biopsychology: The nervous system

Question 1

what is the nervous system?

Answer 1

• A specialised network of cells in the human body and is our primary internal communication system. It is based on electrical and chemical signals whereas the endocrine system is based on hormones.

Question 2

what are the two main functions of the nervous system?

Answer 2

• The nervous system has two main functions:
1. To collect, process and respond to information in the environment.
2. To co-ordinate the working of different organs and cells in the body
• Nervous system is divided into the Central Nervous System (CNS) and the Peripheral Nervous System (PNS)

Question 3

what is the central nervous system?

Answer 3

• Made up of brain and spinal cord.
  
  • Brain is the centre of all conscious awareness and is divided into two hemispheres.
  • The spinal cord is an extension of the brain. It passes messages from the brain and connects nerves to the PNS. It is also responsible for reflex actions such as pulling your hand away from a hot plate.

Question 4

what is the peripheral nervous system?

Answer 4

• The PNS transmits messages to and from the central nervous system. The peripheral nervous system is subdivided into:
• The automatic nervous system (ANS)- governs vital functions in the body such as breathing, heart rate, arousal and stress response.
Somatic nervous system (SNS)- governs muscle movement and receives information from sensory receptors.

Question 5

what is the endocrine system?

Answer 5

• The endocrine system works along side the nervous system to control vital functions in the body.
  
  • Various glands produce hormones which are secreted into the blood stream, they affect any cell in the body that has a particular receptor for that hormone.
  • For example, thyroid gland produces thyroxine which affects the cells in the heart and also increases metabolic rate.
  • The key endocrine gland is the pituitary gland located in the brain, it controls the release of hormones from all the other endocrine glands in the body.

Question 6

how do the endocrine system and ANS work together?

Answer 6

• Often the endocrine system and ANS work parallel with one another
  
  • When a stressor is perceived the hypothalamus activates the pituitary gland, this triggers activity in the sympathetic branch of the ANS.
  • The ANS changes from its normal resting state (parasympathetic state) to the physiologically aroused sympathetic state.

Question 7

what are the 3 stages of fight or flight?

Answer 7

Adrenaline- stress hormone adrenaline is released from the adrenal medulla into the blood stream. Adrenaline triggers physiological changes in the body which created the physiological arousal necessary for the fight or flight response.

Immediate and automatic - all of this happens as soon as a threat is detected. This is an acute response an automatic reaction in the body. Physiological changes associated with a sympathetic response include; increased heart rate, increased breathing rate, dilated pupils e.c.t.

Parasympathetic action- Once the threat has passed the PNS returns the body to its normal resting state. The parasympathetic system acts as a ‘brake’ and reduces the activities of the body that were increased by the actions of the sympathetic branch. Sometimes referred to as the rest and digest p