BIOPSYCH: The Nervous System and The Endocrine System
The Nervous System
- A specialised network of cells in the human body and our primary internal communication system
What are the two main functions of the nervous system?
1. Collecting, processing and responding to information in the environment
2. Coordinating the work of different organs and cells in the body
What are the two subsystems?
1. Central Nervous System(CNS) - THE BRAIN AND THE SPINAL CORD
- Brain - centre of all conscious awareness
- Cerebral cortex - outer layer of the brain - highly developed in humans
- The brain is divided into two hemispheres
- Spinal cord - extension of the brain - responsible for reflex actions
- Passes messages to and from the brain + connects nerves to the PNS
2. Peripheral Nervous System(PNS)
- Autonomic nervous system(ANS) - governs vital functions such as breathing and heart rate
- Somatic nervous system(SNS) - controls muscle movement and receives info from sensory receptors
The Endocrine System
- Works alongside the nervous system to control important functions in the body
- Acts much more slowly than the NS - but powerful and widespread effects
- Glands produce hormones which are secreted into the bloodstream - they affect any cell that has a receptor for that hormone
- Pituitary gland located in the brain - 'master gland' - controls release of hormones from all over the body
What is Fight or Flight?
- When the body experiences a stressful event, the Endocrine system and ANS work together.
- Hypothalamus triggers activity in the sympathetic branch of ANS
- ANS changes from the parasympathetic to the sympathetic state
- Adrenaline is released from the adrenal medulla into bloodstream
- This increases heart rate/breathing rate etc which creates physiological arousal necessary for the fight or flight response
- This all happens as soon as the stressor is perceived
- Once the threat has passed, body returns to sympathetic state
0 comments