15.7-10 Chapter Human Structure and Function

Location of thyroid gland

In anterior neck on trachea, inferior to larynx

two groups of hormones produced by the thyroid gland

Thyroxine (T₄), Triiodothyronine(T₃)

Thyroxine (T₄)

Major hormone secreted by thyroid follicles

Triiodothyronine(T₃)

Formed at target tissues by conversion of T₄  to T₃

Effects of thyroid hormones(TH)

Increases metabolism and body temperature, regulates growth and development, maintains BP

Location of parathyroid glands

Hidden from view in posterior part of thyroid glands

general functions of parathyroid hormone (PTH)

PTH controls calcium balance in the blood, Stimulates osteoclasts, enhances calcium reabsorption by the kidneys, and promotes activation of vitamin D

Location of adrenal glands

perched on kidneys, enclosed in fibrous capsule and cushion of fat

Two glands in adrenal glands

Adrenal medulla, Adrenal cortex

Adrenal medulla

inner, made of nervous tissue, part of sympathetic nervous system

Adrenal cortex

outer, encapsulates medulla and forming bulk of gland

glucocorticoids

Influence the energy of metabolism of most body cells

Cortisol

primary glucocorticoid secreted in humans, enhances the sympathetic nervous system’s vasoconstrictive effects helping to maintain blood pressure

How is cortisol secretion regulated?

Negative feedback mechanism regulates glucocorticoid secretion, Cortisol release is promoted by ACTH

Location of pineal gland

hangs from roof of third ventricle in diencephalon 

Function of pineal gland

secretes melatonin which makes us drowsy