JOFRED M. MARTINEZ, MAN, RN
God the Father
Creator of all things
living and no-living
true source of light and wisdom
enlighten our heart and mind
to follow your will today
help us to avoid confusions
and lead us to clarification
let your sublime wisdom
penetrate our humanity…
and your light
shine our dark parts
give us the source of inspiration
that we may become also
an inspiration to others.
we ask this through Christ our Lord
AMEN.
Thyroid
gland
Endocrine
gland
Hormone secretion
Endocrine
cell
Blood flow
(a)
Skin
Duct
Exocrine gland
(sweat gland)
Exocrine
cells
(b)
The cells, tissues, and organs are called
endocrine glands
• They are ductless
• They use the bloodstream
• They secrete hormones
• There are also similar glands called
paracrine and autocrine glands that
are quasi-endocrine
Glands that secrete substances are the
exocrine glands
• They have ducts
• They deliver their products directly to
a specific site
Nerve impulse
Neuron
transmits
nerve
impulse
Glandular
cells secrete
hormone into
bloodstream
Neurotransmitter
released into
synapse
Bloodstream
Postsynaptic
cell responds
Target cells
(cells with hormone
receptors) respond
to hormone
Hormones have no
effect on other cells
Hypothalamus
Pituitary gland
Parathyroid gland
Pineal gland
Thyroid gland
Thymus
Adrenal gland
Kidney
Pancreas
Ovary
(in female)
Testis
(in male)
Chemically, hormones are either:
• Lipid-soluble Hormones
 Steroid hormones
 Thyroid hormones
 Nitric oxide (NO)
• Water-soluble Hormones
 Amine hormones
 Peptide hormones and protein
hormones
 Eicosanoid hormones
1. Hormonal mechanism: for example, the hypothalamus secretes
hormones that stimulate the anterior pituitary gland to secrete
hormones that stimulate other endocrine glands to secrete
hormones.
2. Humoral mechanism: for example, capillary blood contains a low
concentration of calcium that stimulates secretion of parathyroid
hormone. Parathyroid hormone makes serum calcium go up.
3. Neural mechanism: preganglionic SNS fiber stimulates the
adrenal medulla cells to secrete catecholamines.
–
Hypothalamus
–
Nervous system
–
Changing level
of substance
in plasma
– Anterior pituitary gland
Peripheral
endocrine
gland
Endocrine
gland
Endocrine
gland
Target cells
Target cells
Target cells
Action
Action
Action
ORTICOTROPIN-RELEASING HORMONE
ROWTH HORMONE-RELEASING HORMONE
ONADOTROPIN-RELEASING HORMONE
ROWTH HORMONE- INHIBITORY HORMONE
HYROTROPIN-RELEASING HORMONE
ROLACTIN - INHIBITING HORMONE
ELANOCYTE - STIMULATING HORMONE
Third ventricle
Hypothalamus
Anterior cerebral
artery
Optic chiasma
Optic nerve
Oculomotor
nerve
Pituitary stalk
(Infundibulum)
Trochlear nerve
Anterior lobe
of pituitary gland
Posterior lobe
of pituitary
gland
Sella turcica
Sphenoidal
sinus
Sphenoid bone
Basilar artery
ROWTH / SOMATOTROPIC HORMONE
HYROID-STIMULATING HORMONE
ROLACTIN / LACTOGENIC HORMONE
DRENOCORTICOTROPIC HORMONE
UTEINIZING HORMONE
OLLICLE-STIMULATING HORMONE
ELANOCYTE-STIMULATING HORMONE
• Growth hormone (GH): controls growth and protein,
carbohydrate, and lipid metabolism. Production of growth
hormone is controlled by two other hormones:
1. Somatostatin: inhibits growth hormone.
2. Somatotropin: stimulates secretion of growth hormone.
• The majority of growth hormone is secreted during sleep. Other
factors that increase secretion of growth hormone are exercise,
stress, hypoglycemia, starvation, and hypothyroidism.
1. Prolactin: stimulates breast growth and production of milk.
2. FSH: stimulates development of egg and sperm and secretion
of sex hormones.
3. LH: stimulates the production of progesterone and regulates
ovulation in women, and regulates testicular growth,
testosterone production, and androgen production in men.
To stimulate the release of these gonadotropic
hormones, gonadotropin-releasing hormone (GnRH)
must be present.
Important for cervical dilatation prior to birth, and helps the uterus to
contract during labor and delivery, especially during the second and
third stages. In breast-feeding (lactating) mothers, oxytocin causes
milk to be “let down” into area of breast where baby can suckle and
receive milk.
When ADH is secreted, WATER is retained in the vascular space.
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
Larynx
Colloid
Thyroid
gland
Follicular
cell
Follicular cells
Colloid
Isthmus
Extrafollicular
cell
(a)
(b)
Extrafollicular
cells
© Fred Hossler/Visuals Unlimited
When thinking about thyroid hormones think energy
and metabolism!
