8 - The Endocrine System Flashcards
The endocrine system
Is a series of glands that produce and secrete hormones that the body uses for a wide range of functions
Bodily functions that the endocrine function helps with
- respiration
- metabolism
- reproduction
Helps to play an important role in homeostasis because hormones regulate activity of the body cells
Homeostasis
The ability of the body to maintain a stable internal environment despite changes in external conditions
Hormones
Molecules that signal a target cell to “do something”
Label the location of the major endocrine organs in the human body
- hypothalamus
- pituitary gland
- pineal gland
- thyroid gland
- Thymus
- adrenal gland
- pancreas
- ovaries
- testes
Role of the pineal gland
Secretes melatonin
Role of the hypothalamus
Responsible for the metabolic process
Role of the pituitary gland
Senses the bodies needs and sends signals
Role of the thyroid gland
Metabolism, growth, heart, digestive function
Role of the adrenal gland
Enables the body to deal with stress and controls energy
Role of the pancreas
- AIDS in food digestion
- controlling energy levels of blood
Role of the ovaries
Produces eggs
Role of the testes
Produces Sperm
Circulating hormones
Travel around the body in the blood.
Examples: Adrenaline and testosterone
Local hormones
Act on neighboring cells without entering the bloodstream and are usually inactivated quickly.
Examples: glucagon and Seratonin
The release of hormones
Release of most hormones occur in short bursts yet some occur over long periods of time in order to stimulate permanent changes in the body
What do hormones affect
Hormones effect only specific target cells by chemically binding to specific receptors
Hormones are secreted by endocrine glands to regulate and coordinate a range of bodily functions
Explain how circulating hormones are regulated
- signal from the nervous system such as adrenaline
- chemical changes in the blood such as insulin
- other hormones such as growth hormones
Explain the relationship between the hypothalamus and the pituitary gland
- both responsible for maintaining homeostasis
- both apart of the brain
- the pituitary is located under the hypothalamus
- the hypothalamus controls the pituitary gland
- Neurohormones from the hypothalamus directly affect the pituitary gland
- nerve impulses from the hypothalamus also stimulate the pituitary gland
The pituitary gland secretes growth hormones that help regulate a wide range of bodily functions including growth, water and temperature regulation
Positive feedback loops
- when a product of a reaction leads to an increase in that reaction / reinforce or increase changes in controlled conditions
- an event will occur to discontinue the feedback
- generally control infrequent conditions
Examples: Urine contractions / childbirths
Negative feedback loops
When a product of a reaction leads to a decrease in that reaction / reverse system in the controlled condition / brings the body back to balance
Example: most feedback mechanism s regulate hormones in the human body
Adrenaline
It’s job
It’s effects
Increase heart rate
- prepares the body for a flight or fight response
- increase heart rate
- increase blood pressure
- dizziness
- enlarging pupils
- tunnel vision
- hearing loss
- slow digestion
- shaking
- dry mouth
Nor-adrenaline
Decreases heart rate
What is ADH and it’s function
Anti-diuretic
Hormones helps to control blood pressure by acting in the kidneys and he blood vessels. It’s most important role is to conserve the fluid volume of your body by reducing the amount of water passed out in urine
When someone is dehydrated ADH will absorb more water
