Untitled Flashcard Set

What leads to physiological responses in other cells in the endocrine system?

Outgoing signals.

What is signal transduction?

The conversion of an impulse or stimulus into another physical or chemical form, affecting cell behavior.

Where are cell-surface receptors located?

In the plasma membrane.

What type of molecules do intracellular receptors bind?

Small, hydrophobic signal molecules.

What characterizes fast signaling?

Involves altered protein functions and responds within seconds to minutes.

What is the main feature of slow signaling?

Involves changes in gene expression, taking minutes to hours.

What does testosterone influence in the body?

Physiological behavior and anatomy.

How do signals act over varying distances in the body?

They can act either long-range or short-range.

What type of hormones are transported by the bloodstream continuously?

Hormones.

What are paracrines?

Local hormones secreted to nearby cells affecting local tissue functions.

What is the primary function of neurotransmitters?

Facilitate rapid communication between nerve cells.

How do exocrine glands secrete their products?

Through ducts onto epithelial surfaces.

What distinguishes endocrine glands from exocrine glands?

Endocrine glands secrete hormones directly into the blood without ducts.

What type of cells are neuroendocrine cells?

Hybrid cells with features of both neurons and endocrine cells.

What is endocrinology?

The study of the endocrine system and associated disorders.

How many hormones does the hypothalamus produce?

Eight hormones.

What do releasing hormones do?

Stimulate hormone release from the anterior pituitary.

Which hormone inhibits the anterior pituitary's function?

Inhibiting hormones such as somatostatin.

What is the function of follicle-stimulating hormone (FSH)?

Stimulates follicle development and sperm production.

How does luteinizing hormone (LH) affect the body?

Stimulates ovulation and testosterone secretion.

What does thyroid-stimulating hormone (TSH) regulate?

Growth and secretion of thyroid hormones.

What is the primary function of adrenocorticotropic hormone (ACTH)?

Increases secretion of glucocorticoids.

What is the role of prolactin (PRL)?

Stimulates milk production in mammary glands.

What does growth hormone (GH) promote?

Growth and mitosis throughout the body.

What does antidiuretic hormone (ADH) regulate?

Concentration of urine and conservation of water.

What is oxytocin's role during childbirth?

Stimulates contractions and milk ejection.

How is hormone production regulated in the body?

By negative feedback from target organs.

What organs are part of the endocrine system?

Thyroid, parathyroid, adrenal glands, pancreas, and gonads.

How does the thyroid gland manage the basal metabolic rate?

Through TRH secretion from the hypothalamus.

What do follicular cells in the thyroid gland secrete?

Thyroid hormones (TH) in response to TSH.

What hormone do parathyroid glands secrete when blood calcium levels are low?

Parathyroid hormone (PTH).

What does the adrenal medulla respond to during stress?

Stimulates release of epinephrine and norepinephrine.

What type of cells in the pancreas secrete glucagon?

Alpha cells.

What do beta cells in the pancreas secrete?

Insulin.

What do ovaries produce?

Estrogen and progesterone.

What type of hormones do testes produce?

Testosterone.

Name the three chemical classes of hormones.

Steroids, monoamines, and peptides.

What are steroid hormones derived from?

Cholesterol.

What amino acid is dopamine synthesized from?

Tyrosine.

What defines peptide hormones?

Composed of 3 to 200+ amino acids.

What are the steps to synthesize peptides?

Transcription, translation, folding, and modification.

How do hormones follow secretion rhythms?

Daily (circadian), monthly, or physiological stimuli triggered.

What are neural stimuli?

Nerve fibers stimulating hormone release.

What triggers hormonal stimuli?

Other hormones.

What are humoral stimuli?

Blood-borne stimuli like changes in calcium levels.

What characterizes short-term stress responses?

Involves catecholamines from the adrenal medulla.

What effects are seen with short-term stress responses?

Increased heart rate and blood pressure.

What initiates long-term stress responses?

Corticotropin-releasing hormone (CRH) from the hypothalamus.

What does long-term stress response lead to?

