endocrinology Ⅱ pituitary gland. thyroid gland the thyroid hormones synthesis and secretion:...

ENDOCRINOLOGY Ⅱ

Pituitary Gland

Thyroid gland

Thyroid gland

The thyroid hormones Synthesis and secretion: epithelioid cells Storage: in colloid ,a large glycoprotein (thyrog

lobulin).

The thyroid hormones

The thyroid hormones

: combine with iodine

: 1mg/week

The thyroid hormones

The thyroid hormones

The thyroid hormones

When the synthesis of TH ceases, Physiologic effects of deficiency are not observed for 2-3 months

The thyroid hormones (TH)

The thyroid hormones

The thyroid hormones (TH)

Cretinism TH stimulation formation of dendrites,

axons, myelin and neuroglia Deficiency in iodine in fetus : TH↓→

Cretinism Treatment : supplement the TH within three

months after birth

The thyroid hormones (TH)

The thyroid hormones (TH)

The thyroid hormones (TH)

The thyroid hormones (TH)

Lengthy sleep

Nonpitting edema

The thyroid hormones (TH)

The thyroid hormones (TH)

Increase the appetite

:TH↓→constipation

HyperthyroidismHyperthyroidism

Major clinical signs ：include weight loss (often accompanied by an increased appetite),anxiety, intolerance to heat, hair loss, muscle aches, weakness, fatigue, hyperactivity, irritability

The thyroid hormones (TH)

Regulation of Thyroid Hormone Secretion

Hypothalamic Pituitary Thyroid Axis Autoregulation

Regulation of Thyroid Hormone Secretion

Hypothalamic Pituitary Thyroid Axis

Cold, etc.

TRHhypothalamus

TSHAnterior pituitary

T3,T4

Target cell

Thyroid gland

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Regulation of Thyroid Hormone Secretion

Mechanism of goiter Iodine↓→T3,T4↓→

TSH↑ (negative feedback) →

T3,T4 ↑and thyroid cells ↑ →goiter

The thyroid hormones (TH)

Regulation of Thyroid Hormone Secretion

Auto regulation Wolff-chaikoff effect

Without control of TSH, the thyroid gland can adapt itself function to iodide uptake

Iodide concentration: 10mmol/L , no uptake of iodide

Regulation of Thyroid Hormone Secretion

Effect of Autonomic Nervous System on Thyroid Activity Sympathetic nerve: formation of TH↑ Para sympathetic nerve: formation of TH↓

Abnormality of thyroid gland Hypothyroidism

Cretinism: extreme hypothyroidism during fetal life, infancy, or childhood

Goiter Myxedema: bagginess under the eyes and swelling of

the face develop atherosclerosis Sleeping up to 12 to 14 hours a day, extreme muscular sluggishness heart rate↓ cardiac output↓ blood volume↓ Body Weight↑ Constipation mental sluggishness

Abnormality of thyroid gland Hyperthyroidism

high state of excitability intolerance to heat increased sweating mild to extreme weight loss varying degrees of diarrhea muscle weakness nervousness or other psychic disorders Extreme fatigue but inability to sleep tremor of the hands

Summary

thyroid hormones Function Abnormality regulation