Endrocrinology Flashcards
Chemical messengers in the body to produce biochemical changes; Increase level of activity of a process
Hormone
Major Function of Hormone
Feedback Mechanism
Feedback Mechanism consists of (2)
- Positive Feedback Mechanism
- Negative Feedback Mechanism
Decrease in the product; Increases the activity of the system and the production rate
Positive Feedback Mechanism
Increase in the product decreases the activity of the system and the production rate
Negative Feedback
- Each Hormone is produced in a specific Endocrine gland
- Hormones are released into blood circulation and carried to site of action as FREE hormone or bound to transport protein
- Each hormone acts at a specific site (target organs) to induce certain characteristics, biochemical changes
Characteristics of Hormone
Classification of Hormones by Tissue Origin:
TRH, CRF, GnRH
Hypothalamus
Classification of Hormones by Tissue Origin:
FSH
LH
GH
PRL
TSH
ACTH
Anterior Pituitary Gland
Classification of Hormones by Tissue Origin:
Vasopressin
Oxytocin
Posterior Pituitary Glans (Storage only)
Classification of Hormones by Tissue Origin:
Epinephrine
Norepinephrine
Adrenal Medulla
Classification of Hormones by Tissue Origin:
Cortisol
II-Deoxycortisol
Aldosterone
Adrenal Cortex
Classification of Hormones by Tissue Origin:
T3
T4
Calcitonin
Thyroid
Classification of Hormones by Tissue Origin:
PTH
Parathyroid
Classification of Hormones by Tissue Origin:
Insulin
Glucagons
Pancreas
Classification of Hormones by Tissue Origin:
Estrogens
Ovaries
Classification of Hormones by Tissue Origin:
Testosterone
other Androgens
Testes
Types of Hormone Actions:
Act directly upon themselves
Autocrine
Types of Hormone Actions:
Act adjuscent to the cells of origin
Paracrine
Types of Hormone Actions:
Acts within the cell of origin without exiting the cells
Intracrine
Types of Hormone Actions:
Secreted in one location and release into BLOOD CIRCULATION, binds to specific receptor to elicit action
Endocrine
Types of Hormone Actions:
Secreted in endocrine cells and remains in relation to plasma membrane
Acts on immediately adjascent cells by DIRECT CELL TO CELL contact
Juxtacrine
Types of Hormone Actions:
Endocrine cells and interacts with receptors of cells at distant site
SECRETED INTO DUCTS
Exocrine
Hormone Classification by Structure:
About 2/3 of hormones are proteins or peptides
Does not require transport proteins
Proteins/Peptides
Insulin, PTH, LH, FSH, TRH, ACTH, Prolactin, GH, Calcitonin, Glucagon, TSH. HCG
Hormone Classification by Structure:
Primarily involved in regulation of sexual development and characteristics ; Require Transport Protein
Steroid
Hormone Classification by Structure:
Main component of Steroid
Cholesterol
Hormone Classification by Structure:
Steroid containing hormones
Cortisol
Estrogen
Estradiol
Estrone
Progesterone
Testosterone
Androgen
Hormone Classification by Structure:
Tyrosine as the precursor; can convert to Epinephrine and norepinephrine
Amino Acid
Hormone Classification by Structure:
Amino acid containing hormones
T3
T4
Ephinephrine
Norepinephrine
Hormone Classification by Structure:
classification of hormones that is being formed from ARACHIDONIC ACID
Fatty Acid
Hormone Classification by Structure:
Fatty acid containing hormones
Prostaglandin
Located in the walls and floor of third ventricle
Hypothalamus
Link between ng CNS and endocrine system
Hypothalamus
Produces OXYTOCIN and VASOPRESSIN (ADH)
Supraoptic and Paraventricular Nuclei
Gland that attaches to the midbrain ; responsible in producing MELATONIN
Pineal gland
Hormone that inhibits Melanin; sleeping hormone; Maintains Circadian Rhythm
Melatonin
TRH secretes
TSH
Prolactin
GnRH secretes
LH
FSH
CRH secretes
ACTH
GHRH secretes
GH
Somatostatin inhibits
TSH
GH
Dopamine inhibits
Prolactin