BIOL 365 (Animal Phys) Flashcards
What is the difference between a conformer and a regulator?
A conformer allows its internal parameters to change with the external environment; a regulator responds to environmental change to maintain its internal parameters within a set range.
What is the difference between direct and indirect cell signalling?
Direct signalling transfers molecules from the cytoplasm of one cell to the cytoplasm of a neighbouring cell (via gap junctions); indirect signalling requires the release of chemical messengers into extracellular space.
What is a gap junction?
An aqueous channel formed between adjacent cells with aligned hemichannels made of connexins; used for direct cell signalling.
What is a chemical messenger?
A molecule that is released by a cell in response to some stimulus and transported to a target cell receptor to effect some change in the body.
What are connexins?
The protein subunits that make up the hemichannels forming each half of a gap junction between neighbouring cells.
What can be transferred via a gap junction?
Ions and chemical messenger molecules.
What is paracrine signalling?
A form of short-distance, indirect signalling in which a chemical messenger released by a cell is transported to a receptor on a different cell.
What is autocrine signalling?
A form of short-distance, indirect signalling in which a chemical messenger released by a cell is transported to a receptor on the same cell.
What are the two main mechanisms for short-distance, indirect cell signalling?
Autocrine and paracrine signalling.
What are the two main mechanisms for long-distance, indirect cell signalling?
Endocrine and nervous signalling.
What type of chemical messengers are used by the endocrine system?
Hormones.
What type of chemical messengers are used by the nervous system?
Neurotransmitters.
What triggers the release of neurotransmitters in the nervous system?
Action potentials.
What are the 7 classes of chemical messengers?
- Peptides
- Steroids
- Amines
- Lipids
- Purines
- Gases
- Amino acids
What structural property of a chemical messenger most significantly affects its signalling mechanism?
Hydrophobicity.
What are peptide hormones?
Hydrophilic chemical messengers composed of amino acids.
Where are peptide hormones synthesized?
On the rough ER.
In what form are peptide hormones usually produced initially?
Preprohormones (an inactive form).
In what form are peptide hormones usually stored?
Prohormones (an inactive form).
How are hydrophilic chemical messengers transported to target cells?
In vesicles.
What is usually cleaved off of an inactive peptide hormone during the transition from preprohormone to prohormone?
A signal peptide directing it to the appropriate vesicle.
Where is melatonin secreted?
Pineal gland.
What kind of hormone is melatonin?
Amine.
What does melatonin do?
Regulate circadean/seasonal rhythms.
Where are tropic hormones secreted?
Hypothalamus.
What kind of hormones are tropic hormones?
Peptide.
What do tropic hormones do?
Regulate the anterior pituitary gland.
Where is oxytocin secreted?
Posterior pituitary.
What kind of hormone is oxytocin?
Peptide.
What does oxytocin do?
Stimulates uterine contraction (during childbirth) and milk release.
Where is vasopressin secreted?
Posterior pituitary.
What kind of hormone is vasopressin?
Peptide.
What does vasopressin do?
Regulates water reabsorption in the excretory system.
Where are vasotocin, isotocin, and mesotosin secreted?
Posterior pituitary (in fish, amphibians, reptiles, and birds).
What kind of hormones are vasotocin, isotocin, and mesotocin?
Peptide.
What do vasotocin, isotocin, and mesotosin do?
Similar to mammalian vasopressin (water reabsorption) and oxytocin (birthing) in fish, amphibians, reptiles, and birds.
Where is prolactin (PRL) secreted?
Anterior pituitary.
What kind of hormone is prolactin (PRL)?
Peptide.
What does prolactin (PRL) do in mammals?
Stimulates milk production.
What does prolactin (PRL) do in fish?
Osmoregulation.
Where is growth hormone (GH) secreted?
Anterior pituitary.
What kind of hormone is growth hormone (GH)?
Peptide.
What does growth hormone (GH) do?
Regulates metabolism and growth.
Where is adrenocorticotropic hormone (ACTH) secreted?
Anterior pituitary.
What kind of hormone is adrenocorticotropic hormone (ACTH)?
Peptide.
What does adrenocorticotropic hormone (ACTH) do?
Regulates corticosteroid release.
Where is thyroid-stimulating hormone (TSH) secreted?
Anterior pituitary.
What kind of hormone is thyroid-stimulating hormone (TSH)?
Peptide.
What does thyroid-stimulating hormone (TSH) do?
Regulates thyroid hormone synthesis and release.
Where is follicle-stimulating hormone (FSH) secreted?
Anterior pituitary.
What kind of hormone is follicle-stimulating hormone (FSH)?
Peptide.
What does follicle-stimulating hormone (FSH) do?
Regulates egg/sperm production and sex hormone production.
Where is luteinizing hormone (LH) secreted?
Anterior pituitary.
What kind of hormone is luteinizing hormone (LH)?
Peptide.
What does luteinizing hormone (LH) do?
Regulates egg/sperm production and sex hormone production.
Where are triiodothyronine (T3) and thyroxine (T4) secreted?
Thyroid gland.
What kind of hormones are triiodothyronine (T3) and thyroxine (T4)?
