Endocrine System Flashcards
Name functions of the endocrine system
Acts with nervous system to coordinate and combine activity of body cells Regulates ;
- growth
- metabolism
- reproduction
- water - electrolyte - nutrient balance
Differences between hormonal and neural controls of body functioning
Hormonal :
- releases chemical msgs to blood stream
- target cells, ANY area of body
- changes metabolic activity
- SLOWER onset but LONGER in duration
Neutral :
- controls body functions
- electrical nerve impulses
- msg is delivered to SPECIFIC cells/organs ( muscle cells, glands)
- QUICK response
Hormone definition
Chemical messengers in terms of endocrine cells specifically which release these hormones which are transported into the blood stream and alter specific activity of target organ
Target cell definition
Tissues which contain a receptor for a specific hormone and depend on factors such as ;
- blood levels of hormone
- number of receptors on target cell
- how strong they bind between receptor and hormone
Receptor definition
Proteins that sit in the target cell and bind with a hormone which leads to change (nucleus, the body area in which a response is created)
Describe between lipid soluble hormones and water soluble hormones
Water soluble : Specific as they sit on the plasma membrane
Lipid soluble : made up of phospholipids and can dive inside the cell and find receptors inside the cell ( intracellular receptors ) which activate genes
How does glucose regulation work
Glucose - cells take it up which generate ATP which creates C02 -
But when we need glucose body breaks down glucagon to produce glucose
Endocrine glands include ;
- pituitary gland
- thyroid gland
- parathyroid glands
- adrenal glands
- pineal gland
Organs that contain in the current issues include ;
- pancreas
- ovaries/testes
- gastro intestinal tract
- kidney
- heart
- placenta
Water soluble hormones function
What are soluble hormones ( all amino acid based hormones except thyroid hormone )
- act on the plasma membrane receptors
- act via G protein second messages
- cannot enter cell
Lipid - soluble hormones functions
- steroid and thyroid hormones
- act on intra - cellular receptors that directly activate genes
- can enter cell
Steps of lipid soluble steroid hormones
- Steroid hormone defuses into plasma membrane and binds to intracellular receptor
- receptor hormone complex enters the nucleus
- the receptor hormone and complex binds to specific DNA region
- binding helps initiate transcription of the team to create mRNA
- mRNA direct protein synthesis
Cyclic AMP ( cAmp) signalling mechanism
- Hormone first messenger binds to receptor
2. Receptor activates as G protein
- G protein activates adenylase Cyclase
- Adenylase Cyclase converts ATP into cAMP second messenger
- cAMP activates protein kinases
Anterior pituitary hormones
- Adrenocorticotropic hormone (ACTH)
- Thyroid Stimulating hormone ( TSH)
- Lutenizing hormone & Follicle stimulating hormone ( LH & FSH)
- Prolactin ( PRL)
- Growth hormone ( GH)
Target/ function of Adrenocorticotropic hormone (ACTH )
Target : Adrenals
Function: stimulates adrenal gland to create cortisol also known as corticotropin

