Biopsychology (AS) Flashcards
What is the nervous system?
- The nervous system is a specialised network of cells in the human body and is our primary internal communication system
- It is based on electrical and chemical signals
- The nervous system has 2 main functions:
-> to collect, process, and respond to information in the environment
-> to coordinate the working of different organs and cells in the body - The nervous system is divided into two main components, which are the central nervous system and the peripheral nervous system
Outline the central nervous system
Brain:
- Provides conscious awareness and is involved in all psychological processes
- The brain receives information from sensory receptors, and sends messages to muscles and glands in the body
Spinal cord:
- The spinal cord transfers messages to and from the brain and the rest of the body
- The spinal cord is an extension of the brain
- It connects nerves to the PNS and is responsible for reflex actions
Similarities:
- The brainstem and spinal cord both control involuntary processes, for example the brain stem controls breathing, and the spinal cord controls involuntary reflexes
Differences:
- The brain provides conscious awareness and allows for higher order thinking, while the spinal cord allows for simple reflex responses
- The brain consists of multiple regions responsible for different functions, whereas the spinal cord has one main function
What is the function of the brain stem?
The brain stem connects the brain and spinal cord, and controls involuntary processes, such as breathing.
Outline the peripheral nervous system
- The role of the peripheral nervous system is to relay messages from the central nervous system to the rest of the body
- The peripheral nervous system consists of two main components, which are the somatic nervous system and the autonomic nervous system
Somatic nervous system:
- The somatic nervous system maintains communication between the central nervous system and the outside world
- The somatic nervous system is made up of sensory receptors that carry information to the spinal cord and brain, and motor pathways that allow the brain to control movement
- The role of the somatic nervous system is to carry sensory information from the outside world to the brain and provide muscle responses via the motor pathways
Autonomic nervous system:
- Plays an important role in homeostasis, which maintains and balances internal processes, like body temperature, heart rate, and blood pressure
- The autonomic nervous system consists of only motor pathways
- It has two components, which are the sympathetic nervous system and the parasympathetic nervous system
Sympathetic nervous system:
-> The sympathetic nervous system is typically involved in responses that prepares the body for fight or flight
-> Impulses travel from the sympathetic nervous system to organs in the body for action when we are faced with a dangerous situation
-> For example, our heart rate, blood pressure, and breathing rate increase while less important functions such as digestion, salivation, and urination decrease
Parasympathetic nervous system:
-> The role of the parasympathetic nervous system is to relax the body and return us to a ‘normal’ resting state
-> Consequently, the parasympathetic nervous system slows down our heart rate and breathing rate and reduces our blood pressure
-> Furthermore, any functions that were previously slowed down during the fight or flight reaction are started again, for example, digestion
Similarities:
- The sympathetic nervous system and the somatic nervous system both respond to external stimuli
Differences:
- The autonomic nervous system consists of two subcomponents, whereas the somatic nervous system only has one
- The somatic nervous system has sensory and motor pathways, whereas the autonomic nervous system only has motor pathways
- The autonomic nervous system controls internal organs and glands, while the somatic nervous system controls muscles in movement
What is homeostasis?
- Homeostasis is any self regulating process by which an organism tends to maintain stability while adjusting to conditions that are best for survival
- If homeostasis is successful, life continues, but if it’s unsuccessful, it result in a disaster or death of the organism
What are the sympathetic nervous system responses?
- Dilated pupils
- Increased heart rate
- Decreased saliva production
- Inhibited digestion
- Inhibited bladder contraction
- Inhibited peristalsis and secretion
- Stimulated glucose production and release
- Secretion of adrenaline and noradrenaline
What are the parasympathetic nervous system responses?
- Stimulated bladder
- Stimulated saliva production
- Stimulated digestion
- Slowed heart rate
- Constricted pupils
- Stimulate bile release
- Constricted bronchi
- Stimulate peristalsis and secretion
Give an example of how the nervous system works
Scenario: the bell rings, and the students start packing up their bags.
Analysis: the sound of the bell ringing is picked up by the students ears and is transmitted via the peripheral nervous system to the brain (a sensory message). The brain recognises the sound as a bell and interprets it as a signal that the lesson is ended. To fulfil the goal of packing up and going elsewhere, the brain sends out a large number of messages via the somatic nervous system. These motor messages are carried by the spinal cord to the skeletal muscles, where they result in movements that allow the students to pick up their belongings. Throughout this process, the brain relies on visual sensory input via the peripheral nervous system in order to identify the locations of objects, decide whether their personal possessions and coordinate the control of the muscles in order to ensure that movements are accurate.