1. Increases the metabolism of protein, fat, and glucose.
2. Increases body temperature in response to an elevated
metabolism, which produces body heat.
3. Increases the use of oxygen as metabolism increases.
4. Aids in the development of the neural and skeletal systems in
fetuses.
5. Helps regulate secretion of growth hormone.
6. Aids in production of red blood cells.
7. Affects respiratory rate: too much thyroid hormone increases
respiratory rate, and too little decreases respiratory rate.
8. Aids in normal growth and development.
• Both T3 and T4 increase metabolic rate of cells and tissues.
• T4 is the precursor to T3.
• T3 regulates the metabolic rate of all cells and all processes of cell
growth and tissue differentiation.
• T3 and T4 indirectly increase blood glucose levels.
• Being cold increases the conversion of T4 to T3.
• Things such as stress, starvation, certain dyes, and certain drugs
like steroids, beta-blockers, PTU (propylthiouracil), and
amiodarone decrease the conversion of T4 to T3.
• Targets the bones, kidneys, and epithelial cells of the intestines.
• Decreases blood/serum calcium in three ways:
1. Decreases intestines’ ability to absorb calcium.
2. Decreases osteoclast activity in the bones.
3. Decreases calcium resorption from the kidney tubules.
Bone resorption occurs when osteoclasts break down
bone and release calcium from the bone into the
blood.
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
Pharynx
Secretory cells
Thyroid
gland
Capillaries
Parathyroid
glands
© R. Calentine/Visuals Unlimited
Esophagus
Trachea
Posterior view
Foods
Cholesterol
Intestinal enzymes
Provitamin D
Ultraviolet light in skin
Vitamin D
(Cholecalciferol)
Also obtained directly
from foods
Liver
Hydroxycholecalciferol
Kidney
Stimulated by PTH
Dihydroxycholecalciferol
(active form of vitamin D)
Controls absorption of
calcium in intestine
Ca+2
Ca+2
Ca+2
• Parathyroid hormone (PTH) makes
the serum calcium level go up!
• Too much PTH
hyperparathyroidism
hypercalcemia,
hypophosphatemia, bone damage,
and renal damage.
• Too little PTH hypoparathyroidism,
hypocalcemia,
hyperphosphatemia, hyperreflexia,
and cognitive changes (altered
sensorium).
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
Parathyroid glands (on
posterior of thyroid gland)
Release into
bloodstream
Decreased blood calcium
stimulates parathyroid
hormone secretion
Stimulation
–
Increased blood
calcium inhibits
PTH secretion
Inhibition
PTH
Bloodstream
PTH
Ca+2
+
Bone
releases Ca+2
PTH
+
Ca+2
Kidneys
conserve Ca+2 and
activate Vitamin D
Active
Vitamin D
Ca+2
Intestine
absorbs Ca+2
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
Surface of
adrenal gland
Capsule
Zona
glomerulosa
Connective
tissue capsule
Adrenal gland
Zona
lomerulosa
Kidney
Cortex
Zona
fasciculata
Adrenal
cortex
Adrenal cortex
Adrenal
medulla
Medulla
Zona
reticularis
Zona
reticularis
(a)
(b)
Chromaffin
cells
© Ed Reschke
Zona
fasciculata
Adrenal
medulla
Many heart attacks occur during the early morning hours when
people are coming out of REM sleep, as this is a very stressful
time for the body.
1. Stimulate gluconeogenesis (the formation of carbohydrates from
proteins and other substances by the liver).
2. Provide amino acids and glucose during times of stress.
3. Suppress the immune system due to powerful immunosuppressive
and anti-inflammatory properties.
4. Stimulate fat breakdown.
An increase in aldosterone secretion is also caused by:
• Low fluid volume levels in the vascular space as in shock or
hypovolemia.
• High blood levels of potassium.
The illnesses associated with aldosterone are:
• Hyperaldosteronism (Conn’s syndrome)
• Hypoaldosteronism
Sex hormones are usually broken down into three categories:
1. Androgens, testosterone being the main one.
2. Estrogens, estradiol being the main one.
3. Progestagens, progesterone being the main one.
Synthetic androgens (sex hormones) are referred to
as anabolic steroids.
