Biopsychology Flashcards
What is the central nervous systems main functions?
To collect, process and respond to information in the environment and to co-ordinate the working of different organs and cells in the body.
What is the human nervous system?
Our primary internal communication system.
What are the two main components of the nervous system?
The Central Nervous System
The Peripheral Nervous System
What does the CNS consist of?
Spinal cord and brain
What does the PNS consist of?
The Somatic and Autonomic nervous system.
What does the Autonomic nervous system consist of?
The Sympathetic and Parasympathetic nervous system.
What is the function of the CNS?
Control behaviour and regulate the body’s physiological processes.
What does the brain do?
Provides concious awareness and is involved in all psychological processes. It consists of many regions which are responsible for different functions.
What are the brains 4 main lobes and their function?
Occipital lobe-processes visual information
Temporal lobe-processes auditory information
Parietal lobe-intergrates info from the different senses and is important in spatial navigation
Frontal lobe-higher order functions eg. planning and logic
What is the cerebellum responsible for?
Balance and co-ordination.
What is the brain stem responsible for?
Connects brain and spinal cord and controls involuntary processes eg. heart-rate
What is the role of the spinal cord?
Transfer messages to and from the brain and the rest of the body. Simple reflex actions that do not involve the brain through reflex archs.
How does a reflex arch work?
Information travels by the sensory input to a sensory neuron and then to the relay neurons in the spinal cord motor which immediately instruct the neurons of a muscle to contract.
What is the role of the Peripheral Nervous System?
Relay messages from the CNS to the rest of the body.
What does the somatic nervous system do?
Facilitates communication between the CNS and outside world.
What is the somatic nervous system made up of?
Sensory receptors that carry information to the spinal cord and brain and motor pathways allow the brain to control voluntarymovement.
What is the role of the somatic nervous system?
Carry sensory information from the outside world to the brain and provide muscle responses via the motor pathways.
What does the autonomic nervous system do?
Auto means self-regulating so workings are unconscious. Important role in homeostatis which maintains intenal processes like body temp, heart rate and blood pressure. Transmits info to and from internal organs.
What is the autonomic nervous system made up of?
Only consists of motor pathways and has two components-the sympathetic and parasympathetic nervous system.
What is the sympathetic nervous system responsible for?
Responses that prepare the body for fight or flight. ‘Fight or flight’
How does the sympathetic nervous system work?
Impulses travel from the sympathetic nervous system to organs in the body to help us prepare for action when we are faced with a dangerous situation.
What is the parasympathetic nervous system responsible for?
Relax the body and return us to our resting state. ‘Rest and digest’
How does the parasympathetic nervous sytem work?
Slows down our heart rate and breathing rate and reduces our blood pressure. Any functions previously slowed are now started again.
What can the SNS and PNS not be?
Active at the same time as they have opposing effects on the same organs.
Similarites between the brain and spinal cord?
Both control involuntary processes.
Differences between the brain and spinal cord?
Brain provides conscious awareness and allows for higher order thinking.
Brain consists of multiple regions responsible for different functions.
Similarites between the somatic/autonomic nervous systems and symapthetic/parasympathetic?
Sympathetic and somatic nervous systems respond to external stimuli. Sympathetic responds by preparing the body via fight or flight and somatic responds by carrying info to the brain and spine.
Differences between somatic/autonomic and sympathetic/parasympathetic nervous systems?
Autonomic has 2 sub-systems whereas somatic has only 1.
Somatic has sensory and motor pathways whereas autonomic only has motor pathways.
Examples of what the sympathetic nervous system does?
Dilates pupils
Increases heartbeat
Decreases saliva production
Inhibits digestion
Inhibits bladder
Examples of what the parasympathetic nervous system does?
Constricts pupils
Slows heartbeat
Stimulates saliva production
Stimulates digestion
Contracts bladder
Why do neurons have different functions?
Depending on its location in the body and its role within the nervous system.
What are the features of a sensory neuron?
Long dendrites
Short axon
Pseudounipolar (one axon split into two branches)
Where are sensory neurons found?
Receptors in the eyes, ears, tongue and skin and carry nerve impulses to the spinal cord and brain, when at the brain they are turned into sensations. However not all reach the brain those which stop at the spine allow for quick reflex actions.
What are the features of a relay neuron?
Many short dendrites
Short or long axon
Multipolar (have one axon and several dendrites)
No myelin sheath
Where are relay neurons found?
Between the sensory input and motor output/response. Found in the brain and spinal cord and allow sensory and motor neurons to communicate.
What are the features of a motor neuron?
