Chapter 17 Endocrine System latest
complete update A+ graded
Four mechanisms of communication between cells Gap Junctions
Neurotransmitters
Paracrine
Hormones
Gap Junction pores in cell membrane allow signaling molecules, nutrients, and electrolytes to
move from cell to cell.
Neurotransmitters released from neurons to travel across the synaptic cleft to the second cell.
Paracrine secreted into tissue fluids to stimulate physiology of nearby cells
Hormones chemical messengers that travel in the bloodstream to other tissues and organs
(called targets) that stimulate a physiologic response.`
Unlike the nervous system, the endocrine system o Releases hormones into the bloodstream to
circulate throughout the body
o Responds slowly (seconds or days); hormonal effect may continue for days or longer
How is the nervous system and the endocrine system similar? o Both communicate with
chemicals; several function as both neurotransmitters and hormones.
o Some hormones and neurotransmitters have the same effect on the same organ.
Pituitary glandsuspended from hypothalamus by a stalk - the infundibulum
Pituitary gland is housed in sella turcica of sphenoid bone
Pituitary gland size and shapekidney bean
, Pituitary gland two structures o Anterior pituitary (adenohypophysis)
o Posterior pituitary (neurohypophysis)
Anterior pituitary anatomy linked to the hypothalamus by the hypophysial portal system
How is the Anterior pituitary linked to the hypothalamus by the hypophysial portal system?
o Primary capillaries in the hypothalamus are connected to secondary capillaries in the
anterior pituitary by portal venules.
o Hypothalamic hormones regulate adenohypophysis cells by releasing or inhibiting hormones.
Posterior pituitary anatomy Nerve cell bodies in the hypothalamus pass down the stalk through
the hypothalamo-hypophysial tract and end in the posterior lobe.
o Hypothalamic neurons secrete hormones that are stored in neurohypophysis until released into
blood
The hypothalamic hormones regulate anterior pituitary
Hormones that stimulate the pituitary to release hormones of its own releasing hormones
Hormones that suppress pituitary secretion inhibiting hormones
o Notice they are named by their effect on the anterior pituitary.
hypothalamic hormones produced in hypothalamus and stored/released by posterior pituitary
Oxytocin (OT) and antidiuretic hormone (ADH)
Prolactin Milk synthesis
Thyroid stimulating hormone secrete thyroid hormone
Luteinizing hormone stimulate testes to produce testosterone and ovaries to ovulate, and later to
help maintain pregnancy
Growth hormone widespread tissue growth
Adrenocorticotropic hormonesecretion of glucocorticoids
Follicle stimulating hormone stimulates development of eggs and sperm
Six anterior pituitary hormones Follicle stimulating hormone
Adrenocorticotropic hormone
Growth hormone
Luteinizing hormone
Thyroid stimulating hormone
Prolactin
Two posterior pituitary hormones OT
ADH
complete update A+ graded
Four mechanisms of communication between cells Gap Junctions
Neurotransmitters
Paracrine
Hormones
Gap Junction pores in cell membrane allow signaling molecules, nutrients, and electrolytes to
move from cell to cell.
Neurotransmitters released from neurons to travel across the synaptic cleft to the second cell.
Paracrine secreted into tissue fluids to stimulate physiology of nearby cells
Hormones chemical messengers that travel in the bloodstream to other tissues and organs
(called targets) that stimulate a physiologic response.`
Unlike the nervous system, the endocrine system o Releases hormones into the bloodstream to
circulate throughout the body
o Responds slowly (seconds or days); hormonal effect may continue for days or longer
How is the nervous system and the endocrine system similar? o Both communicate with
chemicals; several function as both neurotransmitters and hormones.
o Some hormones and neurotransmitters have the same effect on the same organ.
Pituitary glandsuspended from hypothalamus by a stalk - the infundibulum
Pituitary gland is housed in sella turcica of sphenoid bone
Pituitary gland size and shapekidney bean
, Pituitary gland two structures o Anterior pituitary (adenohypophysis)
o Posterior pituitary (neurohypophysis)
Anterior pituitary anatomy linked to the hypothalamus by the hypophysial portal system
How is the Anterior pituitary linked to the hypothalamus by the hypophysial portal system?
o Primary capillaries in the hypothalamus are connected to secondary capillaries in the
anterior pituitary by portal venules.
o Hypothalamic hormones regulate adenohypophysis cells by releasing or inhibiting hormones.
Posterior pituitary anatomy Nerve cell bodies in the hypothalamus pass down the stalk through
the hypothalamo-hypophysial tract and end in the posterior lobe.
o Hypothalamic neurons secrete hormones that are stored in neurohypophysis until released into
blood
The hypothalamic hormones regulate anterior pituitary
Hormones that stimulate the pituitary to release hormones of its own releasing hormones
Hormones that suppress pituitary secretion inhibiting hormones
o Notice they are named by their effect on the anterior pituitary.
hypothalamic hormones produced in hypothalamus and stored/released by posterior pituitary
Oxytocin (OT) and antidiuretic hormone (ADH)
Prolactin Milk synthesis
Thyroid stimulating hormone secrete thyroid hormone
Luteinizing hormone stimulate testes to produce testosterone and ovaries to ovulate, and later to
help maintain pregnancy
Growth hormone widespread tissue growth
Adrenocorticotropic hormonesecretion of glucocorticoids
Follicle stimulating hormone stimulates development of eggs and sperm
Six anterior pituitary hormones Follicle stimulating hormone
Adrenocorticotropic hormone
Growth hormone
Luteinizing hormone
Thyroid stimulating hormone
Prolactin
Two posterior pituitary hormones OT
ADH
