response