anatomy endocrine system flashcards exam 3

What is a endocrine gland

A ductless gland that secretes hormones directly into the blood stream to regulate body processes

List the major endocrine glands

Pituitary, hypothalamus, thyroid, parathyroid’s, adrenal gland, pancreas, thymus, and gonads (testes and ovaries)

What is a hormone

A chemical messenger secreted by endocrine glands that travels through the blood to target specific cells

Name some processes regulated by hormones

Growth, metabolism, reproduction, blood sugar regulation, stress response, and calcium balance

How is the endocrine system similar to the nervous system

Both coordinate and regulate body functions and maintain homeostasis, though the endocrine system acts more slowly and uses chemical messengers (hormones)

How are hormones classified by structure

As amino acid based hormones or steroid hormones

What is a target cell

A cell that has receptors for a specific hormone and responds to its signal

What are the three mechanism that control hormone secretion

Humoral - blood levels of ions and nutrients

Neural - nerve stimulation

Hormonal - hormone triggers another hormone

Where is the pituitary gland located

At the base of the brain, in the sella turcica of the sphenoid bone

Name the hormones secreted by the anterior pituitary and their targets

GH- bones and muscles

TSH- thyroid

ACTH- adrenal cortex

FSH and LH- gonads

PRL- mammary glands

MSH- melanocytes

Name hormones secreted by the posterior pituitary and their targets

ADH- kidneys (water reabsorption)

Oxytocin- uterus (contractions) and mammary glands (milk ejection)

How does the hypothalamus control the anterior pituitary

Through releasing and inhibiting hormones via the hypophyseal portal system

What is the hypophyseal system

A network of blood vessels that carry’s hormones from the hypothalamus to the anterior pituitary

What is the difference between releasing and inhibiting hormones

releasing hormones stimulate hormone release, inhibiting hormones prevent it

Describe the path of releasing hormones in the pituitary

Releasing hormones travel from the hypothalamus through the hypophyseal portal system to the anterior pituitary

Describe the location and hormones of the thyroid and parathyroid glands

Thyroid (neck) T3 T4 calcitonin

Parathyroid’s (posterior thyroid) PTH

Describe the adrenal gland structure and hormones

Cortex- aldosterone, cortisol, androgens

Medulla- epinephrine and norepinephrine

What hormones does the pineal gland secrete and what is it’s function

Melatonin, regulates sleep wake cycles

What does the pancreas secrete and what are the effects

Insulin- lowers blood sugar

Glucagon- raises blood sugar

What does the thymus secrete and what is it’s function

Thymosisns, help secrete the maturation of T cells (immune system)

What hormones does the gonads secrete

Testes- testosterone

Ovaries- estrogen and progesterone

What is the difference between hypo-secretion and hyper-secretion

Hypo- to little hormone

Hyper- to much hormone

Each causes specific disorders

What is diabetes mellitus

A disorder in which insulin is deficient or ineffective, leading to high blood sugar levels

How do endocrine glands develop embryologically

From ectoderm, mesoderm, and endoderm layers depending on the gland

What changes occur in the endocrine system with aging

Decreased hormone levels, reduced sensitivity, and slower metabolic stress response