Endocrine system
includes
Thyroid Gland
Maintain homeostasis
rising blood Ca levels
Thyroid gland releases calcitonin
calcitonin
Stimulates Ca^2+ deposition in bones
Blood Ca^2+ level declines to set point
Reduces Ca^2+ uptake in kidneys
Stimulus
Need for energy
produces
Thyroxine
targets
Most cells in body
effect by
Increasing metabolism
leads to
Shutting down TSH production
triiodothyronine
Calcitonin
effect is
[Ca] taken up by bones
then
excreted by kidneys
targets
Bone
kidneys
Parathyroid gland
Stimulus
[Ca] in blood is too low
Subtopic
produces
Parathyroid hormone
effects
[Ca] released by bones
[Ca] reabsorbed by kidneys
Includes
Posterior Pituitary
which
stores and releases
Stimulus
are
Pressure on opening of uterus
produces
Oxytocin
target tissues
are
Uterus
effect
Contraction
Mammary glands
effect is
Releasing
milk
produced in
hypothalamus
stimulated to
release by
Labour
is
a positive feedback loop
as
head of fetus pushes against cervix
Nerve impulses from cervix transmitted to brain
Brain stimulates pituitary gland to secrete oxytocin
oxytocin carried in bloodstream to uterus
oxytocin stimulates uterine concentration and pushes fetus toward cervix
Nursing
during
breast feeding
Suckling
High [Na] in blood
produces
ADH
target tissue
Kidneys
effect is
increasing
water reabsorption
to prevent
dehydration
Subtopic
includes
Anterior Pituitary
Stimulus
is
releasing and inhibiting hormones
from
hypothalamus
Produces
hormones
such as
TSH
target gland
is
Thyroid gland
effects
Production and release of thyroxine
PRL
target gland
is
Mammary glands
effects
such as
Stimulating breast development
milk production
HGH
target tissues
are
Bones
cartilage
effects are
increasing
calcium absorption
protein synthesis
tissue growth
muscles
ACTH
target gland
is
Adrenal gland
effect is
producing or releasing
cortisol
aldosterone
know as
cortex
FSH
target tissues
are
Testes
in
Males
effect
is
Stimulating sperm production
Follicles
located in
ovaries
in
Females
effects
are
Release estrogen
stimulates egg growth and developmen
secretion of sex hormones
LH
target tissues
are
Testes
effect is
Producing testosterone
Ovaries
effects
are
Produce estrogen
release ovum
follicle
then
produces progesterone
MSH
causes
darkening of skin
in
fish
amphibians
by increasing
production of the dark pigment melanin
called
melanocytes
reptiles
Effect
appetite suppression in humans
there isn't
clear details yet
Endorphins
Influence
pain receptors
in
brain
Includes
Glands in Skin/Kidneys
which Stimulus
Sun - UV radiation of cholesterol
found in
cell membranes
makes
Vitamin D
target tissues
are
Small intestine
kidneys
bones
Effect
increasing
Ca absorption in the SI
increase of Ca re-absorption in kidneys
releasing
Ca from bones into blood
leading to
increase [Ca] in the blood
Consists of
several organs
called
glands
Located
Throughout the body
Create & secrete
hormones
Are
chemicals
coordinates
different functions in the body
by
carrying messages through the blood
Notify
the body what to do and when to do it
to the
organs
skin
muscles
Released into the blood
affect
cells in another part of the body.
controlled by
Feedback loops
usually
negative
Antagonistic hormones
is
opposing actions
have
two types
Steroid hormones
are
Lipid soluble
Hydrophobic
is not
soluble in blood
thus
combine with a hydrophilic protein carrier
to move
through the blood
can
pass through lipid bilayer
made from
cholesterol
Bind to
receptors inside target cell
Example
sex hormones
cortisol
Protein hormones
are
Not lipid soluble
Hydrophilic
meaning
water soluble
thus
cannot enter plasma membrane of target cells
Bind to
receptors on cell surface
Consist of
amino acids chains
length ranges
3 a.a to more than 200 a.a
Example
Growth factors
Monitors
Functions
are
maintaining homeostasis
by
an interaction between
both
endocrine system
nervous system
Regulation of growth and development
Control the process of sexual reproduction
such as
gametogenesis
fertilization
fetal growth and development
nourishment of the newborn
if it isn't healthy
leads to
problems
such as
developing during puberty
getting pregnant
managing stress
gaining weight easily
weak bones
lack energy
due to
too much sugar staying in the blood
instead of
moving into your cells
where
needed for energy
disorders
such as
Cushing’s syndrome
known as
hypercortisolism
is
a hormonal disorder
caused by
prolonged exposure of the body’s tissue to high levels of cortisol.
