M3: The Thyroid Gland Flashcards
Small, butterfly-shaped gland that can be found at the front of a person’s neck
Thyroid gland
Often converted to T4 in the body
T3 (Triiodothyronine)
- In charge of the cellular conversion of glucose to ATP
- Increase in T4 also increases BMR (Basal metabolic rate)
T4 (Thyroxine)
- Aids in calcium regulation & calcium homeostasis
- Secreted by the C-cells of the thyroid
Calcitonin
- Secreted only when thyroid-stimulating hormone is present
- Secreted by the thyroid follicle cells (thyrocytes)
- Regulates energy use and energy storage
- Both play a part in the BMR
- Determines how fast and efficiently a person utilizes energy
Thyroid hormone
Refers to the rate of energy usage when the body is quiet
Basal metabolic rate
The thyroid helps regulate calcium levels through ___________.
Calcitonin
Calcitonin increases bone mass by stimulating ___________ to absorb calcium and inhibiting ____________ from breaking down bones.
Osteoblasts
High blood calcium triggers calcitonin release, while low blood calcium suppresses it
Feedback system
- Occurs when the thyroid produces insufficient T3 and T4 hormones
Hypothyroidism
(Present at birth) can cause intellectual disabilities and stunted bone growth if not treated early
Congenital hypothyroidism
Results when the thyroid works normally at birth but fails to secrete enough hormones in adult life
Myxedema
This condition is more prevalent in females than males
Myxedema
This condition leads to the following symptoms:
- Slow heart rate, low body temperature
- Dry hair and skin, muscle weakness, fatigue
- Weight gain tendency
Myxedema
Congenital hypothyroidism and myxedema can be managed with the treatment called ______ ____________ ____________________ __________.
Oral hormone replacement therapy
- Also known as overactive thyroid, occurs when the thyroid gland produces excess hormones, speeding up metabolism by around 60-100% above normal
Hyperthyroidism
Fluid buildup behind the eyes, causing them to bulge
Exophthalmos
Affects more females than males. If untreated, can cause eyelids to remain open during sleep, leading to a corneal damage
Graves’ disease
The treatment for Graves’ disease is ________ ____________ _________ and ________________ ___________ ___________ which destroys thyroid tissue to reduce hormone levels.
Partial thyroid removal; radioactive iodine therapy
Also develops when iodine deficiency prevents the thyroid from producing complete T3 and T4 hormones. This leads to excess TSH production, causing thyroid enlargement.
Goiter