Short dendrites
Long axon
Cell body in CNS but long axons form part of the PNS
Multipolar (have one axon but several dendrites)
Where are motor neurons found?
In the Central Nervous System and controls muscle movement. When motot neurons are stimulated they release neurotransmitters that bind to receptors on muscles to trigger a response, which lead to movement.
What do dendrites do?
Recieve signals from other neurons or from the sensory receptor cells. They are typically connected to the cell body.
What is an axon?
Long slender fibre that carries nerve impulses in the form of electrical signals known as action potential, away from the cell body towards the axon terminals where the beuron ends.
What is a myelin sheath?
Surronds an axon and insulates it so the electrical impulses travel quicker down the axon.
What is an axon terminal?
Connects the neuron to other neurons using a process called synaptic transmission.
What is synaptic transmission: When is a neuron in a resting state?
When the inside of the cell is negatively charged compared to the outside.
What is synaptic transmission: What happens when a neuron is activated?
When a neuron is activated by a stimulus the inside of the cell becomes positively charged for a split second causing an action potential to occur. This creates an electrical impulse that travels down the axon towards the end of the neuron.
What is synaptic transmission: What happens when the electrical impulse reach the presynaptic terminals?
It triggers the release of neurotransmitters from vesicles across the synapse.
What is synaptic transmission: What do neurotransmitters combine with?
Receptors on the post synaptic membrane (dendrites) of the next neuron.
What is synaptic transmission: Stimulation of postsynaptic receptors by neurotransmitters results in what?
Either excitation or inhibition of the postsynaptic membrane.
What is synaptic transmission: What is done with the excitatory and inhibitory influences?
The influences are summed and if the net effect on the post synaptic neuron is inhibitory, the neuron will not fire whereas if the net effect is excitatory the neuron will fire.
What is synaptic transmission: What happens when the post synaptic neuron fires?
The chemical message is converted back into an electrical impulse and the process of transmission begins again in this other neuron.
What is synaptic transmission: What does each neurotransmitter do?
Binds to a specific receptors and has specific functions. Eg. acetylcholine is found at each point where a motor neuron meets a muscle and upon its release it will cause muscles to contract.
What is synaptic transmission: What mechanicisms prevent neurotransmitters remaining active in the synapse?
There are re-uptake and enzymatic degradation.
What is synaptic transmission?
When a neuron is in a resting state inside the cell it is negatively charged compared to its surrondings. When a neuron is activated by a stimulus the inside of the cell becomes positevly charged for a spilt second, causing an action potential to occur. This creates an electrical impulse that travels down the axon towards the end of a neuron. When the electrical impulse reaches the synaptic terminals, it triggers the release of neurotransmitters from vesicles across the synapse. The neurotransmitters combine with receptors on the postsynaptic membrane. Stimulation of postsynaptic receptors by the neurotransmitters results in either excitation or inhibition of the postsynaptic membrane. The excitatory or inhibitory influences of binding neurotransmitters are summed and if the net effect on the postsynaptic neuron is inhibitory, the neuron will not fire whereas if the net effect is excitatory the neuron will fire. When the postsynaptic neuron fires the chemical message is converted back into an electrical impulse and the process of transmission begins again in the other neuron. Each neurotransmitter only binds to specific receptors and each have a specialist function. Eg. acetylcholine is found at each pointwhere a motor neuron meets a muscle and upon its release it will cause muscles to contract. Two mechanisms prevent neurotransmitters remaining in the synpase. These are re-uptake and enzymatic degradation.
What can neurotransmitters be?
Excitatory or inhibitory
What are neurons when they are at rest?
Negatively charged compared to their surrondings.
What must a neuron be to fire?
Momentarily become positively charged.
How does a neuron become depolarised?
The excitatory effects of the neurotransmitters binding to the receptors of the post synaptic neuron must reach a threshold (after the excitatory and inhibitory influences of the binding neurotransmitters have been summed through a process of summation.)
What effect does excitatory neurotransmitters have?
Depolarising effect on the postsynaptic neurons receptive membrane.
What are depolarising effects known as?
EPSPs because they increase the likelihood that the postsynaptic neuron will fire.
What effect does inhibitory neurotransmitters have?
Hyperpolarising effect on the postsynaptic neurons receptive membrane.
What are hyperpolarising effects known as?
IPSPs because they decrease the likelihood that the postsynaptic neuron will fire.
What happens if the net effect of the binding neurotransmitter on the post synaptic neuron is inhibitory?
If the threshold is not met then the post synaptic neuron will not fire.
