Endocrine System Flashcards
What do the endocrine and nervous systems cooperate together to do?
regulate different functions of other organ systems
Describe the speed of nervous system activation.
usually brief and fast
Describe the speed of endocrine system activation.
much broader and targets virtually all organ systems
What are hormones?
secretions of endocrine glands directly released into bloodstream, and circulate throughout body
What does the endocrine system consist of? (5)
major glands including pituitary, thyroid, parathyroid, pineal, and adrenal glands that produce a wide variety of hormones
What are the organs that are not considered as glands, but contain cells that produce hormones? (11)
heart, liver, pancreas, stomach, intestine, thymus, ovaries, testes, skin, hypothalamus, and placenta
Pituitary Gland (Hypophysis)
What is the pituitary gland?
oval-shaped structure located in hypophyseal fossa of sphenoid bone in middle cranial fossa
Pituitary Gland (Hypophysis)
What does it attach to?
attaches to hypothalamus by (infundibulum) connecting stalk
Pituitary Gland (Hypophysis)
What does it do?
regulates secretions of most of the other glands
Pituitary Gland (Hypophysis)
What is it controlled by?
hormones of hypothalamus
Pituitary Gland (Hypophysis)
What does it consist of?
2 separates lobes:
- anterior pituitary (adenohypophysis)
- posterior pituitary (neurohypophysis)
Pituitary Gland (Hypophysis)
What is it supplied by?
arterial circle of Willis
Pituitary Gland (Hypophysis)
What is its function regulated by?
primarily regulated by hormonal feedbacks through hypothalamus
Pineal Gland (Epiphysis Cerebri)
What is the pineal gland?
small, red, cone-shaped structure that attaches to posterior wall of third cerebral ventricle
Pineal Gland (Epiphysis Cerebri)
What does it do?
its secretions control circadian rhythm, and distribution of melanin pigments in skin
Pineal Gland (Epiphysis Cerebri)
What happens to this gland in elderly people?
calcified
Pineal Gland (Epiphysis Cerebri)
What is it supplied by?
posterior cerebral artery
Pineal Gland (Epiphysis Cerebri)
What is its function controlled by?
hormonal feedbacks
Thyroid Gland
What is the thyroid gland?
butterfly-shaped thyroid gland is situated in neck, anterior to trachea, and inferior to larynx
Thyroid Gland
What does it consist of?
2 lateral lobes connected together by isthmus
Thyroid Gland
What is the isthmus?
slender connection anterior to trachea at level of 2nd or 3rd cartilage rings of trachea
Thyroid Gland
What is the pyramidal lobe?
small third lobe immediately superior to isthmus, in 50% of individuals
Thyroid Gland
What do the 2 lateral lobes relate to?
- thyroid and cricoid cartilages medially
- common carotid arteries laterally
lobes extend superiorly to inferior border of thyroid cartilage of larynx
Thyroid Gland
What do thyroid hormones do?
regulate either metabolic rate of body, or blood calcium level
Parathyroid Gland
What are the parathyroid glands?
4 pea-sized reddish brown mass of glandular tissue partially embedded within posterior surface of lateral lobes of thyroid gland
Parathyroid Gland
What does parathyroid hormone do?
cooperates with thyroid hormone (calcitonin) in blood calcium level regulation
What supplies the thyroid and parathyroid glands?
- superior and inferior thyroid arteries
- branches of external carotid
- subclavian arteries
What regulates activities of the thyroid and parathyroid glands?
hormonal feedbacks, or level of blood calcium
Suprarenal Glands (Adrenal Glands)
Where are these glands?
located on superior pole of kidneys, while surrounded by separate capsule
Suprarenal Glands (Adrenal Glands)
What is the shape of the right gland?
pyramidal-shaped
Suprarenal Glands (Adrenal Glands)
What is the shape of the left gland?
crescent-shaped
Suprarenal Glands (Adrenal Glands)
What can you see in the coronal/frontal section? (2)
- superficial cortex
- deep medullary part
Suprarenal Glands (Adrenal Glands)
What do hormones of the superficial cortex do?
contribute in balancing level of sodium and glucose, or regulation of sexual activities
Suprarenal Glands (Adrenal Glands)
What is the function of the superficial cortex regulated by?
hormonal feedbacks
Suprarenal Glands (Adrenal Glands)
What do hormones of the deep medullary part do?
mimic function of sympathetic nervous system
Suprarenal Glands (Adrenal Glands)
What is the function of the deep medullary part regulated by?
preganglionic sympathetic fibers carried by greater, lesser, and least splanchnic nerves
Suprarenal Glands (Adrenal Glands)
What are chromaffin cells?
modified neurons that act as postganglionic sympathetic neurons
in deep medullary part
Suprarenal Glands (Adrenal Glands)
What is it supplied by?
several branches mainly arising from abdominal aorta and renal arteries
