Exam 1 Endocrine System (no hormones)

Endocrine System

Maintain homeostasis

Regulate Growth

Control reproduction

Control digestion

Endocrine glands

No ducts

Release hormones

Slower, long-lasting

ex: Pituitary, thyroid, adrenal gland

Paracrine Hormones

Act on neighboring cells

Autocrine Hormones

Act on same cells

Circulating Hormones

Secreted into the bloodstream, traveling long distances to affect distant target cells

Local Hormones

Act on neighboring or self-cells via diffusion, without entering the bloodstream, and are inactivated rapidly

Amine Hormone

Amino acids with modified groups

Peptide Hormone

Short chains of linked amino acids

Protein Hormones

Long chains of linked amino acids

Steroid Hormones

Derived from the lipid cholesterol

Lipid-Soluble Hormones

Hydrophobic, bind to carrier proteins, intracellular, slower, steroids, thyroid hormones

Water-Soluble Hormones

Hydrophilic, free in blood, cell surface, fast, peptides, epinephrine

Synergistic effect

Adaptive/reinforcing, working together

Permissive effect

requires the activity of another hormone

Antagonistic effect

Opposing

Neural Stimulation

Nervous system

ex: sympathetic nervous system fibers stimulate the adrenal medulla to release epinephrine/norepinephrine.

Humoral Stimulation

Blood (solutes)

ex: high glucose levels causes the pancreas to release insulin

Hormonal Stimulation

Another hormone

ex: Hypothalamus releases hormones that stimulate the anterior pituitary gland to release further hormones

Up Regulation

Increased amount of receptors on a cell

Down Regulation

Decreased amount of receptors on a cell

Hypothalamus

Master endocrine gland (along with pituitary)

Directs release of hormones- ADH & OT

Indirect control- pituitary gland

Direct control- nervous system

Anterior Pituitary Gland

(Adenohypophysis) ~75%

Only Endocrine cells

Posterior Pituitary Gland

(Neurohypophysis) ~25%

Only neuron cells

Hypersecretion of hGH

Hypopituitary dwarfism

Hypoglycemia

Hyposecretion of hGH

Giantism (Childhood)

Acromegaly (Adulthood)

Hyperglycemia (Diabetes)

Hyperglycemia

A state characterized by abnormally high levels of glucose (sugar) in the blood

Giantism

Excessive growth hormone secretion in children before the fusion of the long bone epiphyses (growth plates)

Acromegaly

Excess growth hormone secretion in adults after the epiphyseal plates have closed

Parafollicular cells (aka C cells)

Calcitonin

Follicular cells

Thyroglobullin

Triiodothyronine (T3)

Tetraiodothyronine/Thyroxine (T4)

Hypothyroidism (Under-active)

Weight gain, fatigue, cold intolerance, dry skin, constipation, depression, and slow heart rate

Hyperthyroidism (Over-active)

Rapid heart rate, weight loss, heat intolerance, nervousness, sweating, tremors, and insomnia

Grave’s disease

An autoimmune disorder that causes hyperthyroidism (overactive thyroid) by producing antibodies that force the thyroid to make excessive hormones

Hashimoto’s Disease

An autoimmune disorder that causes hypothyroidism (underactive thyroid) by damaging and destroying the gland

Conn’s Syndrome

When the adrenal glands produce excess aldosterone, leading to high blood pressure, low potassium, and often headaches, muscle weakness, or frequent urination

Cushing’s Disease

A serious endocrine disorder caused by long-term production of cortisol by the adrenal glands

Addison’s Disease

A chronic disorder where the adrenal glands don't produce enough cortisol and aldosterone

Type 1 Diabetes

IDDM (Insulin-dependent diabetes mellitus)

Autoimmune disease (beta cells in pancreas are attacked by insulin)

Type 2 Diabetes

IIDM (Insulin-independent diabetes mellitus)

A lot of glucose circulating in the blood

Gestational diabetes

During Pregnancy; can lead to type 2 diabetes but usually goes away