Endocrine System Flashcards
secretion of hormone function
-chemical messengers/regulators which affect the activity of other cells
what results from endocrine glands being ductless?
-they secrete their products directly into the bloodstream
are endocrine glands vascular or avascular?
- vascular
- has very rich blood supply
characteristics of the effects on target tissues
- slow but long-lasting
- opposite of CNS & PNS
how is hormone secretion controlled?
- negative feedback mechanism
- neural control
what part of the brain controls the release of hormones?
- hypothalamus
- secretes substances called releasing factors
pituitary gland location
- inferior surface of brain
- attached to hypothalamus
- surrounded by circle of willis
pituitary gland structure components
- adenohypophysis
- neurohypophysis
pituitary gland adenohypophysis location
- anterior lobe
- glandular portion
pituitary gland adenohypophysis function
- produces and secretes six major hormones
- portal supply to anterior gland receives releasing factors
pituitary gland neurohypophysis location
- posterior lobe
- nervous portion
pituitary gland neurohypophysis nervous portion function
- stores and releases 2 hormones produced by hypothalamus
- dilated terminal axons that store hormone until neurons fire, releasing hormone into circulation
pituitary gland function
- “master gland” of the body
- regulates many of body’s activities by releasing specific hormones to impact other endocrine glands
pituitary gland is divided into what?
- anterior pituitary
- posterior pituitary
anterior pituitary gland hormones it secretes
- growth hormone
- thyroid stimulating hormone
- adrenocorticotropic hormone
- follicle stimulating hormone
- luteinizing hormone
- prolactin
posterior pituitary gland hormones it secretes
- oxytocin
- antidiuretic hormone
anterior pituitary: growth hormone
- GH
- increases protein synthesis and mitosis
- regulates growth of most cell sof the body
anterior pituitary: thyroid-stimulating hormone
- TSH
- regulates the hormonal activity of the thyroid gland
anterior pituitary: adrenocorticotropic hormone**
- ACTH
- controls the secretions of the hormones of the adrenal cortex
anterior pituitary: follicle stimulating hormone
- FSH
- stimulates follicle(ova) development in the ovary and sperm in testes
- stimulates sex hormone secretion
anterior pituitary: luteinizing hormone
- LH
- plays a role in ovulation
- stimulates secretion of sex hormones (estrogen and testosterone)
anterior pituitary: prolactin
-plays a role in secretion and production of milk from mammary glands(lactation)
posterior pituitary: oxytocin
- stimulates uterine and smooth muscle contractions
- promotes milk ejection from breast
posterior pituitary: antidiuretic hormone
- ADH
- affects permeability of kidney tubules to reduce the excretion of water
- secretes vasopressin
what does vasopressin control?
- controls BP
- constricts blood vessels
thyroid gland location
- anterior neck inferior to larynx
- surrounds anterior and lateral aspect of the trachea
thyroid gland gross structure
-two lobes connected by an isthmus
thyroid gland microscopic structure
- cuboidal cells: hormone production
- follicles: stores hormones
thyroid gland hormones it secretes
- thyroxine (T4)
- triiodothyronine (T3)
- calcitonin