Hormones Regulating Glucose, Calcium and Sleep

Calcitonin

Hormone from the thyroid that DECREASES blood calcium.

Parathyroid Hormone (PTH)

Hormone from the parathyroid glands that INCREASES blood calcium.

Calcitonin vs PTH

Calcitonin lowers blood calcium; PTH raises blood calcium.

Calcitonin Effect on Bone

Decreases osteoclast activity and increases osteoblast activity, storing calcium in bone.

(Calcitonin → osteoclasts ↓ → blood Ca²⁺ ↓)

PTH Effect on Bone

Increases osteoclast activity, releasing calcium from bone into the blood.

(PTH → osteoclasts ↑ → blood Ca²⁺ ↑)

PTH and Vitamin D

stimulates vitamin D production, which increases calcium absorption in the intestine.

What makes up the Parathyroid Glands?

Four small glands behind the thyroid that regulate blood calcium.

Insulin

Hormone from pancreatic beta cells that DECREASES blood glucose.

Glucagon

Hormone from pancreatic alpha cells that INCREASES blood glucose.

Insulin vs Glucagon

Insulin lowers blood glucose; glucagon raises blood glucose.

Insulin Release

Released when blood glucose is HIGH.

Glucagon Release

Released when blood glucose is LOW.

Alpha Cells

Produce glucagon.

Beta Cells

Produce insulin.

Delta Cells

Produce somatostatin.

Somatostatin

Inhibits the release of insulin and glucagon.

Pancreas

Produces hormones that regulate blood glucose and digestive enzymes.

Cortisol

Hormone from the adrenal cortex that INCREASES blood glucose.

Gluconeogenesis

Production of glucose from non-carbohydrate substances.

Glycogenolysis

Breakdown of glycogen into glucose, increasing blood glucose.

What makes up the Pineal Gland?

Small gland in the brain that produces melatonin.

Melatonin

A hormone that is secreted by the pineal gland helps regulate the sleep-wake cycle

Melatonin and Light

Melatonin increases when light decreases.

Thymus Gland

Produces T cells that are important for the immune system.

Negative Feedback

Mechanism that helps keep hormone levels and body conditions within a normal range.

High Blood Calcium

Triggers calcitonin release.

(High Ca²⁺ → Calcitonin → lowers blood calcium ⬇)

Low Blood Calcium

Triggers PTH (parathyroid hormone) release.

High Blood Glucose

Triggers insulin release.

(High blood glucose → insulin released → blood glucose decreases ⬇)

Low Blood Glucose

Triggers glucagon release.

(Low blood glucose → glucagon released → blood glucose increases ⬆)