Week 13 - Neuro-Endocrine System Flashcards
Neuroendocrine system (2) Nervous system uses Endocrine system releases
- Uses neurotransmitters
- Releases hormones
Endocrine glands release
Release hormones directly into the blood
Hormone purpose
Alter the activity of tissues that possess receptors to which the hormone can bind
Hormone definition
Chemical messengers from endocrine glands that travel in the blood placing them in direct contact with all cells.
-Can travel in the blood to their specific target organs
Receptor are ____ to hormones
specific
Each cell has ____ to _____ specific receptors
2000, 10,000
The ____ plasma hormone concentration determines the magnitude of the effect at the _____ level
free
tissue
Blood hormone concentration determined by rate of: (2)
- Secretion of hormone from endocrine gland
- Metabolism or excretion of hormone (at the receptor and by the liver and kidneys)
Blood hormone concentration determined by quality of____ _____(____ _____)
Transport protein (steroid hormone)
Blood hormone concentration determined by changes in ____ ____
plasma volume
Hormones affect only tissue with ____ _____
Specific receptors
Magnitude of Hormone-Receptor interaction depends on: (3)
- concentration of the hormone
- number of receptors on the cell
- affinity of the receptor for the hormone
Downregulation
Decrease in receptor number; in response to high concentration of hormone
Upregulation
Increase in receptor number in response to low concentration of hormones
Mechanisms of hormone action (3)
- Altering membrane transport (insulin)
- Stimulate DNA to increase protein synthesis (steroid hormone)
- Activating second messengers via G-protein (cyclic AMP)
Steroid Hormone characteristics (4)
- Lipid soluble
- Diffuses easily through cell membranes; receptor located within cell
- Chemical structure is derived from or is similar to cholesterol
- Secreted by adrenal cortex (e.g. cortisol), ovaries (e.g. oestrogen), testes (e.g. testosterone)
Non steroid hormone characteristics (3)
- Nonlipid soluble
- Cannot easily diffuse through cell membranes; receptors located on cell membranes
- Two types: amino acid derivatives (e.g. epinephrine) and protein or peptide hormones (e.g. insulin)
Anterior Pituitary gland hormones (3)
Adrenocorticotropic hormone (ACTH) Thyroid-stimulating hormone (TSH) Growth hormone (GH)
Posterior pituitary gland
Antidiuretic hormone (ADH)
Growth hormone Purpose
Stimulate release of insulin-like growth factors
Growth hormone essential growth of ____tissues
e.g.___ ___ uptake and _____ synthesis.
____ bone growth
All
amino acid, protein
Long
Growth hormone reduces the use of ____.
Increases________
Mobilizes____ ____ from _____ tissue
plasma glucose
gluconeogenesis
fatty acids from adipose tissue
Anti Diuretic hormone stimulated by
High plasma osmolality and low plasma volume (due to sweat loss without water replacement)
Anti diuretic hormone reduces
water loss from the body to maintain plasma volume (favours reabsorption of water from the kidney)
Thyroid gland hormones (2)
Triiodothyonine (T3)
Thyroxine (T4)
T3 and T4 purpose (2)
maintenace of metabolic rate
allowing the full effect of other hormones
Adrenal Medulla
hormones
Name of Hormones receptor
Effects depend on
Epinephrine, noepinephrine
bind to adrenergic receptors (alpha, beta)
Hormone used and receptor type
Adrenal cortex hormones
purpose of hormone (2)
Aldosterone (mineralcorticoid)
controls Na+ reabsorption and K+ secretion
regulation of blood volume and blood pressure
Aldosterone stimulated by (2)
increased K+ concentration
decreased plasma volume
Adrenal gland hormone
purpose (4)
Cortisol (glucocorticoid)
- Promotes protein breakdown for gluconeogenesis and tissue repair
- Stimulates FFA mobilization, glucose synthesis
- Blocks uptake of glucose into cells (promotes use of FFA’s as fuel)
Cortisol stimulated by (2)
Stress, via ACTH
Exercise
Hormones of the pancreas (2)
Insulin from beta cells
Glucagon from alpha cells
Insulin purpose
promotes the storage of glucose, amino acids and fats
Glucagon purpose
promotes the mobilization of fatty acids and glucose
Testes
Testosterone (anabolic steroid)
tissue building
performance enhancement
Ovaries produce____
Function
Estrogen
- establish and maintain reproductive function
- levels vary throughout the menstrual cycle
Blood glucose maintenance controlled by_____
hormones (corisol, growth hormone)
Plasma glucose maintained through 4 processes:
- Mobilization of glucose from liver glycogen stores, FFA from adipose tissue
- Gluconeogenesis from amino acids, lactic acid, and glycerol
- Blocking the entry of glucose into cells
Master gland also known as____ ____
Its purpose
pituitary gland
regulates activity of endocrine glands
