guided notes for biology unit 1 first part

GCSE GUIDED NOTES BIOLOGY PT 1: NERVES AND HORMONES

In this unit, you will study ways that living things regulate themselves. Two methods of regulation are the nervous system and the hormones. The goal – a relatively balanced environment in the body – is called homeostasis.

THE NERVOUS SYSTEM

What does the nervous system do? _________________________________________________

Structures in the nervous system are composed of nerve cells, or ____________________.

There are three parts to a neurone:

1. _____________________________________________

2. _____________________________________________

3. _____________________________________________

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The __________________ of the neurone is covered by the myelin sheath, which protects the nerve fibres. Fibres with a myelin sheath are said to be myelinated.

____________________ is myelinated, while ____________________ is unmyelinated.

Which can send information faster? ___________

A synapse is ___________________________________________________________________

How does a nervous signal get across a synapse? ______________________________________

These chemicals are called _________________________. An example is __________________.

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The nervous system can be divided into two parts:

1. ___________________________________________

2. ___________________________________________

The central nervous system includes:

1. _____________________________

2. _____________________________

The peripheral nervous system includes:

1. ______________________________

2. ______________________________

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Parts of the brain:The cerebrum, which ____________________________________________________

1. ____________________________

2. ____________________________

3. ____________________________

4. ____________________________

The cerebellum, which ____________________________________________________

The diencephalon, which ___________________________________________________

1. ____________________________

2. ____________________________

3. ____________________________

The brain stem, which _____________________________________________________

1. ____________________________

2. ____________________________

3. ____________________________

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Bundles of nervous fibres in your peripheral nervous system are called nerves. These nerves work to recognize stimuli and carry that information to your brain.

A stimulus is _______________________________________________________________________

We react to stimuli through our sensory organs. These are:

the eyes, which have ____________ receptors that are sensitive to __________ stimuli

the ears, which have ____________ receptors that are sensitive to __________ stimuli

AND ____________ receptors that are sensitive to __________ stimuli

the nose, which have ____________ receptors that are sensitive to __________ stimuli

the eyes, which have ____________ receptors that are sensitive to __________ stimuli

the skin, which have all sorts of receptors that are sensitive to ______________________

Sensory neurones ________________________________________________________________

Relay neurones (or interneurones) ___________________________________________________

Motor neurones __________________________________________________________________

Effectors are _____________________________________________________________________

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Most information goes all the way to your brain for integration. Some responses are automatic – these are called reflexes.

The reflex arc goes ________________________________________________________________

The pathway for a reflex arc is

________ ________ ________ ________ ________ ________ ________

HORMONES

Hormones are another way the body regulates itself.

Hormones are __________________________________________________________________

Hormones are part of the endocrine system.

Endocrine glands secrete ___________________________________________________

as opposed to exocrine glands, which secrete ___________________________________

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Hormones are relatively long-lasting, and the travel through the body at the speed of ____________.

Here are some endocrine glands, and the hormones they produce:

The pituitary gland is located ________________________________________________________

Growth hormone (GH): _______________________________________________________

Follicle-stimulating hormones (FSH): ____________________________________________

Oxytocin: ___________________________________________________________________

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The thyroid is located ______________________________________________________________

Thyroid hormones ___________________________________________________________

The adrenal glands are located ________________________________________________________

Cortisol _____________________________________________________________________

Epinephrine (adrenaline) ______________________________________________________

The pancreas is located ______________________________________________________________

Insulin _____________________________________________________________________

The testes are located _______________________________________________________________

Testosterone ________________________________________________________________

The ovaries are located ______________________________________________________________

Oestrogen __________________________________________________________________

How are hormones and nerves similar?

_________________________________________________________________________________

How do they differ?

Nerves are ___________________, ______________________, and ____________________

Hormones are ________________, ______________________, and ____________________

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One important function of hormones is to regulate reproduction. For males, this involves production of sperm cells. For females, this involves production of egg cells, the menstrual cycle, and maintenance of pregnancy.

The menstrual cycle has four stages:

1. ______________________________________________

2. ______________________________________________

3. ______________________________________________

4. ______________________________________________

These stages line up with the ovarian cycle, which releases a mature egg cell from the ovary.

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Note the hormones involved in the menstrual and ovarian cycles: FSH, LH, oestrogen, and progesterone. These hormones can be used to control a woman’s fertility.

How can oestrogen and progesterone limit fertility? ________________________________

___________________________________________________________________________

The birth control pill uses these hormones to control fertility.

Pros: _______________________________________________________________________

Cons: ______________________________________________________________________

Hormones can also increase fertility. If women have low FSH and LH, these hormones can be injected to stimulate eggs to mature.

Pros: _______________________________________________________________________

Cons: ______________________________________________________________________

PLANT HORMONES

We have been talking about hormones in humans (and other animals), but plants use hormones for regulation, too.

Plant growth hormones are called auxins.

Auxins control growth at ________________________________________

Auxins are produced in _________________________________________

They ______________ growth in the shoot but ______________ growth in the roots

Phototropic means ______________________________________________________________

Geotropic means _________________________________________________________________

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If you have more auxins on one side of a structure, that side will grow faster. So, to grow toward the light, a plant will produce more auxins on the shady side so the plant bends toward the light.

Plant shoots are __________________ phototropic and ___________________ geotropic.

Plant roots are ___________________ phototropic and ___________________ geotropic.

We can make use of plant hormones, by either extracting natural ones or making artificial ones.

How can plant hormones be used commercially?

Weedkillers: ______________________________________________________________

Rooting powder: ___________________________________________________________

Delay ripening: _____________________________________________________________

Control dormancy: __________________________________________________________

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HOMEOSTASIS

What is homeostasis? ________________________________________________________________

How is homeostasis related to our discussion of nerves and hormones? _______________________

_________________________________________________________________________________

Your body maintains homeostasis with the help of feedback mechanisms (or feedback loops). There are negative feedback and positive feedback mechanisms.

Negative feedback works by ___________________________________________________________

Receptor: ___________________________________________________________________

Processing centre: ____________________________________________________________

Effector: ____________________________________________________________________

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What are some things that the body needs to remain constant?

Temperature

The optimal body temperature is about ______________

Receptors for temperature are in the _______________

Body temperature is controlled by the _______________

If you’re too hot: _____________________________________________________________

If you’re too cold: ____________________________________________________________

Blood sugar

You gain sugars by eating foods with ______________________

Some sugar is good for you because ______________________________________________

A hormone called _________________ maintains the right level of sugar in your blood

Water and ions

Water is taken into the body by _________________________________________________

Water is lost through __________________________________________________________

Water levels are balanced by the ______________________

A hormone called ____________________________ maintains the right level of water in your blood

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guided notes for biology unit 1 first part

Documents

gcse guided

growth

geotropic

nervous system

located

cons

myelin sheath

biology pt