(14) The Endocrine System Flashcards
primary endocrine organs
– exclusive function:
secrete hormone
primary endocrine organs includes:
– pituitary gland (hypophysis cerebri)
– pineal gland (epiphysis cerebri)
– thyroid glands
– parathyroid glands
– adrenal glands
– have endocrine function in addition to serving in other capacities
major endocrine organs
major endocrine organs Includes:
– Ovaries
– Testes
– Pancreas
– Have endocrine function that is secondary or has other major functions
minor endocrine glands
minor endocrine glands Includes:
– Kidneys
– Liver
– Thymus
– Fetal membranes/placenta
– A reddish appendage attached at the ventral midline to the diencephalon
– Called the “Master Gland”; although small, it plays a major regulatory role in the entire endocrine system
Hypophysis or the Pituitary Gland
– Unpaired, cream-colored, wedge-shaped small excrescence on the dorsal midline surface of the diencephalon and where it is part of the epithalamus.
– Growth upon the cerebrum
– Not visible from external surface
– Produces melatonin
– Functions as a biological clock regulating both diurnal and seasonal variation in gonadal activity
Pineal Gland (formerly epiphysis)
Pineal Gland (formerly epiphysis) Produces?
melatonin
– Largest endocrine gland; Two separate lobes, elongated symmetrical ovals, generally dark red in color
– Lies on the ventrolateral surface of the trachea immediately caudal to the larynx
Thyroid Gland
Two types of endocrine cells:
– Follicular cells
– Parafollicular cells (C cells)
– Represent majority of the secretory cells in the gland
– Secretes thyroid hormone, stored within the gland and released as needed
– Controls many of the body’s metabolic process
Follicular cells
Follicular cells secretes what hormone?
thyroid hormone
– These cells are fewer in number
– Secretes calcitonin
– Stimulates skeleton to take up calcium thus lowering level of calcium in the blood
Parafollicular cells (C cells)
Parafollicular cells (C cells) secretes?
calcitonin
– Smallest endocrine glands
– Produces parathormone essential for normal metabolism of calcium
– Promotes calcium absorption from the gut
– Mobilizes calcium from skeleton
– Induce excretion of calcium in the urine
Parathyroid Glands
Adrenal Glands
– Paired organs that are flat elongated and roughly rectangular
– Lies sandwiched between two companion vessels, the common trunk of the caudal phrenic and cranial abdominal arteries and veins (veins – ventral to gland, arteries – dorsal to gland)
What adrenal glands located between kidney and aorta
Left adrenal gland
What adrenal gland located between kidney and caudal vena cava
Right adrenal gland
Adrenal cortex is a major steroid-producing organ – produce ? that regulate mineral balance via normal kidney function and most useful for carbohydrate metabolism
steroid hormone (mineralocorticoids & glucocorticoids)
Medulla produces ? augments together with nervous system , the general adaptation of the body to stress
epinephrine and norepinephrine
These two combine to influence markedly the organism’s response to both acute and chronic stress
cortex and medulla
Pancreatic islets (Islet of Langerhans) secrete ? to regulate blood sugar levels
insulin and glucagon
Ovaries
– Corpus luteum – source of?
progesterone
– Corpus luteum – source of progesterone
– In pregnant bitch, provides levels of progesterone sufficient to maintain pregnancy
Ovaries
– During last two trimester of pregnancy produce progesterone sufficient to maintain pregnancy and bring it to term
Placenta
These cells are the source of male androgens including testosterone
Interstitial cells (of Leydig)
Interstitial cells (of Leydig) – source of male androgens including
testosterone
Testes
– Juxtaglomerular cells has secretory granules which contains renin which plays a role in increasing the blood pressure
Kidney
What cells has secretory granules which contains renin which plays a role in increasing the blood pressure
Juxtaglomerular cells
