ENDOCRINE SYSTEM Flashcards
Hormones of Hypothalamus:
- Thyrotropin-releasing hormone
- Corticotropin-releasing hormone
- Growth hormone-releasing hormone
- Growth hormone inhibitory hormone (somatostatin)
- Gonadotropin-releasing hormone
- Dopamine or prolactin-inhibiting factor
Chemical structures of Hypothalamus hormones:
- Thyrotropin-releasing hormone: PEPTIDE
- Corticotropin-releasing hormone: PEPTIDE
- Growth hormone-releasing hormone: PEPTIDE
- Growth hormone inhibitory hormone (somatostatin): PEPTIDE
- Gonadotropin-releasing hormone: PEPTIDE
- Dopamine or prolactin-inhibiting factor: AMINE
Hormones of Anterior pituitary:
- Growth Hormone
- Thyroid-stimulating hormone
- Adrenocorticotropic hormone
- Prolactin
- Follicle-stimulating hormone
- Luteinizing hormone
Chemical structures of Anterior pituitary hormones:
- Growth Hormone: PEPTIDE
- Thyroid-stimulating hormone: PEPTIDE
- Adrenocorticotropic hormone: PEPTIDE
- Prolactin: PEPTIDE
- Follicle-stimulating hormone: PEPTIDE
- Luteinizing hormone: PEPTIDE
Hormones of Posterior pituitary:
- Antidiuretic hormone (also called vasopressin)
- Oxytocin
Chemical structures of Posterior pituitary hormones:
- Antidiuretic hormone (also called vasopressin): PEPTIDE
- Oxytocin: PEPTIDE
Hormones of Thyroid:
- Thyroxine (T4) and Triiodothyronine (T3)
- Calcitonin
Chemical structures of Thyroid hormones:
- Thyroxine (T4) and Triiodothyronine (T3): AMINE
- Calcitonin: PEPTIDE
Hormones of Adrenal cortex:
- Cortisol
- Aldosterone
Chemical structures of Adrenal cortex hormones:
- Cortisol: STEROID
- Aldosterone: STEROID
Hormones of Adrenal medulla:
- Norepinephrine, epinephrine
Chemical structures of Adrenal medulla hormones:
- Norepinephrine, epinephrine: AMINE
Hormones of Pancreas:
- Insulin (beta cells)
- Glucagon (a cells)
Chemical structures of Pancreas hormones:
- Insulin (beta cells): PEPTIDE
- Glucagon (a cells): PEPTIDE
Hormones of Parathyroid:
- Parathyroid hormone
Chemical structures of Parathyroid Hormones:
- Parathyroid hormone: PEPTIDE
Hormones of Testes:
- Testosterone
Chemical structures of Testes hormones:
- Testosterone: STEROID
Hormones of Ovaries:
- Estrogens
- Progesterone
Chemical structures of Ovaries hormones:
- Estrogens: STEROID
- Progesterone: STEROID
Hormones of Placenta:
- Human chorionic gonadotropin
- Human somatomammotropin
- Estrogens
- Progesterone
Chemical structures of Placenta hormones:
- Human chorionic gonadotropin: PEPTIDE
- Human somatomammotropin: PEPTIDE
- Estrogens: STEROID
- Progesterone: STEROID
Hormones of Kidney:
- Renin
- 1,25-Dihydroxycholecalciferol
- Erythropoietin
Chemical structures of Kidney hormones:
- Renin: PEPTIDE
- 1,25-Dihydroxycholecalciferol: STEROID
- Erythropoietin: PEPTIDE
Hormones of heart:
- Atrial natriuretic peptide
Chemical structures of Heart hormones:
- Atrial natriuretic peptide: PEPTIDE
Hormones of Stomach:
- Gastrin
Chemical structures of Stomach hormones:
- Gastrin: PEPTIDE
Hormones of Small intestine:
- Secretin
- Cholecystokinin
Chemical structures of Small intestine hormones:
- Secretin: PEPTIDE
- Cholecystokinin: PEPTIDE
Hormones of Adipocytes:
- Leptin
Chemical structures of Adipocytes hormones:
- Leptin: PEPTIDE
WHAT HORMONE?
