Nervous vs. Endocrine System Responses

Nervous vs. Endocrine System Responses

• Nervous system responses are faster due to the complex network of interconnected branches.
• Endocrine system responses are slower as hormones must travel through the bloodstream.

Hormone Definition

• Hormones are chemical messengers that stimulate specific functions in glands or cells.
• ADH (antidiuretic hormone) is an example; it regulates water reabsorption in the kidneys.

Blurred Distinction Between Systems

• Both systems use chemical signals to trigger responses.
• Both are influenced by the hypothalamus.
• Both involve parasympathetic and sympathetic nervous system pathways.
• Both contribute to homeostasis.

Berthold's Rooster Experiment

• The experiment demonstrated endocrine gland function.
• Details of the experiment are not provided.

Endocrine System Research Challenges

• The complexity of hormone pathways is challenging to researchers.

Hormone Study Technologies

• Details of the technologies are not provided.

Hormone Groups & Interactions

• Protein hormones are water-soluble; they interact with cell surface receptors using a secondary messenger.
• Steroid hormones are lipid-soluble; they interact with intracellular receptors.

Hormone-Target Cell Stimulation

• Hormones bind to receptor sites, stimulating a response in target cells.

Gland Hormone Secretion

• Thyroid gland - thyroxine
• Anterior pituitary - human growth hormone (hGH), TSH (thyroid-stimulating hormone).
• Adrenal glands - cortisol
• Pancreas - insulin, glucagon

ADH Regulation (Negative Feedback)

• ADH maintains homeostasis by regulating water levels in the body.
• Negative feedback mechanisms exist to ensure appropriate levels are maintained avoiding over-dehydration.

Tropic Hormones

• Tropic hormones stimulate other glands to produce hormones.
• Anterior pituitary hormones are regulated by releasing hormones from the hypothalamus.

Anterior vs. Posterior Pituitary

• Posterior pituitary stores hormones produced by the hypothalamus.
• Anterior pituitary triggers hormone production in target glands.

hGH Effects

• Gigantism (excess in childhood)
• Dwarfism (insufficiency in childhood)
• Acromegaly (excess in adulthood)

Thyroid Gland as a Thermostat

• Thyroid hormones regulate metabolism by affecting heart rate and energy consumption.

Thyroxine Role

• Thyroxine regulates metabolism, heart rate, and brain development.

Hypothyroidism & Goiter

• Hypothyroidism results from insufficient thyroid hormone.
• Iodine deficiency can lead to goiter (thyroid gland enlargement).

Fight-or-Flight Response

• The body's stress response preparing for action (fight or flight in case)

Hypothalamus & Stress Response

• The hypothalamus stimulates the anterior pituitary to release hormones in response to stress.

Short-Term vs. Long-Term Stress Responses

• Short-term effects include increased heart rate, nausea, butterflies, dilated blood vessels, and increased blood pressure
• Long-term effects include weakened immune system.

Cortisol and Glucose Regulation

• Cortisol converts proteins into glucose, increasing glucose availability for cells.

Chronic Cortisol Effects

• Chronic cortisol leads to elevated blood pressure, blood sugar, etc., leading to health risks.

Aldosterone & Blood Pressure

• Aldosterone enhances water reabsorption into the bloodstream, increasing blood pressure.

Addison's Disease

• Addison's disease is associated with fatigue, hyperpigmentation, and abdominal discomfort.

Islets of Langerhans Cells

• Alpha cells secrete glucagon (raises blood sugar).
• Beta cells secrete insulin (lowers blood sugar).

Insulin & Glucagon in Homeostasis

• Insulin lowers blood sugar levels.
• Glucagon raises blood sugar levels, restoring homeostasis.

Diabetes Mellitus Symptoms

• Symptoms include increased urination, thirst, and blurred vision.

Hyperglycemia

• High blood glucose levels.

Untreated Diabetes Effects

• Untreated diabetes can cause complications such as blindness, kidney issues, and pain in the extremities.

Type 1 vs. Type 2 Diabetes

• Type 1 diabetes is an autoimmune disorder affecting the pancreas.
• Type 2 diabetes is related to insulin resistance.

Type 2 Diabetes Risk Factors

• Factors include lifestyle, family history, and other risk factors.

Banting & Best's Contribution

• Banting and Best discovered insulin and treatments for regulating blood sugar.

Blood Glucose Monitoring in Diabetes

• Methods for monitoring blood glucose levels in people with diabetes.