Symptoms
such as
High blood pressure
High blood glucose
Muscle weakness
Fluid retention
Addison disease
known as
hypoadrenocorticism
is
adrenocortical insufficiency
due to
dysfunction of the entire adrenal cortex
Symptoms
such as
Low blood pressure
Weight loss
Muscle weakness
Loss of appetite
Hyperthyroidism
increases
thyroxine
Autoimmune disorder
attacks
TSH receptors on thyroid cells
making them
permanently on
leading
thyroid cells to continuously divide
produce thyroxine
Symptoms
including
muscle weakness
increase in
BMR
weight loss
appetite
heat
sweating
bulging eyes
Treatment
such as
remove thyroid
thyroid blocking drugs
radioactive iodine
to
destroy affected tissue
Hypothyroidism
Decrease
thyroxine
caused by
iodine deficiency
produces
TSH
but
unable to make thyroxine
thus
thyroid is stimulated
to
divide/grow
can cause
goiter
Symptoms
for example
Increase weight gain
Decrease in
BMR
HR and output
Subtopic
appetite
heat
Treatment
is using
thyroxine supplements
Vitamin D deficiency
takes place
Infant
causing
Rickets
leads to
Skeletal deformities
increase Fractures
Impairs normal growth
Adult
causing
Osteomalacia
leading to
Soft bones
HGH
Decrease HGH
happens
When young
leads
pituitary dwarfism
being
small
but
normal proportion
causes
late or no puberty
When old
leads
HGH naturally decrease
causing
decrease protein synthesis
maybe the reason
decreasing muscle mass
Increase HGH
takes place
Young
causing
Gigantism
results in
increasing
growth of long bones
Adult
causing
Acromegaly
results in
increasing
thickness of bones
in
face
hands
feet
Diabetes
has
3 types
Type 1 diabetes
is
Insulin dependent
Early degeneration of beta cells
Diagnosed in
childhood
Unable to
produce insulin
Type 2 diabetes
is
Non-Insulin dependent
Diagnosed in
adulthood
Decreased
insulin production
or
ineffective use of insulin
Controlled with
diet
exercise
sulfonamide drugs
stimulate
islets of langerhans
Gestational diabetes
is
Temporary condition
occurs in
2-4% of pregnancies
Treatment
is using
Insulin injections
useful for
regulating blood sugar
Monitor blood sugar
doesn't prevent
serious complications
such as
stroke
blindness
should be balanced
with
meals
exercise
feedback loop
to
maintain homeostasis
for example
blood glucose levels
if high
Stimulus is
Rising blood glucose level
Beta cells of pancreas stimulated to release insulin into the blood
Insulin
Liver takes up glucose and stores it as glycogen
Body cells take up more glucose
Blood glucose level declines to a set point; stimulus for insulin release diminishes
if low
Stimulus is
Low blood glucose level
Alpha cells of pancreas stimulated to release glucagon into the blood
Glucagon
Liver breaks down glycogen and releases glucose to the blood
Blood glucose level rises to set point; stimulus for glucagon release diminishes
Removal of excess glucose from blood
includes the
Hypothalamus gland
Regulates
Pituitary gland activities
by
neurosecretory cells
Produces
neurohormones
Made by
neurons
Releasing hormones
effect is
Release of anterior pituitary hormones
Release inhibiting hormones
effect is
Stops the release
of
anterior pituitary hormones
Stimulus
both
Nervous system
endocrine system
target gland
is
Pituitary gland
includes
Pancreas
Stimulus
are
Low glucose levels
Effects
are
Breakdown of glycogen
release of glucose
Produces
Glucagon
High glucose levels
Produces
Insulin
Target Tissue
Liver and muscle cells
Effect
is
Uptake of glucose
to be
stored as glycogen
Includes the
Pineal Gland
Stimulus
both
Circadian rhythm
darkness
Produces
Melatonin
Target Tissue
is
Brain
Effect
is
Making you sleepy
only if
in the dark
lack of it
leads
making you awake (in light)
Includes the
Thymus gland
Stimulus
the
Body feedback
when
T cells are needed
Produces
Thymosin
Target Tissue
is
Immune system
Effect
is
Maturing T cells
Includes
Adrenal Glands
Adrenal cortex
Stimulus
ACTH
Produces
Cortisol
Target Tissues
are
Muscles
Adipose tissue
Capillaries
Immune system
Effect
include
Break down of muscle and fat
to increase
available energy
decreasing
permeability of capillaries
in
affected tissues
Aldosterone
Target Tissues
are
Kidneys
Colon
Effect
is
Increasing Na absorptio
in both
colon
kidneys
causing
higher blood pressure
Adrenal medulla
Stimulus
ACTH
Produces
Adrenaline
Noradrenaline
Target Tissue
includes
Heart
Blood vessels
lungs
nervous system
Effects
is
increasing
HR
breathing rate
blood flow
to
muscles
heart
dilation of pupils
glycogen break down
Includes
Ovaries
Contributes to
female development
Contain
Group of cells
Called
Follicles
are
Primary oocyte
Granulosa cells
at puberty
400000
develop
during each cycle
but
only one reaches maturity
Stimulus
LH
Produces
Progesterone hormone
Target Tissue
is
Ovaries
Effects
are
Preventing development of other follicles
Inhibits LH production
Puberty,
FSH
Produces
Estrogen
Target Tissues
are
Uterus, hypothalamus
Many cells
Effects
are
Thickening of uterus
Increases LH production,
Inhibits FSH production
Secondary sex characteristics
such as
breast development
increase in body fat
growth of body hair
widening of the hips
Includes
Testes
Contributes to
Male development
Stimulus
FSH
produces
Inhibin
Target Tissue
is
Hypothalamus
Effect
is
Inhibits production of FSH
Puberty, LH
Producess
Sperm cells
Testosterone
Target Tissue
Many cells
Effects
Secondary sex characteristics
Such as
increase in muscle
Lowering of voice
growth of body hair
decrease in fat
Inhibits LH production
body temperature
when high
Sensor: thermoreceptors signal an increase in temperature
Integrator
Hypothalamus turns on cooling systems
Effector: sweat glands initiate sweating; evaporation of swear causes cooling
Effector: Skin blood vessels dilate; increased blood flow to skin; thermal energy loss from skin
Result
Body temperature decreases; hypothalamus turns off cooling systems