What is she doing?

What is inside the syringe?

What disease does she has?

InjectionInjection

InsulinInsulin

DiabetesDiabetes

??

??

Regulation of blood glucose levelRegulation of blood glucose level

More insulin is secreted

(1) more glucose is converted to glycogen in liver

(2) more glucose is oxidized in body cells

Less insulin is secreted

(1) more glycogen in liver is converted to glucose

(2) less glucose is oxidized in body cells

Normal blood glucose level

High blood

glucose level

Low blood

glucose level

Blood glucose level falls

Blood glucose level rises

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• chemicals secreted by chemicals secreted by ductless ductless endocrine glands transported in transported in bloodblood

Insulin is a kind of Insulin is a kind of hormonehormone..

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What is Insulin?

What are hormones?

• serve as serve as chemical messengerschemical messengers which act on which act on target organstarget organs and regulate body processes and regulate body processes

e.g. e.g. PancreasPancreas is the endocrine gland producing is the endocrine gland producing insulin.insulin.

e.g. e.g. LiverLiver is the target organ that insulin exerts is the target organ that insulin exerts its effect.its effect.

Transport of hormones:Transport of hormones:

11 secreting cells in endocrine gland secrete hormones

22 hormones diffuse into blood

33 hormones are transported to all parts of the body

44 cells in specific target organs receive hormones and changes occur

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Brief RevisionBrief Revision

1 Hormones are secreted by ________________. They act on specific ______________ and regulate body processes.

endocrine glands

2 The blood glucose level is regulated by two hormones: _______ and _________ . They control the interconversion of _________ and _________.

insulin glucagon

target organs

glucose glycogen

16.9 What are the similarities and differences between hormonal and nervous coordination?

Hormonal coordination

Nervous coordination

Components

Types of message

Transmission route

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Endocrine glands & blood

Neurones, brain & spinal cord

Nerve impulsesHormones

Blood stream Nerve fibres

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Hormonal coordination

Nervous coordination

Response occurs

Speed of transmission

Duration of response

Body processes involved

In more widespread area

Slower Rapid

Usually long lasting Short term

Reflex actions and voluntary actions

Reproduction, growth, etc. always involuntary

Only in places with nerve supply

16.9 What are the similarities and differences between hormonal and nervous coordination?

Pancreas

• produce insulin (胰島素 ) and glucagon (高血糖素 )

• they work together to regulate the blood glucose level

glucose

insulin

glucagonglycogen

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Examples of endocrine glands

Examples of endocrine glands

Ovaries and testes

• produce sex hormones (性激素 ) which

1 stimulate ovaries to release eggs (卵子 ) and testes to make sperm (精子 )

2 responsible for the development of secondary sexual characteristics(第二性徵 )

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16.8 How does hormonal control work?

detector

detector

normal level of factors

higher level of factors than normal

lower level of factors than normal

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by a negative feedback mechanism (負反饋機制 )

negative feedback

balancing action to decrease

the level

balancing action to increase

the level