Stimulates the secretion of thyroid-stimulating hormone and prolactin
Thyrotropin-releasing hormone
WHAT HORMONE?
Causes release of adrenocorticotropic hormone
Corticotropin-releasing hormone
WHAT HORMONE?
Causes release of growth hormone
Growth hormone-releasing hormone
WHAT HORMONE?
Inhibits release of growth hormone
Growth hormone inhibitory hormone (somatostatin)
WHAT HORMONE?
Causes release of luteinizing hormone and follicle-stimulating hormone
Gonadotropin-releasing hormone
WHAT HORMONE?
Inhibits release of prolactin
Dopamine or prolactin-inhibiting factor
WHAT HORMONE?
Stimulates protein synthesis and overall growth of most cells and tissues
Growth hormone
WHAT HORMONE?
Stimulates synthesis and secretion of thyroid hormones (thyroxine and triiodothyronine)
Thyroid-stimulating hormone
WHAT HORMONE?
Stimulates synthesis and secretion of adrenocortical hormones (cortisol, androgens, and aldosterone)
Adrenocorticotropic hormone
WHAT HORMONE?
Promotes development of the female breasts and secretion of milk
Prolactin
WHAT HORMONE?
Causes growth of follicles in the ovaries and sperm maturation in Sertoli cells of testes
Follicle-stimulating hormone
WHAT HORMONE?
Stimulates testosterone synthesis in Leydig cells of testes; stimulates ovulation, formation of corpus luteum, and estrogen and progesterone synthesis in ovaries
Luteinizing hormone
WHAT HORMONE?
Increases water reabsorption by the kidneys and causes vasoconstriction and increased blood pressure
Antidiuretic hormone (also called vasopressin)
WHAT HORMONE?
Stimulates milk ejection from breasts and uterine contractions
Oxytocin
WHAT HORMONE?
Increases the rates of chemical reactions in most cells, thus increasing body metabolic rate
Thyroxine (T4) and Triiodothyronine (T3)
WHAT HORMONE?
Promotes deposition of calcium in the bones and decreases extracellular fluid calcium ion concentration
Calcitonin
WHAT HORMONE?
Has multiple metabolic functions for controlling metabolism of proteins, carbohydrates, and fats; also has anti-inflammatory effects
Cortisol
WHAT HORMONE?
Increases renal sodium reabsorption, potassium secretion, and hydrogen ion secretion
Aldosterone
WHAT HORMONE?
Same effects as sympathetic stimulation
Norepinephrine, epinephrine
WHAT HORMONE?
Promotes glucose entry in many cells, and in this way controls carbohydrate metabolism
Insulin (beta cells)
WHAT HORMONE?
Increases synthesis and release of glucose from the liver into the body fluids
Glucagon (a cells)
WHAT HORMONE?
Controls serum calcium ion concentration by increasing calcium absorption by the gut and kidneys and releasing calcium from bones
Parathyroid hormone
WHAT HORMONE?
Promotes development of male reproductive system and male secondary sexual characteristics
Testosterone
WHAT HORMONE?
Promotes growth and development of female reproductive system, female breasts, and female secondary sexual characteristics
Estrogens
WHAT HORMONE?
Stimulates secretion of “uterine milk” by the uterine endometrial glands and promotes development of secretory apparatus of breasts
Progesterone
WHAT HORMONE?
Promotes growth of corpus luteum and secretion of estrogens and progesterone by corpus luteum
Human chorionic gonadotropin
WHAT HORMONE?
Probably helps promote development of some fetal tissues, as well as the mother’s breasts
Human somatomammotropin
WHAT HORMONE?
Catalyzes conversion of angiotensinogen to angiotensin I (acts as an enzyme)
Renin
WHAT HORMONE?
Increases intestinal absorption of calcium and bone mineralization
1,25-Dihydroxycholecalciferol
WHAT HORMONE?
Increases erythrocyte production
Erythropoietin
WHAT HORMONE?
Increases sodium excretion by kidneys, reduces blood pressure
Atrial natriuretic peptide
WHAT HORMONE?
Stimulates hydrogen chloride secretion by parietal cells
Gastrin
WHAT HORMONE?
