Chapter 41 - Chemical Signals in Animals Flashcards
Insulin
Decrease blood glucose level
Secreted by: beta-cells in pancreas
Antagonistic to glucagon
Glucagon
Glucagon
Increases blood glucose level
Secreted by: alpha-cells in pancreas
Tropic hormone
stimulates other endocrine gland to secrete hormones
(target cells are other endocrine glands)
Non-tropic hormone
directly causes response by binding to specific receptor
e.g. PEG - Prolactin, Endorphin, Growth hormones
Endocrine
- intercellular communication
- ductless gland
- receptors on target cells
- secreted into bloodstream
e. g. hormone
Exocrine
- extracellular communication
- gland with duct
e.g. sweat, sebum, digestive enzyme
Epinephrine (adrenaline)
= norepinephrine = adrenaline = noradrenaline
nor = methyl group absent
hydrophilic amine hormone
- belongs to catecholamine (two hydroxy phenols and amine)
- neurotransmitter
- produced in: adrenal medulla
- role: fight/flight response - raises blood glucose level, acts on pancreas, smooth muscle, digestive system
5 types of intercellular communication
1) Endocrine signaling
2) Paracrine signaling (local)
3) Autocrine signaling (local)
4) Synaptic signaling
5) Neuroendocrine signaling
Endocrine signaling
- local
- signal molecule: hormone
- secreting cell: endocrine gland
- route: blood stream to target cell with specific receptor
Paracrine signaling
- local
- signal molecule: local regulator
- secreting cell: neighbor cells
- route: interstitial fluid
e. g. cytokines, growth factors (polypeptides)
Autocrine signaling
- local
- signal molecule: local regulator
- secreting cell: they themselves are target cells
- route: interstitial fluid
e. g. cytokines, growth factors (polypeptides)
Synaptic signaling
- nervous system (neuron to neuron)
- signal molecule: neurotransmitter
- secreting cell: neurons (nerve cells)
- route: movement across synapse
e. g. inhibitory/excitatory neurotransmitters
Neuroendocrine signaling
- nervous system (neuron to bloodstream)
- signal molecule: neurohormones
- secreting cell: neurosecretory cells
- route: blood stream to target cell with receptor
e. g. oxytocin, ADH, TRH
ADH
antidiuretic hormone, vasopressin
produced in: hypothalamus
stored in : posterior pituitary gland
role: promotes retention of water by kidneys
TRH
TRH
Thyrotropin Releasing Hormone
tropic hormone
Prostaglandin
- local regulator (paracine, autocrine signaling)
- modified fatty acid
- found in prostate gland
- also in semen (cause contraction of uterine wall)
- promotes inflammation, pain sensing
Aspirin
painkiller
-blocks prostaglandin synthesis
(prostaglandin increases inflammation and immune response)
Ibuprofen
painkiller
-blocks prostaglandin synthesis
(prostaglandin causes inflammation)
Cytokines
polypeptides
enhance immune response
Nitrogen Oxide (NO)
- local regulator
- acts as neurotransmitter
-promotes vasodilation of blood vessel in penis (increases strength & duration of erection)
polypeptide (local regulator)
cytokines
growth hormones
Chemical classes of local regulators
1) prostaglandin
2) polypeptide
3) gas
Chemical classes of hormones
1) Polypeptide
2) amine
3) steroid
Polypeptide hormone
- most abundant
- hydrophilic
- binds to membrane receptors
e. g. insulin
Amine hormone
- contains amino group (NH2)
- hydrophilic
e.g. epinephrine
Dopamine
hydrophilic amine hormone
role: reward system
Thyroxine
hydrophobic amine hormone
produced in: thyroid gland
role: increases metabolic rate, but does not affect blood glucose level
Steroid hormone
(types)
Steroid hormone (types)
- hydrophobic
- structure: four fused ring
1) sex hormone
2) corticoid hormone
3) vitamin D
Sex hormone
-steroid hormone
testosterone
estradiol
Corticoid hormone
- steroid hormone
1) glucocorticoid (cortisol, cortisone) : increases blood glucose level but does not affect metabolism