What is the endocrine system?
- The endocrine system works alongside the nervous system
- It is a network of glands across the body that secrete chemical messages called hormones
- Instead of using nerves to transmit information, this system uses blood vessels
- Different hormones produce different effects/behaviours
What are glands?
- The endocrine system is a network of glands across the body that secretes chemical messages called hormones
- The pituitary gland is sometimes known as the master gland, because the hormones released by the pituitary gland control and stimulate the release of hormones from other glands in the endocrine system
What are hormones?
Hormones are chemical substances that regulate the activity of cells or organs in the body.
How do glands and hormones work?
- The hypothalamus sends releasing hormone to the pituitary gland
- Pituitary gland secretes a stimulating hormone
- The target gland releases its hormone
- Levels of the target glands hormone in the bloodstream increases
- The hypothalamus stops secreting the releasing hormone
- The pituitary gland stops secreting a stimulating hormone
- The target gland stops releases its hormone
Outline the roles of the different glands and their hormones
Hypothalamus:
- The hypothalamus is connected to the pituitary gland, so no hormones are released
- The hypothalamus is responsible for stimulating and controlling the release of hormones
- It is the control system of the endocrine system
Pituitary gland:
- The pituitary gland is known as the master gland
- The pituitary gland has two lobes, which are the anterior lobe and the posterior lobe
- The hormones released by the pituitary gland control and stimulate the release of hormones from other glands
- The anterior lobe releases ACTH, which stimulates the adrenal cortex
- The posterior lobe releases oxytocin, which is responsible for contractions during childbirth
Thyroid:
- The thyroid gland releases thyroxine, which is responsible for regulating metabolism
Pineal gland:
- The pineal gland releases melatonin, responsible for the circadian rhythm
Adrenal gland:
- The adrenal gland is made up of the adrenal medulla and the adrenal cortex
- The adrenal medulla releases adrenaline and noradrenaline, which play a key role in fight or flight
- The adrenal cortex releases cortisol, which stimulates the release of glucose, which provides the body with energy while suppressing the immune system
Pancreas:
- The pancreas releases insulin, which controls glucose levels in the body
Ovaries:
- The ovaries release oestrogen, which controls the regulation of the female reproductive system, including the menstrual cycle and pregnancy
Testes:
- The testes release testosterone, which is responsible for the development of male sex characteristics during puberty and also helps muscle growth
Outline the fight or flight response
The fight or flight response is also known as the sympathomedullary pathway.
- When an individual is faced with a threat, the amygdala is mobilised
- The amygdala than sends a distress signal to the hypothalamus, which then functions like a command centre in the brain
- The hypothalamus triggers the autonomic nervous system to its sympathetic state
- The pituitary gland releases ACTH, which causes the adrenal medulla to release adrenaline into the bloodstream, leading to physical changes:
-> increased heart rate to increase blood flow to organs and increase the movement of adrenaline around the body
-> increased breathing rate to increase oxygen intake
-> dilated pupils to increase light intake and vision, especially in the dark
-> sweat production to regulate temperature
-> reduction of non-essential functions, like the digestive system, urination, and salvation to increase energy for other essential functions - Once the threat has passed, the parasympathetic nervous system returns the body to its resting state
Evaluate the fight or flight response
One limitation to the fight or flight response is that human behaviour is not limited to only two responses. Gray (1988) suggests that the first response to danger is to avoid it all together, which is demonstrated by a ‘freeze’ response. During the freeze response, humans are hypervigilant while they appraise the situation to decide the best course of action. This suggests that the fight or flight explanation of behaviour is limited and doesn’t fully explain the complex cognitive and biological factors that underpin human responses to stress/danger.
Another issue with this explanation is that it doesn’t fully explain the stress response in females. Taylor et al suggests that females adopt a ‘tend and befriend’ response in stressful/dangerous situations. Women are more likely to protect their offspring and form alliances with other women rather than fight an adversary or flee. This highlights a beta bias within this area of psychology: psychologists assumed that females responded in the same way as males until Taylor suggested otherwise. Therefore, while the original fight or flight explanation might have been limited in its application to females, it has prompted more recent research which has provided an alternative explanation more relevant to females, which is actually a strength.
A final concern with the fight or flight response is that it can have a negative/detrimental effect on health, especially in modern day life. While it may have been a useful survival mechanism for ancestors who faced genuinely life-threatening situations, for example from predators, modern day life rarely requires such an intense biological response. This matters because the activation of this response can increase blood pressure, cause damage to blood vessels, and contribute to heart disease. This suggests that the fight or flight response is a maladaptive response to contemporary life.
