1 Chapter 13 Endocrine System Endocrine glands are ductless Exocrine glands have ducts.
ENDOCRINE SYSTEM - Warner Pacific Universityclasspages.warnerpacific.edu/BDuPriest/BIO 102... ·...
Transcript of ENDOCRINE SYSTEM - Warner Pacific Universityclasspages.warnerpacific.edu/BDuPriest/BIO 102... ·...
ENDOCRINE SYSTEM
ENDOCRINE SYSTEM
Systemic communication
Involves the release of chemical signals for
transport through the blood to influence cellular
activity
Endocrine glands
Hormones
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Endocrine Glands
Endocrine glands
Glandular tissues that secrete
products (hormones) which
travel through the blood stream
to give instructions to other parts
of the body
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Signal Recognition
Peptide hormones
Bind to receptors at plasma
membrane surface
Do not enter cell
Signal transduction
Message relayed and
amplified through other
intracellular molecules
“2nd messenger system”
Regulates enzyme systems
& gene transcription
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Signal Recognition
Steroid hormones
Pass through plasma
membrane
Bind intracellular receptors
in cytoplasm or nucleus
Regulates gene
transcription
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Hormone Control
Negative feedback
Increased hormone levels inhibit further production
E.g., thyroid hormone
Endocrine gland hormone effector
Positive feedback
Increased hormone levels stimulate further production
E.g., oxytocin
X
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Quick Quiz: A peptide hormone binds
to _________ receptors, then causes a
signal transduction cascade inside the
cell.
A) Intracellular
B) Extracellular
C) Cell surface (plasma membrane)
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Quick Quiz: Negative feedback
_________ the original stimulus.
A) Reinforces
B) Opposes
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Major Vertebrate
Endocrine Glands
Hypothalamus
Pituitary gland
Thyroid gland
Parathyroid glands
Thymus
Adrenal glands
Pancreas
Ovaries / testes
Other (heart, kidneys, liver, stomach,
small intestine, adipose tissue) 9
Hypothalamus & Pituitary Gland
Major hormones of the
posterior pituitary
Produced in hypothalamus,
stored in posterior pituitary
Antidiuretic hormone (ADH)
Targets kidneys
Reabsorb water
Oxytocin (OCT)
Mammary glands milk
letdown
Uterus contractions
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Quick Quiz: Which of these hormones
is NOT released by the posterior
pituitary?
A) Oxytocin
B) Antidiuretic hormone
C) Growth hormone
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Hypothalamus & Pituitary Gland
Hypothalamus controls the
anterior pituitary
Releasing hormones
Inhibiting hormones
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Major Hormones of the Anterior Pituitary
Adrenocorticotropic
hormone (ACTH)
Release of hormones
from adrenal cortex
Thyroid stimulating
hormone (TSH)
Release of thyroid
hormones
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Major Hormones of the Anterior Pituitary
Follicle stimulating
hormone (FSH) &
luteinizing hormone
(LH)
Stimulate hormonal
secretions of gonads
Prolactin (PRL)
Stimulates milk
production
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Major Hormones of the Anterior Pituitary
Growth hormone
(GH)
Promotes growth
in all body tissues
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Quick Quiz: Which anterior pituitary
hormone causes the adrenal cortex to
release hormones?
A) TSH
B) FSH
C) GH
D) ACTH
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Growth Hormone Imbalances
Childhood
Overproduction
Gigantism
Underproduction
Dwarfism
Adult
Overproduction
Acromegaly
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Thyroid & Parathyroid
Thyroid gland
Thyroxine / triiodothyronine
Metabolism regulation
Endemic goiter (iodine deficiency)
Calcitonin
Calcium uptake by bone
Parathyroid glands
Parathyroid hormone
Calcium release by bone
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Adrenal Glands
Adrenal cortex
Cortisol
Protein breakdown
(glycolysis)
Aldosterone
Sodium reabsorption
by kidneys
Adrenal medulla
Epinephrine &
norepinephrine
Stimulates
sympathetic response 19
Quick Quiz: Which of the following
hormones is NOT involved in
regulating blood calcium levels?
A) Parathyroid hormone
B) Growth hormone
C) Calcitonin
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Gonads
Testes
Testosterone
Sperm formation
Secondary sex characteristics
Ovaries
Estrogens
Egg maturation; uterine lining development;
secondary sex characteristics
Progesterone
Maintains uterine lining in pregnancy; development
of breast tissue
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Pancreas
Insulin
Targets: liver, muscle
Stimulates glucose uptake
Decrease blood sugar levels
Store as glycogen
Diabetes
Glucagon
Target: liver
Stimulates glycogen breakdown (glucose release)
Raise blood sugar levels
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Pancreatic Hormones
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Thymus
Thymosins
Maturation of T lymphocytes
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Quick Quiz: Which endocrine tissue
produces hormones that regulate
blood sugar?
A) Thyroid
B) Pancreas
C) Thymus
D) Testes
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