Endocrine system Flashcards
Anterior Pituitary
1 .Growth hormone - Stimulate bone and muscle
- Thyroid stimulating hormone
- Adrencorto tropic - Stimulate the adrenal cortex
- Follicle stimulating hormone - production of egg and sperm
- Lutenizing hormone - release of egg and sperm
- Prolactin - Stimulate milk production
Posterior pituitary
Oxytocin- releases milk from breast + bonding hormone
Antidiuretic- prevent water overload and dehydration
Thyroid
Thyroid Hormone
Calcitonin
BOTH ENERGY PRODUCTION
Parathyroid
Parathyroid Hormone -
Increases Ca2+
Adrenal cortex - LONG TERM STRESS RESPONSE
mineralcorticoids - INCREASE mineral content
Glucocorticoids- INCREASE glucose levels in the blood - this is the long term stress response -
Gonadcorticoids- sexual response
Adrenal Medulla - SHORT TERM STRESS RESPONSE
- Epinephrine
- NOR Epinephine
Pancreas
Glucagon -Incraese blood glucose
Insulin - decrease blood glucose
Ovaries
- estrogen
- progestrone
FEMALE REPRODUCTIVE HORMONES
Testies
Testosterone
Pineal gland
Melatonin -
body rythem
AUTOcrines
AUTOcrines - chemicals that exert their effects on the same cells that produce them
Paracrines-
Locally acting chemicles that affect cells other than those that secrete them
Hormones
Long distance acting chemicals
Regulate the metabloloc function of other cells
have lag times ranging from seconds to hours
Tend to have prolonged affects
Are classified as aminoacid based hormones or steriods
Eicosanoids
biologically active lipids with local hormones like activity
Target Cell Specificity
Hormones circulate to all tissues but only activate
cells referred to as target cells
▪ Target cells must have specific receptors to which
the hormone binds
▪ These receptors may be intracellular or located on
the plasma membrane
Concentration of the circulating hormone reflect
rate of release
speed of inactivation and removal from the body
Hormones are removed from the blood by
Dgrasding enzymes
Kidneys
Liver Enzyme systems
Humoral stimuli
secretion of hormones in direct
response to changing blood levels of ions and
nutrients
Neural Stimuli
Neural stimuli – nerve
fibers stimulate hormone
release
▪ Preganglionic
sympathetic nervous
system (SNS) fibers
stimulate the adrenal
medulla to secrete
catecholamines
Hormonal Stimuli
release of hormones in response
to hormones produced by other endocrine organs
The hypothalamic hormones stimulate the anterior
pituitary
▪ In turn, pituitary hormones stimulate targets to
secrete still more hormones
Nervous System Modulation
The nervous system can override normal endocrine
controls
▪ For example, control of blood glucose levels
▪ Normally the endocrine system maintains blood
glucose
▪ Under stress, the body needs more glucose
▪ The hypothalamus and the sympathetic nervous
system are activated to supply ample glucose
Pituitary-Hypothalamic Relationships:
Posterior Lobe
Has a neural connection with the hypothalamus
(hypothalamic-hypophyseal tract)
▪ Nuclei of the hypothalamus synthesize oxytocin and
antidiuretic hormone (ADH)
▪ These hormones are transported to the posterior
pituitary
The six hormones of the adenohypophysis: anterior lobe
Are abbreviated as GH, TSH, ACTH, FSH, LH,
and PRL
▪ Regulate the activity of other endocrine glands
Effects of Thyroid Hormone
TH is concerned with:
▪ Glucose oxidation
▪ Increasing metabolic rate
▪ Heat production
▪ TH plays a role in:
▪ Maintaining blood pressure
▪ Regulating tissue growth
▪ Developing skeletal and nervous systems
▪ Maturation and reproductive capabilities
Calcitonin targets the skeleton
▪ Inhibits osteoclast activity (and thus bone
resorption) and release of calcium from the bone
matrix
▪ Stimulates calcium uptake and incorporation into
the bone matrix
▪ Regulated by a humoral (calcium ion concentration
in the blood) negative feedback mechanism
Mineralocorticoids
Aldosterone secretion is stimulated by:
▪ Rising blood levels of K+
▪ Low blood Na+
▪ Decreasing blood volume or pressure
Rods
▪ Rods respond to low-intensity light and provide night and peripheral vision.
Cones
Cones are bright-light, high-discrimination receptors that provide colour
vision.
Anything that must be viewed precisely is focused on the
cone-rich fovea
centralis.