Retention of sodium and water by kidneys.

What is metabolic clearance rate (MCR)?

Rate at which hormones are removed from the blood.

What happens to the number of receptors during up-regulation?

It increases, enhancing sensitivity to hormones.

What does down-regulation involve?

Decreasing the number of receptors.

How do hormones interact in permissive effects?

One hormone enhances the target organ’s response to another hormone.

What are antagonistic effects?

One hormone opposes the action of another.

What primarily breaks down hormones?

Liver and kidneys.

What condition is characterized by hypersecretion of growth hormone during childhood?

Gigantism.

What results from hyposecretion of growth hormone during childhood?

Pituitary dwarfism.

What hormone deficiency leads to hypothyroidism?

Lack of dietary iodine.

What is a common outcome of Cushing syndrome?

Excessive cortisol secretion.

What defines type I diabetes?

Very low levels of insulin.

What is the primary issue in type II diabetes?

Insulin resistance.

What type of stress does the adrenal medulla respond to?

Short-term stress.

What do hormones do in the endocrine system?

Influence various bodily functions.

What type of effects can hormones produce?

They can produce various cell behaviors.

What happens during the stress response related to cortisol?

ACTH stimulates cortisol release from adrenal glands.

How is oxytocin's action described during childbirth?

It promotes contractions.

What does insulin do in the body?

Lowers blood glucose levels.

What is the function of glucagon?

Raises blood glucose levels.

How does the hormone TRH affect the pituitary gland?

Stimulates TSH secretion.

What secretion does the hypothalamus regulate?

Various hormones for the pituitary gland.

What is the action of calmodulin in muscle contractions?

It interacts with calcium to facilitate contractions.

What metabolic effects do cortisol trigger?

Converts proteins and fats into glucose for energy.

What type of hormone requires transport proteins to travel in blood?

Lipid-soluble hormones.

How do peptide hormones primarily act?

Through second messenger systems.

What does the mechanism of DAG primarily amplify?

Regulatory pathways via kinase activation.

What does increased intracellular Ca²⁺ from IP3 typically lead to?

Activation of enzymes modifying cell functionality.

What characterizes the hydrophilic nature of peptides?

Incapable of passing through the plasma membrane.

What is a common characteristic of steroid hormones?

They can diffuse through the plasma membrane.

What modifies mRNA to produce proteins?

Hormone binding to its receptor.

What condition is linked with elevated blood glucose and muscle loss?

Cushing syndrome.

What leads to excessive thirst in diabetes?

Hyperglycemia.

What is the primary regulator of blood calcium levels?

Parathyroid hormone (PTH).

Which hormone does ACTH stimulate secretion of?

Cortisol.

What are the physiological changes triggered by epinephrine during stress?

Increased heart rate and blood pressure.

What is the key role of oxytocin in lactation?

Stimulates milk ejection.

What hormone serves to suppress hormone production by the anterior pituitary?

Somatostatin.

What is a typical effect of prolonged exposure to insulin on receptors?

Down-regulation.

Where does the inhibition of thyroid hormone production primarily occur?

Due to lack of iodine.

What initiates the release of hormones in the endocrine system?

Physiological stimuli.

What type of hormones are derived from cholesterol?

Steroid hormones.

What happens to hormone levels during acute stress responses?

They typically rise.

How can the secretion of glucagon affect blood glucose levels?

It raises blood glucose levels.

What is the hormonal response to dehydration?

Release of ADH to conserve water.

How do hormones exert their action on target cells?

By binding to specific receptors.

What type of mechanism is primarily used by lipid-soluble hormones?

Gene activation pathways.

What happens to hormone receptors during up-regulation?

Increased receptor numbers boost sensitivity.

What main effect does growth hormone (GH) have on the body?

Promotes growth and cell division.

What is the general function of thyroid hormones?

Regulate metabolism.

Which pituitary hormone stimulates milk production?

Prolactin (PRL).

What hormone's role involves increasing reabsorption of water?

Antidiuretic hormone (ADH).