Amines.
What do triiodothyronine (T3) and thyroxine (T4) do?
Regulate metabolism, growth, and development.
Where is calcitonin secreted?
Thyroid gland.
What kind of hormone is calcitonin?
Peptide.
What does calcitonin do?
Regulates plasma Ca2+ in nonhuman vertebrates.
Where is parathyroid hormone secreted?
Parathyroid gland.
What kind of hormone is parathyroid hormone?
Peptide.
What does parathyroid hormone do?
Regulates plasma Ca2+ and phosphate levels.
Where are thymosin and thymopoietin secreted?
Thymus gland.
What kind of hormones are thymosin and thymopoietin?
Peptide.
What do thymosin and thymopoietin do?
Regulate immune system development.
Where is atrial natriuretic peptide (ANP) secreted?
Atrium cells in the heart.
What kind of hormone is atrial natriuretic peptide (ANP)?
Peptide.
What does atrial natriuretic peptide (ANP) do?
Regulates sodium levels and blood pressure.
Where is angiotensin secreted?
Liver.
What kind of hormone is angiotensin?
Peptide.
What does angiotensin do?
Regulates aldosterone and blood pressure.
Where is insulin-like growth factor (IGF) secreted?
Liver.
What kind of hormone is insulin-like growth factor (IGF)?
Peptide.
What does insulin-like growth factor (IGF) do?
Regulates growth and metabolism.
Where are gastrin, cholecystokinin (CCK), secretin, and ghrelin secreted?
Stomach and small intestine.
What kind of hormones are gastrin, cholecystokinin (CCK), secretin, and ghrelin?
Peptides.
What do gastrin, cholecystokinin (CCK), secretin, and ghrelin do?
Regulate digestion, nutrient absorption, and food intake.
Where are insulin and glucagon secreted?
Pancreas.
What kind of hormones are insulin and glucagon?
Peptides.
What do insulin and glucagon do?
Regulate blood glucose.
Where is somatostatin secreted?
Pancreas.
What kind of hormone is somatostatin?
Peptide.
What does somatostatin do?
Regulates blood glucose, nutrients, growth, and metabolism.
Where is aldosterone secreted?
Adrenal cortex (mammals) or dispersed cells (other vertebrates).
What kind of hormone is aldosterone?
Steroid.
What does aldosterone do?
Ion regulation.
Where are glucocorticoids secreted?
Adrenal cortex (mammals) or dispersed cells (other vertebrates).
What kind of hormones are glucocorticoids?
Steroid.
What do glucocorticoids do?
Regulate ions, stress response, nutrient uptake & storage, and behaviour.
Where are androgen precursors secreted?
Adrenal cortex (mammals) or dispersed cells (other vertebrates).
What kind of hormones are androgen precursors?
Steroids.
What do androgen precursors do?
Regulate sex drive (females) or bone growth at puberty (males).
Where are epinephrine and norepinephrine secreted?
Adrenal medulla (mammals) or chromaffin cells (other vertebrates).
What kind of hormones are epinephrine and norepinephrine?
Amines.
What do epinephrine and norepinephrine do?
Regulate stress response and the cardiovascular system.
Where is stanniocalcin secreted?
Corpuscles of Stannius (fish) or various tissues (mammals).
What kind of hormone is stanniocalcin?
Peptide.
What does stanniocalcin do?
Regulates plasma Ca2+ in fish.
Where is erythropoietin (EPO) secreted?
Kidneys.
What kind of hormone is erythropoietin (EPO)?
Peptide.
What does erythropoietin (EPO) do?
Regulates red blood cell production.
Where is leptin secreted?
Adipose tissue.
What kind of hormone is leptin?
Peptide.
What does leptin do?
Regulates food intake, metabolism, and reproduction.
Where is inhibin secreted?
Testes (males) or ovaries (females).
What kind of hormone is inhibin?
Peptide.
What does inhibin do?
Regulates sex hormones.
Where are androgens secreted?
Testes (males).
What kind of hormones are androgens?
Steroids.
What do androgens do?
Regulate sperm production and secondary sexual characteristics.
Where are estrogens and progesterone secreted?
Ovaries or placenta (pregnant female mammals).
What kind of hormones are estrogens and progesterone?
Steroids.
What do estrogens and progesterones do in the ovaries?
Regulate egg production and secondary sexual characteristics.
What do estrogens and progesterone do in the placenta of pregnant female mammals?
Regulate fetal and maternal development.
Where is chorionic gonadotropin (CG) secreted?
Placenta (pregnant female primates and horses).
What kind of hormone is chorionic gonadotropin (CG)?
Peptide.
What does chorionic gonadotropin (CG) do?
Regulates fetal and maternal development in pregnant female primates and horses.
Where is chorionic somatomammotropin (CS; a.k.a. placental lactogen) secreted?
Placenta (pregnant female primates, rodents, and ruminants).
What kind of hormone is chorionic somatomammotropin (CS; a.k.a. placental lactogen)?
Peptide.
What does chorionic somatomammotropin (CS; a.k.a. placental lactogen) do?
Regulates fetal and maternal development in pregnant female primates, rodents, and ruminants.
