The Endocrine System

Front 1

What is regarded as the controlling centre of the endocrine system?

Back 1

The hypothalamus-pituitary axis

Front 2

Why is the hypothalamus-pituitary axis considered the controlling centre of the endocrine system?

Back 2

It receives a variety of hormonal, neural, and other stimuli and responds by sending out hormones to the pituitary system

Front 3

What hormones does the anterior pituitary gland release?

Back 3

ADCH, TSH, growth hormone, follicle stimulating hormone

Front 4

What uses the portal venous system to send hormones to the anterior pituitary?

Back 4

The hypothalamus

Front 5

What produces and stores oxytocin and ADH in the posterior pituitary?

Back 5

The hypothalamus

Front 6

By what does the hypothalamus send hormones to stimulate the posterior pituitary?

Back 6

A neural connection

Front 7

What are the main physiological effects of growth hormone on growth?

Back 7

- increases protein synthesis
- increases the amount of cartilage
- activating osteoblasts

Front 8

What are the main physiological effects of growth hormone on metabolism?

Back 8

- increases circulating blood glucose
- induces an insensitivity to insulin

Front 9

What are the clinical manifestations of hyper-secretion of growth hormone?

Back 9

- enlarged organs
- enlarged facial features
- excess growth in length of bones at the epiphyseal plates (children)
- excess glucose in the blood and insulin resistance (hyperglycemia) (diabetes mellitus)
- glucose in the urine (kidneys cannot reabsorb all the glucose
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Front 10

What are the clinical manifestations of hypo-secretion of growth hormone?

Back 10

- decrease in protein synthesis
- decrease in activation of osteoblasts (short stature in children)
- decrease in formation of cartilage (under-developed organs)
- decrease insensitivity to insulin
- decrease in blood glucose levels
- increased susceptibility to hypoglycemia in times of stress

Front 11

What is "insulin resistance"?

Back 11

The body's cells, which need glucose, are not responsive to the insulin produced by the pancreas.

Front 12

How can someone become resistant to endogenous insulin?

Back 12

- insulin doesn't bind to receptors properly due to a change in structure
- the second messenger in decreasing blood glucose does not work properly: does not send a message to the nucleus to upregulate glucose transport carriers to bring glucose into the cell and out of the bloodstream

Front 13

What physiological actions do the mineralocorticoids have?

Back 13

- save salt (Aldosterone) and in the process waste potassium and sodium and potassium are proportional to one another in the body
- ADH also saves water

Front 14

What physiological actions do the glucocorticoids have?

Back 14

- main action is to increase blood glucose levels

Front 15

How do the glucocorticoids increase blood glucose levels?

Back 15

- breaking down proteins and using them as energy supply
- examples of proteins that are broken down include blood vessels and skin

Front 16

What physiological actions do the androgens have?

Back 16

- androgens are anabolic steroids that mainly act to build muscles
- excess in females causes masculinisation: chin hair, excess hair in unwanted places, and enlargement of the clitorus

Front 17

What physiological actions does adrenaline have?

Back 17

- increases heart rate
- dilates pupils
- creates coldness in the extremities

Front 18

Using a flow chart including negative feedback mechanisms, explain why a female with congenital adrenal hyperplasia demonstrates virilisation of the genitals.

Back 18

Front 19

Draw a flow chart depicting the adrenal cortex and the stress response.

Back 19