Endocrine System 1 Flashcards
What are some regulatory functions of the endocrine system?
Metabolism
Ion regulation
Water balance
Tissue maturation
Immune system regulation
Heart rate and blood pressure
Control of reproductive functions
Control of food intake and metabolism
Control of blood glucose and other nutrients
What are the 10 Endocrine Glands?
Hypothalamus
Pineal
Pituitary
Thyroid
Parathyroid (posterior thyroid)
Thymus
Adrenals
Pancreas
Ovaries
Testes
What are the similarities between the NERVOUS and ENDOCRINE system?
Both systems associated with the brain
* Hypothalamus
* Epithalamus
May use same chemical messenger as
neurotransmitter and hormone.
* Epinephrine
Two systems are cooperative
* Nervous system secretes neuroendocrine peptides, or neurohormones, into circulatory system
* Some parts of endocrine system innervated directly
by nervous system
What are the differences between the NERVOUS and ENDOCRINE system?
Mode of transport
Axon=N
Blood=E
Speed of response
Nervous – instant/milliseconds
Endocrine – delayed/seconds
Duration of response
Nervous – milliseconds/seconds
Endocrine – minutes/days
What are the two basic types of hormones?
lipid-soluble
water-soluble
What are the two sub divisions of hormones?
◦ Steroid hormones
◦ Non-steroid hormones
What are the characteristics of lipid-soluble hormones?
Non-polar=equally charged
Travel in blood bound to binding proteins
◦ Small
◦ Low solubility
◦ Slower degradation → longer half life
What are some examples of lipid-soluble hormones?
◦ Steroid hormones
◦ Thyroid hormones
◦ Fatty acid derivative hormones
What are the characteristics of water-soluble hormones?
Polar molecules
Can dissolve in the blood → many circulate as free hormones
Many are quite large so can’t readily diffuse through plasma membranes → slower diffusion
Capillaries of organs regulated by protein hormones are generally very porous
Some are quite small so attach to larger protein to avoid being filtered out of the blood
What are some examples of water soluble hormones?
◦ Protein hormones
◦ Peptide hormones
◦ Most amino acid derivative hormones
What are hormone receptors?
Transported in blood so come into contact with virtually all body tissues
Lock and key binding ensures they can only activate in a specific location
Either alters the cell’s existing proteins or turning on genes that will build a new protein
What are the 3 patterns of hormone secretion?
Chronic hormone secretion. Maintenance of relatively constant concentration of hormone. Thyroid hormone.
Acute hormone secretion. Epinephrine in response to stress.
Episodic (Cyclic) hormone secretion. Female reproductive hormones.
What are the characteristics of chronic hormone secretion?
A relatively stable concentration of hormone is maintained in the circulating blood over a relatively long period. This pattern is exemplified by the thyroid hormones.
What are the characteristics of acute hormone secretion?
A hormone rapidly increases in the blood for a short time in response to a specific stimulus—for example, Insulin (the blood sugar–regulating hormone)
Secretion following a meal. Note that the size of the stimulus arrow
represents its strength. A smaller stimulus does not activate as much
hormone secretion a s a larger stimulus
What are the characteristics of Episodic hormone secretion?
A hormone is stimulated so that it increases and decreases in the blood at a relatively consistent time and to roughly the same amount. Examples are the reproductive hormones regulating menstruation.