Stimulates pancreatic acinar cells to release bicarbonate and water
Secretin
WHAT HORMONE?
Stimulates gallbladder contraction and release of pancreatic enzymes
Cholecystokinin
WHAT HORMONE?
Inhibits appetite, stimulates thermogenesis
Leptin
Types of Chemical Messenger Systems:
- Neurotransmitters
- Endocrine Hormones
- Neuroendocrine Hormones
- Paracrines
- Autocrines
- Cytokines
Types of Chemical Messenger Systems:
______: Released by neuron axon terminals into synapses to control nearby nerve cells.
Neurotransmitters
Types of Chemical Messenger Systems:
______: Released by glands into the bloodstream to act on distant target cells.
Endocrine Hormones
Types of Chemical Messenger Systems:
______: Secreted by neurons into the blood to influence distant target cells.
Neuroendocrine Hormones
Types of Chemical Messenger Systems:
______: Secreted into extracellular fluid to affect nearby different cell types.
Paracrines
Types of Chemical Messenger Systems:
______: Secreted into extracellular fluid to act on the same cells that produce them.
Autocrines
Types of Chemical Messenger Systems:
______: Peptides in extracellular fluid that act as autocrines, paracrines, or endocrine hormones.
Cytokines
Structure and Synthesis of Hormones:
- Proteins and polypeptides
- Steroids
- Derivatives of the amino acid tyrosine
Structure and Synthesis of Hormones:
Proteins and polypeptides, including hormones secreted by the ______ and ______, the ______ (insulin and glucagon), the ______ (parathyroid hormone), and many others.
anterior, posterior pituitary gland, pancreas, parathyroid gland
Structure and Synthesis of Hormones:
Steroids secreted by the ______ (cortisol and aldosterone), the ______ (estrogen and progesterone), the ______ (testosterone), and the ______ (estrogen and progesterone).
adrenal cortex, ovaries, testes, placenta
Structure and Synthesis of Hormones:
Derivatives of the amino acid tyrosine, secreted by the ______ (thyroxine and triiodothyronine) and the ______ (epinephrine and norepinephrine). There are no known polysaccharides or nucleic acid hormones.
thyroid, adrenal medullae
Storage and Synthesis of Protein and Polypeptides
Synthesis
Protein and peptide hormones are synthesized on the ______ of ______. They are first made as ______ (______), which are cleaved into ______, then processed in the ______ into active hormones and inactive fragments.
rough endoplasmic reticulum, endocrine cells, inactive precursors, preprohormones, prohormones, Golgi apparatus
Storage and Synthesis of Protein and Polypeptides
Storage
The active hormones are packaged in ______ within the cell ______, often attached to the ______, and are stored until needed.
secretory vesicles, cytoplasm, cell membrane
Storage and Synthesis of Protein and Polypeptides
Secretion
Hormone release occurs via ______ when the vesicles fuse with the ______, triggered by either increased ______ (from ______) or activation of ______. Peptide hormones are ______, allowing easy entry into the bloodstream for transport to target tissues.
exocytosis, cell membrane, cytosolic calcium, cell depolarization, cAMP-dependent protein kinases, water-soluble
Storage and Synthesis of Steroid Hormones
Synthesis
Steroid hormones are synthesized from ______, which has a similar structure (three ______ and one ______). Cholesterol for steroid synthesis comes from both ______ sources and ______ synthesis within the cells.
cholesterol, cyclohexyl rings, cyclopentyl ring, plasma, de novo
Storage and Synthesis of Steroid Hormones
Storage
Steroid hormones are not stored in ______ quantities. However, cholesterol esters are stored in ______ and can be quickly mobilized for hormone production when needed.
large, cytoplasmic vacuoles
Storage and Synthesis of Steroid Hormones
Secretion
Being highly ______, steroid hormones diffuse easily across the ______ immediately after synthesis, entering the ______ and ______ without the need for vesicle storage or transport.
lipid-soluble, cell membrane, interstitial fluid, bloodstream
Storage and Synthesis of Amine Hormones
Synthesis
Amine hormones are derived from ______. Thyroid hormones and adrenal medullary hormones (epinephrine and norepinephrine) are formed in ______.
tyrosine, glandular cells
Storage and Synthesis of Amine Hormones
Storage
Thyroid Hormones Stored in the ______ within the protein ______ in large ______.
