Chapter 17- Endocrine system Flashcards
Endocrinology
study of structure and function of the endocrine glands and the
diagnosis and treatment of disorders of the endocrine system
Hormone
chemical messenger secreted by cells of an endocrine tissue/gland into the interstitial fluid that diffuses to the blood capillaries, is transported into the bloodstream to specific “target” cells, where it binds to a specific receptor and has an effect on that cell’s physiological activity
Endocrine Glands
pituitary, thyroid, parathyroid, adrenal and pineal glands
Organs with endocrine tissue
hypothalamus, thymus, pancreas, ovaries,
testes, kidneys, digestive tract, heart, adipose tissue and placenta
Tropic hormone
A tropic hormone is a hormone that tells another gland to make and release its own hormones. Think of it like a messenger or a boss that gives instructions to other glands in your body.
So, tropic hormones don’t directly do the job themselves—they signal other glands to get the job done!
Difference between endocrine tissue and gland
gland= directly produces hormone (pituitary)
endocrine tissue= some capacity to produce hormone but has other functions (hypothalamus)
Regulating physiology functions of hormones
-chemical composition of the ECF
-metabolism and energy balance
-biological clock
-contraction of smooth and cardiac muscle
-some immune system functions
Functions of hormones
-regulate many aspects of physiology
-control growth and development
-regulate the reproductive organs
Nervous system vs endocrine system mediator molecules
N= neurotransmitters
E= hormones
Nervous system vs endocrine system site of action
N= close to release site (synapse)
E= far away from release site (anywhere)
Nervous system vs endocrine system types of target cells
N= few cell types, neurons, muscle, glands
E= any body cells
Nervous system vs endocrine system time to onset of action
N= milliseconds
E= seconds to days
Nervous system vs endocrine system duration of action
N= shorter (msec)
E= longer (sec to days
Anterior pituitary physical characteristics
-sits within the sella turcica and sphenoid bone
-attached to the hypothalamus via the infundibulum
-under control of the hypothalamus
-largest portion
Releasing hormones from the hypothalamus
-gonadotropin-releasing hormone
-thyrotropin-releasing hormone
-corticotropin-releasing hormone
-prolactin-releasing hormone
-somatostatin/prolactin-inhibiting hormone
-growth hormone-releasing hormone
posterior pituitary hormones
-oxytocin
-antidiuretic hormone
-produced by neurons in the hypothalamus, stored on posterior, controlled release from neural response
histology of anterior pituitary
Grows upwards from primitive pharynx during embryological development, larger portion of pituitary gland
histology of posterior pituitary
- Grows downwards from the brain;
composed of nervous tissue - Stores hormones made by the
neurons in hypothalamus
7 anterior pituitary hormones
Prolactin (PRL)
Thyroid stimulating hormone (TSH)
Luteinizing hormone (LH)
Follicle-stimulating hormone (FSH)
Growth hormone (GH)
Adrenocorticotrophic hormone (ACTH)
Melanocyte-stimulating hormone (MSH)
Functions of GH-IGF action
1) Protein synthesis
- Tissue repair
2) Lipid metabolism
- Provides energy via fatty
acids + glycerol
- Spares protein
3) Carbohydrate metabolism
- Stimulates glucose
production by liver
4) Electrolyte balance
- Promotes Na+, K+, Cl-
retention by kidneys, increases
Ca2+ absorption by small
intestines
water soluble
-travel freely through blood stream
-no transport proteins
-catecholamines
-peptide hormones
-majority of hormones
lipid soluble
-need a transport protein to travel
-thyroid hormones
-Eicosanoids
-steroid hormones
tryptophan
is both water soluble and lipid soluble
-melatonin is derivative of tryptophan
