Endocrine A&P Thyroid, Parathyroid,
Thymus, and Pineal Glands Practice
Exam Question and Answers Latest
Updates 2026 Graded A+
What type of form is T3?
biologically active
How does T3 bind with thyroid hormone receptors?
with high affinity to exert physiologic effects
How is rT3 produced?
5'-deiodination of T4
What physiological function does rT3 serve?
none
When do rT3 levels rise? (3)
1. stress
2. illness
3. starvation
What is 99% of T3/T4 bound by? (3)
1. thyroxine-binding globulins (TBGs)
2. albumin
3. other plasma proteins
What happens when serum free T3/T4 decline?
bound T3/T4 released from plasma protein
Which thyroid hormone is more potent?
T3
5 functions of thyroid hormones (mainly T3)
1. metabolic regulation
2. cardiovascular effects
3. growth and development
4. nervous system
, 5. GI and musculoskeletal systems
Metabolic regulation: What do thyroid hormones increase? (4)
1. basal metabolic rate
2. glucose absorption
3. lipolysis
4. protein turnover
Cardiovascular effects: What do thyroid hormones increase? (2)
1. heat rate
2. cardiac output
Growth and development: What are thyroid hormones crucial for? (2)
1. fetal brain development
2. linear bone growth
Growth and development: What does deficiency of thyroid hormones
during pregnancy or early childhood lead to?
cretinism
Nervous system: Effects of thyroid hormone (2)
1. enhances alertness, reflexes, and coordination
2. affects mood and cognition
GI and musculoskeletal systems: What do thyroid hormones
increase? (2)
1. GI motility
2. muscle protein turnover
Clinical relevance: Which hormone is commonly measured to assess
thyroid output?
T4
Clinical relevance: Which hormone is commonly measured to assess
tissue-level thyroid activity?
T3
Clinical relevance: Which hormone is most sensitive marker of
thyroid axis activity?
TSH
What is calcium essential for? (4)
1. muscle contraction
2. neuronal excitability
3. blood clotting
Thymus, and Pineal Glands Practice
Exam Question and Answers Latest
Updates 2026 Graded A+
What type of form is T3?
biologically active
How does T3 bind with thyroid hormone receptors?
with high affinity to exert physiologic effects
How is rT3 produced?
5'-deiodination of T4
What physiological function does rT3 serve?
none
When do rT3 levels rise? (3)
1. stress
2. illness
3. starvation
What is 99% of T3/T4 bound by? (3)
1. thyroxine-binding globulins (TBGs)
2. albumin
3. other plasma proteins
What happens when serum free T3/T4 decline?
bound T3/T4 released from plasma protein
Which thyroid hormone is more potent?
T3
5 functions of thyroid hormones (mainly T3)
1. metabolic regulation
2. cardiovascular effects
3. growth and development
4. nervous system
, 5. GI and musculoskeletal systems
Metabolic regulation: What do thyroid hormones increase? (4)
1. basal metabolic rate
2. glucose absorption
3. lipolysis
4. protein turnover
Cardiovascular effects: What do thyroid hormones increase? (2)
1. heat rate
2. cardiac output
Growth and development: What are thyroid hormones crucial for? (2)
1. fetal brain development
2. linear bone growth
Growth and development: What does deficiency of thyroid hormones
during pregnancy or early childhood lead to?
cretinism
Nervous system: Effects of thyroid hormone (2)
1. enhances alertness, reflexes, and coordination
2. affects mood and cognition
GI and musculoskeletal systems: What do thyroid hormones
increase? (2)
1. GI motility
2. muscle protein turnover
Clinical relevance: Which hormone is commonly measured to assess
thyroid output?
T4
Clinical relevance: Which hormone is commonly measured to assess
tissue-level thyroid activity?
T3
Clinical relevance: Which hormone is most sensitive marker of
thyroid axis activity?
TSH
What is calcium essential for? (4)
1. muscle contraction
2. neuronal excitability
3. blood clotting