Catecholamines (______ and ______) Stored in ______ within ______ cells.
thyroid gland, thyroglobulin, follicles, Epinephrine, Norepinephrine, vesicles, adrenal medullary
Storage and Synthesis of Amine Hormones
Secretion
Thyroid Hormones Released when split from ______; then, they bind to ______ like ______, which slowly releases them to target tissues.
Catecholamines Released from ______ in the ______ via ______. In circulation, they exist either freely or bound to other substances.
thyroglobulin, plasma proteins, thyroxine-binding globulin, vesicles, adrenal medulla, exocytosis
Hormone Secretion, Transport, and Clearance from the Blood
Secretion and Duration of Action:
Hormones vary in how quickly they act after release; some, like ______ and ______, act within seconds, while others, such as ______ and ______, may take days to months to achieve full effect.
Each hormone’s onset and duration are specialized for its function.
norepinephrine, epinephrine, thyroxine, growth hormone
Hormone Secretion, Transport, and Clearance from the Blood
Feedback Control of Secretion:
Negative Feedback: Most hormones are regulated by ______, where hormone actions or their products ______ further secretion to avoid ______.
negative feedback, suppress, overactivity
Hormone Secretion, Transport, and Clearance from the Blood
Feedback Control of Secretion:
Positive Feedback: Rarely, ______ amplifies hormone secretion, as seen in the ______ surge triggered by ______ before ovulation.
positive feedback, luteinizing hormone (LH), estrogen
Hormone Secretion, Transport, and Clearance from the Blood
Feedback Control of Secretion:
Cyclical Variations: Hormone secretion can vary with ______, ______, ______, and ______, influenced by ______.
seasonal, developmental, diurnal, sleep cycles, neural pathways
Hormone Secretion, Transport, and Clearance from the Blood
Transport in the Blood:
Water-Soluble Hormones (______ and ______): Travel dissolved in ______, freely ______ to target cells.
peptides, catecholamines, plasma, diffuse
Hormone Secretion, Transport, and Clearance from the Blood
Transport in the Blood:
Lipid-Soluble Hormones (______ and ______): Bind to ______ for transport, creating ______; they are ______ while bound and become biologically active only when ______.
steroid, thyroid hormones, plasma proteins, reservoirs, inactive, released
Hormone Secretion, Transport, and Clearance from the Blood
Hormone Clearance:
Clearance depends on both ______ and ______, known as the ______.
secretion rate, removal rate, metabolic clearance rate
Hormone Secretion, Transport, and Clearance from the Blood
Hormone Clearance:
Hormones are cleared by ______ in tissues, ______ with tissues, ______ into bile, or ______ into urine.
metabolic destruction, binding, liver excretion, kidney excretion
Hormone Secretion, Transport, and Clearance from the Blood
Hormone Clearance:
Water-Soluble Hormones are cleared ______ due to ______ and ______.
quickly, rapid degradation, kidney/liver excretion
Hormone Secretion, Transport, and Clearance from the Blood
Hormone Clearance:
Protein-Bound Hormones are cleared more ______, remaining in circulation ______; ______, for example, may stay in the blood for up to ______ days.
slowly, longer, thyroid hormones, 6
Hormone Receptors and their Activators
Hormone-Receptor Binding:
Hormones initiate action by binding to specific ______ on ______. Cells lacking these ______ do not respond to the hormone.
receptors, target cells, receptors
Hormone Receptors and their Activators
Hormone-Receptor Binding:
Hormone-receptor binding triggers a cascade of ______, allowing even ______ hormone amounts to have significant effects.
cellular reactions, small
Hormone Receptors and their Activators
Receptor Locations:
Cell Membrane: Receptors for ______, ______, and ______ hormones are on the cell membrane.
protein, peptide, catecholamine
Hormone Receptors and their Activators
Receptor Locations:
Cytoplasm: ______ hormone receptors are typically found in the cytoplasm.
Steroid
Hormone Receptors and their Activators
Receptor Locations:
Nucleus: ______ hormone receptors are located in the nucleus, often associated with ______.