What happens if the net effect of the binding neurotransmitter on the post synaptic neuron is excitatory?
If the threshold is met then the post synaptic neuron will fire.
What is an action potential?
An electrical potential
What is the cell body?
Control centre of the neuron.
What are the nodes of ranvier?
Gaps in the myelin sheath that speed up the electrical impulse.
Why can neurons only transmit information in one direction at the synapse?
The synaptic vesicles containg the neurotransmitters are only present on the presynaptic neuron and the receptors are only on the postsynaptic neuron. It’s the binding of the neurotransmitter to the receptor that enable the info to be transmitted to the next neuron. Diffusion of the neurotransmitters mean theycan only go from high to low concentration so can only travel from the presynaptic neuron to the post synaptic neuron.
What does the endocrine system work alongside?
Nervous system
What is the endocrine system?
A network of glands across the body that secrete chemical messages called hormones.
How does the endocrine system transmit information?
This system uses blood vessels.
What do different hormones do?
Produce different effects.
What does each gland produce?
Different hormones
What is a hormone?
Chemical signals which are secreted from the glands into the blood stream to a specific target organ where they influence behaviour and mood.
What is the hypothalamus connected to?
Pituitary gland
What is the hypothalamus responsibe for?
Stimulating or controlling the release of hormones from the pituitary gland. It is the control system which regulates the endocrine system.
What is the pituitary gland responsible for?
The hormones released by the pituitary gland control and stimulate the release of hormones from other glands in the endocrine system.
What is the pituitary gland divided into?
The anterior and posterior lobes which release different hormones.
What does the posterior lobe release?
Oxytocin which is responsible for uterus contractions during childbirth.
What does the anterior lobe release?
Adrenocortial trophic hormone (ACTH) which stimulates the adrenal cortex and the release of cortisol, during the stress response.
What is the pineal gland responsible for?
Releasing melatonin which is important for biological rhythms such as the sleep-wake cycle.
What is the thyroid gland responsible for?
Releasing thyroxine which is responsible fore regulating metabolism.
What is the adrenal gland divided into?
The adrenal medulla and the adrenal cortex.
What is the adrenal medulla responsible for?
Releasing adrenaline and noradrenaline, which is key in the fight or flight response.
What is the adrenal cortex responsible for?
Releasing cortisol which stimulates the release of glucose to provide the body with energy while suppressing the immune system.
What are the testes responsible for?
Releasing androgens including testosterone which is responsible for the development of the male sex characteristics and promotes muscle growth.
What are the ovaries responsible for?
Releasing oestrogen which controls the regulation of the female reproductive system including the menstrual cycle and pregnancy.
What effect does the endocrine system have in comparison to the nervous system?
A longer lasting effect but it is a slower response.
When someone enters a potentially stressful situation what is activated?
Amygdala
What does the amygdala respond to?
Sensory input and connects sensory input with emotions associated with the fight or flight response.
What does the amygdala do in a stressful situation?
Sends a distress signal to the hypothalamus.
How does the hypothalamus communicate with the body?
Via the sympathetic nervous system.
If a situation requires a short term response what is activated?
The sympathomedullary pathway (SAM pathway) is triggered activating the fight or flight response.
What happens when a person enters a dangerous/stressful situation?
The amygdala is activated which sends a distress signal to the hypothalamus.
What happens after the amygdala is activated which sends a distress signal to the hypothalamus?
The hypothalamus activates the SAM pathway which runs to the adrenal medulla and the sympathetic nervous system.
What happens after the hypothalamus activates the SAM pathway which runs to the adrenal medulla and the sympathetic nervous system.
The sympathetic nervous system stimulates the adrenal medulla, part of the adrenal galnd.
What happens after the sympathetic nervous system stimulates the adrenal medulla?
The adrenal medulla secrets the hormones adrenaline and noradrendaline into the bloodstream.
What happens after the adrenal medulla secrets the hormones adrenaline and noradrendaline into the bloodstream?
Adrenaline cause a number of physiological changes to prepare the body for fight or flight.
What physiological changes are cause by the sympathetic nervous system in preperation for the fight or flight response?
Increased heart rate, increased breathing rate, pupil dilation, sweat production and reduction of non-essential functions.
Why does our heart rate increase during fight or flight?
To increase blood flow to organs and increase the movement of adrenaline around the body.
Why does our breathing rate increase during fight or flight?
To increase oxygen intake.
Why do our pupils dilate during fight or flight?
To increase light entry into the eye and enhance vision.
Why does sweat production increase during fight or flight?
To regulate temperature.