Endocrine systems Flashcards
What cells do hormones act in?
Only in cells with correct membrane receptor proteins (target cells)
What is communication by hormones also known as?
Humoral
What are examples of endocrine glands?
Hypothalamus
Parathyroid
Thyroid
Pancreas (islets)
Pituitary
Adrenal
What are steroids made from?
Cholesterol
What are examples of steroids?
Cortisol
Testosterone
Oestrogen
Progesterone
What are the two amino acid derivatives of non-steroid hormones?
Amines and Iodinated amino acids
What are examples of amines?
Adrenaline
Noradrenaline
Melatonin
What are examples of iodinated amino acids?
Triiodothyronine
Tetraiodothyronine
What are examples of peptide short chain hormones?
Oxytocin
Melanocyte stimulating hormone
Somatostatin
What are examples of long chain peptide hormones?
Growth Hormone
Insulin
Glucagon
PTH
Calcitonin
Secretin, CCK, gastrin
What is the inactive hormone called?
Precursor form
Where does the pre-hormone become the prohormone?
Endoplasmic reticulum
Where is the prohormone converted to active hormone?
Golgi Apparatus
Where are active hormones secreted from?
Vesicles
What are glycoproteins?
Proteins with attached carbohydrate groups to amino acids
What are examples of glycoproteins?
Follicle stimulating hormone
Thyroid stimulating hormone
Luteinizing hormone
What are local tissue hormones?
Hormone like substances which have a paracrine effect
What are examples of local tissue hormones?
Prostaglandins
Thromboxanes
What are functions of local tissue hormones?
Haemostasis
Inflammation
Mucosal Protection
Blood flow regulation
What are two common second messengers?
cAMP and Ca++
Can steroid hormones pass directly through outer cells into intracellular receptors?
Yes
What happens do hormones once they have made their effect?
They are excreted or metabolised
What are most hormone systems controlled by?
Negative feedback control
What is the name for excess secretion?
Hypersecretion
What is the name for decreased secretion?
Hyposecretion
What is the sensitivity of target cells related to?
Number of membrane receptors
What is the name for more receptors?
Upregulation