Thyroid, chromosomes
Hormone Receptors and their Activators
Receptor Regulation:
The ______ and ______ of hormone receptors are not fixed; they can be adjusted by the cell as needed.
number, sensitivity
Hormone Receptors and their Activators
Receptor Regulation:
______: High hormone levels may reduce receptor numbers or activity through mechanisms like ______, ______, or ______, ______ tissue sensitivity.
Down-Regulation, inactivation, internal sequestration, lysosomal degradation, decreasing
Hormone Receptors and their Activators
Receptor Regulation:
______: Some hormones increase receptor production or signaling molecules in target cells, ______ tissue responsiveness to the hormone.
Up-Regulation, enhancing
Intracellular Signaling After Hormone Receptor Activation
Ion Channel-linked Receptors
Neurotransmitters, like ______ and ______, bind to receptors on the ______, leading to structural changes in the receptor.This binding typically results in the ______ or ______ of ______, which can allow specific ions (______, ______, ______, etc.) to move through the membrane. The altered ion movement across the membrane influences the ______ and ______ of the ______ cells, contributing to the ______. While some hormones can directly act on ______ receptors, most hormones modulate ion channels indirectly via ______ or ______ receptors.
acetylcholine, norepinephrine, postsynaptic membrane, opening, closing, ion channels, sodium, potassium, calcium, excitability, function, postsynaptic, signaling process, ion channel, G protein-linked, enzyme-linked
Intracellular Signaling After Hormone Receptor Activation
G protein-linked hormone receptors
These receptors have ______ transmembrane segments and interact with ______, which consist of three subunits: ______, ______, and ______. When a hormone (______) binds to the extracellular domain of the receptor, it induces a conformational change that activates the ______.
seven, heterotrimeric G proteins, alpha (α), beta (β), gamma (γ), ligand, G proteins
Intracellular Signaling After Hormone Receptor Activation
G protein-linked hormone receptors
Activated G proteins can initiate various intracellular responses, including:
- Opening or closing of cell membrane ion channels.
- Altering the activity of cytoplasmic enzymes.
- Activating gene transcription.
Intracellular Signaling After Hormone Receptor Activation
G protein-linked hormone receptors
In their ______ state, the G proteins bind ______. Upon ______ by the receptor, GDP is exchanged for ______, triggering downstream signaling events. When a receptor is activated, it induces a conformational change that allows the ______ to exchange ______ for ______, leading to the dissociation of the ______ subunit. This α subunit then interacts with ______ proteins to modify ______ or ______, thereby affecting cell function. The signaling is terminated when the hormone is ______, causing the α subunit to hydrolyze ______ back to ______ and reassociate with the ______ and ______ subunits to reform the ______.
inactive, guanosine diphosphate (GDP), activation, guanosine triphosphate (GTP), GDP-bound G protein, GDP, GTP, alpha (α), intracellular signaling, ion channel, enzyme activity, removed, GTP, GDP, beta (β), gamma (γ), inactive G protein complex
Intracellular Signaling After Hormone Receptor Activation
Enzyme-linked hormone receptors are membrane proteins that typically span the membrane ______, with ______ on the outside and ______ on the inside. When a hormone binds to the receptor, it ______ an enzyme located just ______ the ______, leading to changes in cellular function. While some enzyme-linked receptors possess ______, others depend on ______ to facilitate these cellular changes.
once, hormone-binding sites, catalytic sites, activates, inside, membrane, intrinsic enzymatic activity, associated enzymes
Second Messenger Mechanisms:
- Adenylyl Cyclase-cAMP Second Messenger System
- Cell Membrane Phospholipid Second Messenger System
- Calcium-Calmodulin Second Messenger System
Second Messenger Mechanisms:
Adenylyl Cyclase-cAMP Second Messenger System
The coupling of a hormone with its receptor allows activation of ______. If the receptor couples with a ______ (Gs protein), this stimulates ______, an enzyme that converts cytoplasmic ______ into ______. cAMP then activates ______, which phosphorylates specific cell proteins, triggering a cascade of ______ leading to the cell’s ______ to the hormone.
