Nervous System and Endocrine System Flashcards
Nervous System
Complex network of cells
Functions - collecting, processing and responding to info from environment, & co-ordinating working of different cells and organs
Divided into CNS and PNS
Central Nervous System
Origin of all complex decisions and commands
Divided into brain and spinal cord
Passes messages to and from brain and connects nerves to Peripheral Nervous System
Brain
Centre of all conscious awareness
Human brain contains cerebral cortex, separates us from other animals
Divided into 2 hemispheres
Spinal cord
Extension of brain
Responsible for reflex actions
Peripheral Nervous System
Transmits messages to and from CNS via millions of neurons, divides into ANS and SNS
Autonomic Nervous System
Controls vital functions in the body e.g. breathing, heart rate, digestions
Splits into two systems - Parasympathetic and Sympathetic nervous systems
Somatic Nervous System
Controls muscle movement
Receives info from sensory receptors in body
Endocrine System
Control vital bodily functions
Much slower than nervous system but more widespread and powerful
Glands
Secrete hormones into bloodstream which affects cells with receptor for that hormone
Thyroid Gland
Produces thyroxine, increases heart rate
Pituitary Gland
Main endocrine gland, controls hormone release from all other glands, found in brain
Fight or Flight
Triggers hypothalamus, which signals to pituitary gland, which signals to adrenal gland to produce adrenaline
State changes from parasympathetic, resting state, to sympathetic, fight or flight state
Psychological changes in body are triggered e.g. increased heart rate and breathing rate
After threat passes, the parasympathetic NS returns to resting state, acting as a brake to reduce activity of SNS
Evaluation - ‘freeze’ response
Gray (1998) suggests that first response to danger is to avoid confrontation, and we freeze
We are hyper-vigilant in this state, assessing the situation and our options
Evaluation - maladaptive response
Fight or flight was useful for our ancestors, helping them escape from wild animals and the like, but in the modern day we rarely encounter such threats, meaning that we do not require such an intense response
Fight or flight triggering repeatedly to every stressors can have negative consequences on our health
Fight or flight is therefore a maladaptive response
