S2 L5-Control: homeostasis and the Endocrine system

What is homeostasis?

A dynamic process mailing the internal environment, within defined limits, irrespective of the external environment.

How is homeostasis maintained?

By the interaction of the receptor, control centre and effector

How does homeostatic imbalance occur?

When the receptor, effector and control centre fail to respond appropriately

Homeostatic imbalance is a major contributory factor in the development of many…. And the ageing process?

Diseases, the ageing process

What is negative feedback in homeostasis?

When a air bale triggers a counter acting response in order to go back to a set point, to keep homeostasis.

What is positive feedback in homeostasis?

The variable is intensified to make deviation greater.

What does the endocrine system do?

Senses and reacts appropriately to changes inside and outside the body.

What is William Baylis known for?

• The Brown Dog Affair

• “Neurone or “neuron”

What are the main endocrine glands?

• Pineal gland

• Pituitary gland (posterior and anterior)

• Thyroid gland

What does the Pineal Gland do?

• Produces melatonin

• Important for sleep patterns

• Regulation of reproductive hormones

What does the posterior Pituitary gland do?

produces 2 hormones

Oxytocin and Antidiuretic (ADH) hormone

What does the anterior pituitary gland do?

Produce 5 different types of hormones

• Growth hormone (GH)

• Prolactin (PRL) : produces milk

• Follicle-stimulating hormone (FSH) + Luteinizing hormone (LH) : controls production of testosterone and estrogen

• Thyrotropic hormone (TSH)

• Adrenocorticotropic hormone (ACTH)

What happens in the thyroid gland?

Produces thyroxine, triiodothyronine and calcitonin hormone

What does the thyroid gland effect?

Effects on metabolism, bone growth and blood calcium

Where is the parathyroid gland located?

Behind the thyroid gland

Where does the thymus gland play a major role?

In the immune system

What is the purpose of the thymus gland?

Secretes thymus in, which is essential for T cell formation.

What does the adrenal gland do?

• produces adrenaline

• Responds to immediate stress (flight or fight)

What is the function of the pancreas?

Blood glucose regulation

In the pancreas, alpha helix proteins os islets of Langerhans secrete….?

Glucagon

In the pancreas, beta pleated protein sheets os islets of Langerhans secrete….?

Insulin

What are the testes function?

Produces and secretes testosterone

What is a steroid?

Hormones that permanently changes your body.

What is testosterone important for?

For the development of male sex characteristics

What do the ovaries produce?

Produces oestrogen and progesterone

What is the hormone human chorionic gonadrotrophin?

First hormone that is produced early on in pregnancy that appears on a pregnancy test.

What does the placenta produce?

Produces hormones temporarily but produces oestrogen and progesterone later on in pregnancy

What can the production of secreting hormones do?

Cause nervous stimulation

What are the 2 types of hormones?

Lipid-soluble and water soluble.

What is n example of a lipid-soluble hormone?

Steroid hormones- that is cholesterol based

Steroid hormone are based on ….. core structure.

Cholesterol

What a re endocrine disorder examples?

• diabetes

• Fertility levels