G proteins, stimulatory G protein, adenylyl cyclase, ATP, cAMP, cAMP-dependent protein kinase, biochemical reactions, response
Second Messenger Mechanisms:
Adenylyl Cyclase-cAMP Second Messenger System
When the hormone receptor is coupled with an ______ (Gi protein), adenylyl cyclase activity ______, reducing ______ and leading to an ______ effect in the cell. Whether cAMP levels rise or fall, different types of target cells can have varying responses depending on their specific ______ and ______.
inhibitory G protein, decreases, cAMP levels, inhibitory, enzymes, intracellular pathways
Second Messenger Mechanisms:
Adenylyl Cyclase-cAMP Second Messenger System
When a hormone binds to its receptor, it can activate a ______ (Gs protein), which in turn activates ______, converting ______ into ______ within the cell. This cAMP acts as a ______, initiating a cascade that activates ______. This kinase phosphorylates specific proteins, ultimately triggering a range of ______. This process amplifies the hormone’s ______, enabling even ______ hormone levels to produce significant effects, similar to other pathways involving ______ and ______ receptors.
stimulatory G protein, adenylyl cyclase, ATP, cAMP, second messenger, cAMP-dependent protein kinase, cellular responses, signal, low, G protein-coupled, enzyme-linked
Second Messenger Mechanisms:
Adenylyl Cyclase-cAMP Second Messenger System
HORMONES THAT USE ADENYLYL CYCLASE:
- Adrenocorticotropic hormone (ACTH)
- Angiotensin II (epithelial cells)
- Calcitonin
- Catecholamines (beta receptors)
- Corticotropin-releasing hormone (CRH)
- Follicle-stimulating hormone (FSH)
- Glucagon
- Growth hormone-releasing hormone (GHRH)
- Human chorionic gonadotropin (hCG)
- Luteinizing hormone (LH)
- Parathyroid hormone (PTH)
- Secretin
- Somatostatin
- Thyroid-stimulating hormone (TSH)
- Vasopressin (V2 receptor, epithelial cells)
Second Messenger Mechanisms:
Cell Membrane Phospholipid Second Messenger System
Some hormones activate receptors linked to the enzyme ______, located inside the ______. This enzyme breaks down ______, especially ______, into two important second messengers: ______ and ______.
phospholipase C, cell membrane, membrane phospholipids, phosphatidylinositol bisphosphate (PIP₂), inositol triphosphate (IP₃), diacylglycerol (DAG)
Second Messenger Mechanisms:
Cell Membrane Phospholipid Second Messenger System
IP₃ triggers the release of ______ from cellular stores, like the ______ and ______. The released calcium acts as a ______ to initiate ______.
calcium ions, endoplasmic reticulum, mitochondria, secondary messenger, cellular responses
Second Messenger Mechanisms:
Cell Membrane Phospholipid Second Messenger System
DAG activates ______, an enzyme that phosphorylates various proteins to drive the cell’s ______. DAG also includes ______, a precursor for prostaglandins and other local hormones that regulate numerous tissue functions across the body.
protein kinase C, response, arachidonic acid
Second Messenger Mechanisms:
Cell Membrane Phospholipid Second Messenger System
HORMONES THAT USE THE PHOSPHOLIPID SECOND MESSENGER SYSTEM:
- Angiotensin II (vascular smooth muscle)
- Catecholamines (a receptors)
- Gonadotropin-releasing hormone (GnRH)
- Growth hormone-releasing hormone (GHRH)
- Parathyroid hormone (PTH)
- Oxytocin
- Thyrotropin-releasing hormone (TRH)
- Vasopressin (V1 receptor, vascular smooth muscle)
Second Messenger Mechanisms:
Calcium-Calmodulin Second Messenger System
Calcium entry into cells is triggered by either changes in ______ or by hormones that open ______.
membrane potential, calcium channels
Second Messenger Mechanisms:
Calcium-Calmodulin Second Messenger System
Once inside the cell, calcium binds to ______, a protein with ______ calcium-binding sites. When three or four sites are occupied, calmodulin changes ______, activating or inhibiting ______ that modify cell functions.
