OIA1004 (TERMS) ENDOCRINE SYSTEM

Hormones

Chemical mediators regulating activities of distant cells.

Endocrine Glands

Secrete hormones directly into the bloodstream.

Exocrine Glands

Secrete products into ducts or body cavities.

Hypothalamus

Regulates pituitary gland hormone release.

Pituitary Gland

Master gland controlling other endocrine glands.

Thyroid Gland

Regulates metabolism through thyroid hormones.

Parathyroid Glands

Regulate calcium levels in the blood.

Adrenal Glands

Produce hormones for stress response and metabolism.

Pancreatic Islets

Secrete insulin and glucagon for blood sugar control.

Local Hormones

Act on neighboring cells (paracrine signaling).

Circulating Hormones

Travel through blood to distant target cells.

Lipid-Soluble Hormones

Require transport proteins to circulate in blood.

Water-Soluble Hormones

Circulate freely in blood plasma.

Steroid Hormones

Include aldosterone, cortisol, androgens, and sex hormones.

Thyroid Hormones

Include T3 and T4, regulate metabolism.

Amine Hormones

Derived from amino acids, e.g., adrenaline.

Peptide Hormones

Include insulin, glucagon, and pituitary hormones.

Autocrine Signaling

Hormones act on the same cell that secretes them.

Receptor Binding

Hormones bind to specific receptors on target cells.

Transport Proteins

Carry lipid-soluble hormones in the bloodstream.

Hormone Action Mechanism

Hormones trigger responses in target cells.

Hormone Regulation

Controlled by feedback mechanisms in the body.

Eicosanoid

Signaling molecules like prostaglandins and leukotrienes.

Target cell specificity

Hormones influence specific cells via receptors.

Protein receptors

Bind hormones to initiate cellular responses.

Lipid-soluble hormones

Hormones that penetrate target cell membranes.

Water-soluble hormones

Hormones that bind to membrane receptors.

Intracellular receptors

Receptors located inside target cells for lipid hormones.

Direct gene activation

Process where hormones trigger gene expression directly.

Second messenger systems

Mediators that relay signals from membrane receptors.

Cyclic AMP (cAMP)

A second messenger involved in signaling pathways.

Cyclic GMP (cGMP)

Another second messenger in cellular signaling.

PIP2 (phosphatidyl inositol bisphosphate)

A membrane phospholipid involved in signaling.

Hormone responsiveness

Cell's reaction depends on hormone concentration and receptors.

Permissive effect

One hormone requires another for full effect.

Synergistic effect

Combined hormone effects exceed individual effects.

Antagonistic effect

One hormone opposes the action of another.

Cyclic AMP signaling mechanism

Uses cAMP to transmit hormone signals.

PIP-calcium signal mechanism

Involves calcium ions as secondary messengers.

Hormone concentration

Amount of hormone affecting target cell response.

Number of hormone receptors

Influences target cell sensitivity to hormones.

Hypothalamus-pituitary interaction

Hypothalamus regulates pituitary hormone release.

Glucagon

Hormone that raises blood glucose levels.

Insulin

Hormone that lowers blood glucose levels.

Antagonistic Effect

Opposing actions of glucagon and insulin.

Humoral Stimuli

Hormone release triggered by blood chemical changes.

Neural Stimuli

Hormone release stimulated by nerve signals.

Hormonal Stimuli

Hormone release in response to other hormones.

Negative Feedback

System where hormone levels regulate their own production.

Positive Feedback

System where hormone levels amplify their own production.

Oxytocin

Hormone that induces uterine contractions during childbirth.

Parathyroid Hormone (PTH)

Hormone that increases blood calcium levels.

Corticotropin-releasing hormone (CRF)

Hormone from hypothalamus stimulating ACTH release.

Growth Hormone-Releasing Hormone (GRF)

Stimulates release of growth hormone from pituitary.

Thyroid-Stimulating Hormone (TSH)

Stimulates thyroid gland to produce thyroid hormones.

Adrenocorticotropic Hormone (ACTH)

Stimulates adrenal cortex to release cortisol.

Follicle-Stimulating Hormone (FSH)

Regulates reproductive processes in gonads.

Luteinizing Hormone (LH)

Triggers ovulation and testosterone production.

Thyroid Hormones (T3, T4)

Regulate metabolism and energy production.

Melatonin

Hormone regulating sleep-wake cycles.

Testosterone

Primary male sex hormone affecting development.

Estrogen

Primary female sex hormone influencing reproductive system.

Follicle-stimulating hormone

Stimulates gonadal function and gamete production.

Hypothalamus

Links nervous and endocrine systems, regulates pituitary.

Pituitary gland

Master gland controlling hormone release in body.

Anterior pituitary

Granular tissue secreting various hormones.

Posterior pituitary

Neural tissue storing and releasing hormones.

Hypophyseal portal system

Carries hypothalamic hormones to anterior pituitary.

Neurosecretory cells

Synthesize hormones like oxytocin and ADH.

Oxytocin

Hormone involved in childbirth and lactation.

Antidiuretic hormone (ADH)

Regulates water balance in the body.

Somatotrophs

Anterior pituitary cells secreting growth hormone.

Thyrotrophs

Secrete thyroid-stimulating hormone (TSH).

Gonadotrophs

Secrete follicle-stimulating and luteinizing hormones.

Lactotrophs

Secrete prolactin for milk production.

Corticotrophs

Secrete adrenocorticotropic hormone (ACTH).

Growth hormone (GH)

Stimulates growth and metabolism in tissues.

Thyroid-stimulating hormone (TSH)

Stimulates thyroid gland to produce hormones.

Prolactin

Promotes milk production in mammary glands.

Adrenocorticotropic hormone (ACTH)

Stimulates adrenal cortex to produce cortisol.

Negative feedback

Regulates hormone levels by inhibiting secretion.

Insulin-like growth factors (IGFs)

Mediators of growth hormone effects.

Hypertrophy

Increase in cell size due to growth.

Hyperplasia

Increase in cell number due to division.

Lipolysis

Breakdown of fats in adipose tissue.

Gluconeogenesis

Formation of glucose from non-carbohydrates in liver.

Amino Acid Uptake

Cellular absorption of amino acids for protein synthesis.

Insulin-like Growth Factors (IGFs)

Hormones promoting growth, secreted by liver.

Osteoblasts

Cells responsible for bone formation.

Osteoclasts

Cells responsible for bone resorption.

Chondrocytes

Cartilage cells involved in bone length growth.

Epiphyseal Growth Plate

Cartilage area where bone length increases.

Oxytocin

Hormone stimulating uterine contractions during childbirth.

Milk Ejection Reflex

Release of milk from mammary glands during suckling.

Antidiuretic Hormone (ADH)

Hormone conserving water by reducing urine output.

Aquaporin-2 Channels

Water channels facilitating kidney water reabsorption.

Hypersecretion

Excess hormone production leading to abnormal growth.

Hyposecretion

Insufficient hormone production causing growth issues.

Gigantism

Excessive growth due to hGH hypersecretion in children.

Acromegaly

Bone enlargement due to hGH hypersecretion in adults.