2) mineralocorticoid (aldosterone) : absorbs mineral ions in distal convoluted tubule
Vitamin D
- steroid hormone
- causes Ca2+ absorption into blood
-deficiency syndrome : Rickets
Oxytocin
Produced in: hypothalamus
Stored in: posterior pituitary gland
Role: reward system, stimulates contraction of smooth muscle cells in uterus & mammary glands
Prolactin
Non-tropic hormone
Produced in: anterior pituitary gland
Role: stimulates mammary gland cells, breast milk production
TSH
Thyroid Stimulating Hormone
-tropic hormone
Produced in: Anterior pituitary gland
Role: stimulates thyroid gland
GnRH
Gonadotropin releasing hormone
-tropic hormone
ACTH
anterior pituitary gland
stimulates adrenals cortex to release…
Pituitary gland
“master gland”
1) anterior pituitary
- secretes: FSH, LH, ACTH, TSH, prolactin, endorphin, growth hormone (FLAT PEG)
2) posterior pituitary - secretes: oxytocin, vasopressin
Two modes of coordination and communication in our body
1) Nervous system
- fast, direct
- short-lasting
- travels through neural synapses
- messenger: neurotransmitters
2) Endocrine system
- slow, indirect
- long-lasting
- travels through blood
- messenger: hormones
List the major endocrine glands
Pituitary gland
Hypothalamus
Pineal gland
Thyroid gland
Parathyroid gland
Pancreas
Adrenal gland
Reproductive organs (ovary, testes)
Kidney
Digestive organ
Rickets
bone deformity
-caused by Ca2+ deficiency
Osteoporosis
bone softening
-caused by Ca2+ deficiency
Hypothalamus
- neuroendocrine gland = contains neurosecretory cells
- releases: (1) oxytocin (2) vasopressin (ADH) from posterior pituitary
Pineal gland
Hormone secreted: melatonin (sleep cycle, biorhythm)
FSH
Follicle Stimulating Hormone
Tropic hormone
Produced in: Anterior pituitary gland
Role: stimulates follicle to secrete estradiol
LH
LH
Luteinizing Hormone
Tropic hormone
Produced in: Anterior pituitary gland
Role: stimulates ovulation in women, stimulates corpus lute to produce progesterone
ACTH
Adrenocorticotropic hormone
Tropic hormone
Secreted by: anterior pituitary hormone
Role: stimulates adrenal cortex to secrete long term stress hormone
Growth hormone
BOTH tropic and non-tropic hormone
Secreted by: anterior pituitary gland
Role: stimulates growth & metabolic functions
*abnormality can cause gigantism, dwarfism
Thyroid gland
Hormone secreted: thyroid hormone (T3, T4), calcitonin
Thyroid hormone
Secreted by: thyroid gland
Role: stimulates & maintains metabolic processes
Calcitonin
Secreted by: thyroid gland
Role: lowers blood calcium level, increases bone calcium level
Parathyroid gland
Hormone secreted: parathyroid hormone
Parathyroid hormone
Secreted by: parathyroid gland
Role: raises blood calcium level, decreases bone calcium level
Adrenal glands
Hormones secreted:
1) Adrenal medulla: epinephrine
2) Adrenal cortex: glucocorticoids, mineralocorticoids
Pancreas
Hormones secreted: Insulin, glucagon
Ovaries
Hormones secreted: estrogens, progestins
Testes
Hormones secreted: androgens
Glucocorticoids
hydrophobic steroid (corticoid) stimulated by: adrenal cortex
role: raises blood glucose level, suppression of immune system
Mineralocorticoid
hydrophobic steroid (corticoid) stimulated by: adrenal cortex
role: promotes retention of Na+ and excretion of K+ in kidneys, absorbs mineral ions in distal convoluted tubule
Endorphin
Non-tropic, Peptide hormone
secreted by: anterior pituitary gland
role: natural analgesics (painkiller, relieve pain)
Long term stress response
Process:
1) stressful stimuli causes hypothalamus to activate adrenal cortex through hormonal signals
2) adrenal cortex stimulates mineralocorticoids and glucocorticoids
Short term stress response.
Process:
1) stressful stimuli causes hypothalamus to activate adrenal medulla through nerve impulses
2) Adrenal medulla secretes epinephrine