calmodulin, four, shape, protein kinases
Second Messenger Mechanisms:
Calcium-Calmodulin Second Messenger System
For calmodulin activation, ______ must increase from the normal ______ to around ______ to ______, similar to the calcium increase required to activate ______ in muscle contraction.
calcium concentration, 10⁻⁷ mol/L, 10⁻⁶, 10⁻⁵ mol/L, troponin C
HORMONES THAT ACT MAINLY ON THE GENETIC MACHINERY OF THE CELL
Steroid hormones act primarily by increasing ______ within target cells.
protein synthesis
HORMONES THAT ACT MAINLY ON THE GENETIC MACHINERY OF THE CELL
Steroid hormones act primarily by increasing protein synthesis within target cells.
- The process begins as the steroid hormone diffuses into the ______ and binds to a specific ______ in the ______. This hormone-receptor complex then enters the ______, binding to ______ at specific sites and activating ______ to form ______.
cell, receptor protein, cytoplasm, nucleus, DNA, transcription, mRNA
HORMONES THAT ACT MAINLY ON THE GENETIC MACHINERY OF THE CELL
Steroid hormones act primarily by increasing protein synthesis within target cells.
- The mRNA moves to the ______, directing ______ to synthesize new proteins that function in various cellular roles.
cytoplasm, ribosomes
HORMONES THAT ACT MAINLY ON THE GENETIC MACHINERY OF THE CELL
Steroid hormones act primarily by increasing protein synthesis within target cells.
- For example, aldosterone binds to receptors in ______ cells, triggering the synthesis of ______ that promote ______ and ______. This process takes at least ______ minutes, highlighting the delayed action typical of steroid hormones.
kidney, proteins, sodium reabsorption, potassium secretion, 45
HORMONES THAT ACT MAINLY ON THE GENETIC MACHINERY OF THE CELL
Thyroid Hormones Increase ______ in the Cell ______
Gene Transcription, Nucleus
HORMONES THAT ACT MAINLY ON THE GENETIC MACHINERY OF THE CELL
Thyroid Hormones Increase Gene Transcription in the Cell Nucleus
Thyroid hormones, ______ and ______, increase ______ of specific genes by binding ______ to receptor proteins within the cell ______.
These nuclear receptors act as ______, promoting the synthesis of numerous ______ (likely ______ or more), many of which are enzymes that boost ______ in almost all body cells.
Notably, once bound, thyroid hormones can exert their effects for extended periods, lasting ______ to ______, due to their sustained action on gene expression.
thyroxine (T4), triiodothyronine (T3), transcription, directly, nucleus, transcription factors, intracellular proteins, 100, metabolic activity, days, weeks
Thyroid Metabolic Hormones
Thyroid Gland
Located below the ______ near the ______, is one of the ______ endocrine glands (______-______ grams in adults).
larynx, trachea, largest, 15, 20
Thyroid Metabolic Hormones
Thyroid Gland
It secretes two primary metabolic hormones: ______ and ______, which increase the body’s ______. A lack of these hormones can lower the ______ by ______-______%, while an excess can increase it by ______-______%.
thyroxine (T4), triiodothyronine (T3), metabolic rate, basal metabolic rate, 40, 50, 60, 100
Thyroid Metabolic Hormones
Thyroid Gland
Thyroid secretion is mainly regulated by ______ from the ______.
thyroid-stimulating hormone (TSH), anterior pituitary gland
Thyroid Metabolic Hormones
Hormone Production:
About 93% of thyroid hormone output is ______, with the remaining 7% as ______. Most T4 is later converted to ______ in tissues, making both essential for metabolic regulation.
T4, T3, T3
Thyroid Metabolic Hormones
Hormone Production:
T3 is approximately ______ times more potent than ______ but is present in ______ quantities and has a ______ duration in the bloodstream.
four, T4, smaller, shorter
Physiologic Anatomy of the Thyroid Gland
The thyroid gland consists of numerous ______ (______–______ micrometers in diameter) filled with ______, a substance mainly composed of ______, a glycoprotein that stores thyroid hormones. Follicles are lined with ______ cells that secrete hormones into the follicles.
closed follicles, 100, 300, colloid, thyroglobulin, cuboidal epithelial