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
Pancreatic islet (Islet of Langerhans)
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
Gallbladder
Common bile duct
Pancreatic duct
Duct
Small
intestine
Digestive enzymesecreting cells
Pancreatic islet
(Islet of Langerhans)
Capillary
Hormone-secreting
islet cells
From Kent M. Van De Graaff and Stuart Ira Fox, Concepts of Human Anatomy and
Physiology, 2nd ed. ©1989 Wm. C. Brown Publishers, Dubuque, Iowa. All Rights
Reserved. Reprinted with permission
Pancreas
Control center
Beta cells secrete
insulin
Receptors
Beta cells detect a rise
in blood glucose
Stimulus
Rise in blood glucose
Effectors
Insulin
• Promotes movement of glucose
into certain cells
• Stimulates formation of glycogen
from glucose
Response
Blood glucose drops toward
normal (and inhibits insulin
secretion)
too high
Normal
blood glucose
concentration
too low
Stimulus
Drop in blood glucose
Receptors
Alpha cells detect a drop
in blood glucose
Response
Blood glucose rises toward
normal (and inhibits glucagon
secretion)
Effectors
Glucagon
• Stimulates cells to break down glycogen
into glucose
• Stimulates cells to convert
noncarbohydrates into glucose
Control center
Alpha cells secrete
glucagon
Pineal Gland
• Secretes melatonin
• Regulates circadian rhythms
Thymus Gland
• Secretes thymosins
• Promotes development of certain lymphocytes
• Important in role of immunity
Reproductive Organs
• Ovaries produce estrogens and progesterone
• Testes produce testosterone
• Placenta produces estrogens, progesterone, and
gonadotropin
Other organs: digestive glands, heart, and kidney
Stress results from changes
in the external environment
Hormonal signals
Neural signals
Signals from
sensory receptors
Sympathetic impulses
Hypothalamus
Adrenal medulla
Epinephrine and
norepinephrine
released
CRH released
Anterior pituitary
Norepinephrine
released
Short-term “fight or flight” or alarm stage.
• Blood glucose increases.
• Blood glycerol and fatty acids increase.
• Heart rate increases.
• Blood pressure rises.
• Breathing rate increases.
• Air passages dilate.
• Pupils dilate.
• Blood flow redistributes.
ACTH released
Adrenal cortex
Cortisol released
Long-term adjustment or resistance stage
• Increase in blood concentration of amino acids.
• Increased release of fatty acids.
• Increased glucose formed from
noncarbohydrates—amino acids (from
proteins) and glycerol (from fats).
• Endocrine glands decrease in size
• Muscular strength decreases as GH levels decrease
• ADH levels increase due to slower break down in liver and
kidneys
• Calcitonin levels decrease; increase risk of osteoporosis
• PTH level changes contribute to risk of osteoporosis
• Insulin resistance may develop
• Changes in melatonin secretion affect the body clock
• Thymosin production declines increasing risk of infections
test
Normal values
significance
Thyroid-stimulating
hormone
0.5–5.0 U/mL
↑ in primary hypothyroidism
↓in primary hyperthyroidism
Triiodothyronine (T3)
80–200 ng/100 mL ↓ in hypothyroidism
↑ in hyperthyroidism
Thyroxine (T4 )
4–12 g/100 mL
↓ in hypothyroidism
↑ in hyperthyroidism
test
Normal values
significance
Parathyroid
hormone
25 pg/mL
↑ in primary hyperparathyroidism
↓ in primary hypoparathyroidism,
parathyroid trauma during thyroid
surgery
Calcium
8.5–10.5 mg/100 mL
↑ in some cancers,
hyperparathyroidism
↓ in hypothyroidism
Phosphorus
2.4–4.7 mg/dL
↑ in hypoparathyroidism
↓ in hyperparathyroidism
test
Normal values
significance
Growth hormone
5 ng/mL
↑ in acromegaly
↓ in small stature
Antidiuretic
hormone
2.3–3.1 pg/mL
↑ in SIADH
↓ in diabetes insipidus
Urine specific
gravity
1.010–1.025
↓ in diabetes insipidus
Adrenocorticotropic 120 pg/mL at 6–8 a.m.
hormone
↑ in Addison’s disease
↓ in Cushing’s syndrome, longterm corticosteroid therapy
test
Normal values
significance
Cortisol
5–25 g/100 mL
↑ in Cushing’s syndrome, stress
↓ in Addison’s disease, steroid
withdrawal
Vanillylmandelic
acid (VMA)
0.7–6.8 mg/24 h
↑ in pheochromocytoma
test
Normal values
significance
Fasting plasma
glucose (FPG)
70–100 mg/dL
in stress, Cushing’s syndrome
FPG 101–125 pre-diabetes
FPG 126 diabetes mellitus
↓ in hypoglycemia, Addison’s
disease
Oral glucose
tolerance test
Blood glucose less
than 140 mg/dL at 2
hours
BG 140–199 at 2 hours prediabetes; BG 200 at 2 hours
diabetes mellitus
Glycosylated
hemoglobin
4%–7%
↑ in poor diabetes control
• A thyroid scan may be done to determine the presence of
tumors or nodules.
• A computed tomographic (CT) scan or magnetic resonance
imaging (MRI) may be done to locate a tumor or identify
hypertrophy of a gland.
• Ultrasound may be done of the thyroid or parathyroid glands to
determine if they are enlarged or to find masses.
• Biopsy is done to obtain tissue to examine for possible
cancerous cells.