Biopsychology Flashcards
The nervous system
A network of nerve cells that transmit messages between different parts of the body, allowing communication to take place
Two main parts are the central nervous system and the peripheral nervous system.
The CNS and its components
CNS
- made up of the brain and spinal cord
- brain provides conscious awareness and is involved in all psychological processes
- brain consists of many regions which are responsible for different functions
- the spinal cord is an extension of the brain and is responsible for reflex actions
The PNS and its components
PNS
The role of the PNS is to relay messages from the CNS to the rest of the body
Consists of the somatic nervous system and the autonomic nervous system
Somatic nervous system
- role is to carry sensory info from outside world to the brain and provide muscle responses via motor pathways
Autonomic nervous system
- plays important role in homeostasis which maintains internal environment
- has two components: the sympathetic and parasympathetic nervous system
The sympathetic and parasympathetic nervous system
sympathetic
- involved in responses preparing body for fight or flight
- impulses travel from somatic nervous system to organs to help prepare the body for action
- eg. Heart rate, breathing and blood pressure increases and less important functions like digestion are suppressed
parasympathetic
- role is to relax the body and return us to our ‘normal’ state
- slows heart rate, breathing and lowers blood pressure
- any functions that were slowed during a fight or flight response are started again
The endocrine system
- works along side the nervous system to control vital functions
- hormones are secreted into the blood stream and affect any cell that has a receptor cell for that hormone
- most hormones affect cells in several organs or throughout the entire body
The endocrine system - fight or flight
- endocrine system and autonomic nervous system work in parallel
- eg. When a stressor is perceived the hypothalamus activates the sympathetic branch of the ANS. The ANS changes from its resting state to physiologically aroused state. Stress hormone adrenaline is released from the adrenal gland which triggers physiological changes within the body (increased heart rate) which creates the physiological arousal necessary for fight or flight
- happens in an instant as soon as threat is detected
- once threat has passed parasympathetic nervous system returns body to normal resting state
The endocrine system- glands and hormones
- hypothalamus
- pituitary gland
- pineal gland
- thyroid gland
- adrenal gland
- ovaries
- testes
Hypothalamus
Effect - stimulates and controls release of hormones from pituitary gland
pituitary gland
Anterior - ACTH
effect - stimulates the adrenal cortex and the release of cortisol during the stress response
Posterior - oxytocin
Effect - responsible for uterus contractions
penial gland
Melatonin
Effect - responsible for important biological rhythms including sleep wake cycle
thyroid gland
Thyroxine
Effect - regulates metabolism
adrenal gland
Adrenal medulla - adrenaline and noradrenaline
Effect - key hormones in fight or flight
Adrenal cortex - cortisol
Effect - stimulate release of glucose whilst suppressing immune system
ovaries
Oestrogen
Effect - control the regulation of female reproductive
testes
Testosterone
Effect - responsible for development of male sex characteristics
Neurons and synaptic transmission - key terms
- neurons
- Motor neurons
- Sensory neurons
- Relay neurons
Neurons- basic building blocks of nervous system, nerve cells that process and transmit messages via electrical and chemical signals
Motor neurons - connect central nervous system to factors (short dendrites and long axons)
Sensory neurons - carry messages from peripheral nervous system to central nervous system (long dendrites and short axons)
Relay neurons - connect to sensory to motor neurons (short dendrites and short axons)
Neurons and synaptic transmission - parts of a neuron
- Nucleus
- dendrites
- axon
- Myelin sheath
- Node of renvier
- Axon terminals
Nucleus- contains genetic material
Dendrites - branch structures carry impulses from neurons towards body
Axon - carries impulses down cell body down the neuron
Myelin sheath - protects axon and speed up electrical transmission of the impulse
Node of Renvier - gaps between myelin sheath
Axon terminals - communicate with next neuron across the synapse
Neurons and synaptic transmission - electrical transmission
- when neuron is resting inside of cell is negatively charged
- When activated by stimulus cell becomes positively charged for a second causing action potential to occur
- Creating an electrical impulse that travels down the axon
Neurons and synaptic transmission - synaptic transmission
- neurons communicate in groups → neural networks
- synapse is gap between neurons
within the neuron, signals transmit electrically. But between neurons they’re transmitted chemically across synapse
- when electrical impulse reaches end of neuron ( the pre synaptic terminal) it triggers release of neurotransmitters from synaptic vesicies
- once neurotransmitter crosses gap, its taken up by post synaptic receptor sites (dendrites of the next neuron)
- here the chemical message is converted back into an electical impulse
Neurons and synaptic transmission- neurotransmitters
- chemicas that diffuse across synapse to next neuron
- each neurotransmitter has own specific structure that fits into a post synaptic receptor site
- they have specialist functions
