Nervous and Endocrine systems

What is the purpose of the nervous system?

Primary internal communication system

What are the two main functions of the nervous system?

• Collect, process and respond to environmental stimuli

• Coordinate the working of different organs and cells in the body

What two parts is the nervous system broken up into?

• Central nervous system

• Peripheral nervous system

What is the CNS made up of?

Brain and spinal cord

What is the brain’s function?

Gives us conscious awareness and is involved in all psychological processes

What are the four regions of the brain?

• Occipital lobe

• Temporal lobe

• Parietal lobe

• Frontal lobe

What is the function of the occipital lobe?

Processes visual information

What is the function of the temporal lobe?

Processes auditory information

What is the function of the parietal lobe?

Sorts information from different senses and plays an important role in spatial navigation

What is the function of the frontal lobe?

Sorts more complicated functions - planning, abstract reasoning, logic etc

What is the spinal chord?

Extension of the brain

What is the function of the spinal chord?

Passes messages to and from the brain and connects nerves to the PNS. Responsible for reflex actions

What is the function of the PNS?

Relays messages in the form of nerve impulses from the CNS to the rest of the body

What are the two parts the PNS is subdivided into?

• Automatic nervous system

• Somatic nervous system

What does the ANS do?

Transmits information to and from internal bodily organs - it controls vital functions in the body eg breathing, heart rate, digestion, stress response, sexual arousal etc.

What are the two parts the ANS is divided into?

• Sympathetic nervous system

• Parasympathetic nervous system

What does the parasympathetic nervous system do?

Returns body back to ‘normal’ resting state

What does the sympathetic nervous system do?

Prepares body for fight or flight

What does the somatic nervous system do?

Transmits information from receptor cells in the sense organs to the CNS, and receives information from the CNS that directs muscle movement

What are the differences between the endocrine and nervous systems?

1. Endocrine acts more slowly

2. Endocrine causes more widespread and powerful effects

3. Nervous system works through electrical and chemical signals, whereas the endocrine system works with hormones

How does the endocrine system work?

• Glands in the body produce hormones

• Hormones affect target cells and organs

• This regulates bodily function

What are hormones?

Chemical messengers secreted into the bloodstream and affect any cell that has a receptor for that particular hormone - powerful and diverse responses as they affect cells in more than one organ in one go.

What is an example of a hormone in action?

Thyroid produces thyroxine - this increases heart rate, but also increases metabolic rates - overall affects growth rates

What is the master gland?

Pituitary gland

What does the master gland do?

Controls the release of hormones from all of the other glands in the body

How does the endocrine system and the ANS work together during ‘fight or flight’?

• When stress is perceived, the hypothalamus activates the pituitary gland, and this triggers activity in the sympathetic branch of the ANS

• The ANS changes from the parasympathetic state (normal resting) to the sympathetic state (physiologically aroused)

• Adrenaline is released from the adrenal gland, triggering the ‘fight or flight’ response - instant and automatic reaction

• After the threat has passed, the PNS returns the body to its resting state