Biopsychology (AS) Flashcards
Define a neuron
A specialised cell of the nervous system
Define Synapse
Gaps between two neurons, which an impulse travels across
Define neurotransmitter
Chemical substance that helps the chemical messengers across the synaptic cleft
Define a sensory neuron
Describe its specialisation in structure
Transmits impulses from a receptor (5 senses), to the CNS
Structure:
- Has receptors
- The cell body and nucleus sticks out the side
Define a Relay neuron
Describe its specialisation in structure
Nerve cell in the CNS which passes signal between the sensory and motor neurons
Structure:
- Much shorter than the other neurons
Define a motor neuron
Describe its specialisation structure
Nerve cell that carries electrical impulses from the CNS to the muscle fibres (effector)
Structure:
- Motor=movement
- Muscle fibres at the end of the motor neuron
Define fight or flight response
State of physiological arousal when the body is prepared for action
Define Adrenalin
Hormone released as part of the fight or flight response
Define genotype
The genetic make up of an individual, including things that can be seen.
E.g. XX, XY
Define phenotype
Refers to observable, physical characteristics of an organism
E.g. Male, blonde hair
Nervous system can be divided into 2 major parts:
Central nervous system (CNS)
Peripheral nervous system (PNS)
Describe the CNS
- Made up of the brain and spinal cord
- CNS is concerted to the rest of the body by the PNS
Describe the PNS
- Made up of nerves, carrying messages back and fourth between the CNS and the muscles, organs and senses in the periphery of the body
- The PNS has 2 subdivisions: the somatic nervous system and the autonomic nervous system
Describe the Somatic nervous system
- Responsible for voluntary movement and for sensing external stimuli
Describe the autonomic nervous system
- Regulates functions that are not consciously controlled.
E.g. breathing, heart rate, fight or flight - Made up of sympathetic and parasympathetic nervous systems
What is the sympathetic nervous system
- Prepares the body for physical action
What is the parasympathetic nervous system
Puts the body into a relax state, to conserve resources
What is homeostasis
- A state of equilibrium in the body
- Sympathetic and parasympathetic nervous systems work together to maintain body’s homeostasis
What are dendrites and where are they
These receive the nerve impulse from adjacent neurons
- They’re at the end of the neuron (where the cell body is)
What’s the axon
Where the electrical signals pass along
What’s the myelin sheath
Insulates the axon so that the electrical impulse is not lost to the surroundings
What’s the synaptic terminals
Send signals to an adjacent cell as a chemical message
Describe the synaptic transmission process
1) Electrical impulse enters the Axon Terminal
2) Vesicles therefore release neurotransmitter
3) Neurotransmitter travels across the synaptic cleft
4) Neurotransmitter are taken up by the receptors
5) Transfers the impulse from chemical back to electrical, down to the muscle
Describe the process of the electrical impulse (where it travels through) and how
The receptors of a neuron receive the chemical impulse. Info is then carried around body via the long part of the neuron called the Axon. The Myelin Sheath acts to insulate the Axon. At end of neuron are the Axon Terminals. This is where the impulse is converted into a chemical message and passed across the Synapse to an adjacent cell.
What’s an excitatory neurotransmitter
Increases the chances of an adjacent cell producing an electrical impulse
What’s an inhibitory neurotransmitter
Decreases the chances of an adjacent cell producing an electrical impulse
What’s a reflex action
A reflex is an automatic response to a stimulus that does not involve the brain
Draw a reflex action flow chart
Stimulus—> Pain receptors->Sensory neuron
(Pin In skin). /
Muscle fibres
What’s an afferent neuron
What’s an efferent neuron
- Afferent= A nerve carrying a message towards the CNS
- Efferent= A nerve carrying a message away from the CNS, towards the effector (Muscle)
Name the 6 organs affected by fight or flight response
Digestive system Heart Liver Bladder Eyes Muscles
Explain how the digestive system, heart and liver are affected by the sympathetic nervous system during fight or flight and how it is helpful
- Digestive system= Inhibits motility (slows down digestive system)- therefore more blood supply for something else
- Heart= Heart rate increases, vasoconstriction and vasodilation of arterioles- more oxygenated blood to the working muscles
- Liver= Releases Glucose- Sugar in blood, more energy
Explain how the bladder, eyes and muscles are affected by the sympathetic nervous system during fight or flight and how it is useful
Bladder= Relaxes bladder- Less weight, can run quicker
Eyes= Dilates pupils- Can see clearer
Muscles= More oxygen and energy in the muscles- Work for longer
How does the fight or flight response come about
1) The hypothalamus in the brain detects a threat
2) It sends a message to the adrenal gland (above kidneys)
3) Adrenalin is released
What is Phenylketonuria (known as PKU)
An inherited disorder in which sufferers cannot break down a dietary amino acid called phenylalanine
What’s the result of phenylalanine not being broken down
Builds up in the tissues of the body causing impairments of brain function, seizures and facial deformity
Is a person who suffers from PKU have a normal phenotype
Untreated children exhibit normal phenotypes at birth, but fail to attain early develop,entail milestones, and go on to develop other symptoms
When does PKU become apparent and why
In early childhood as toxic levels of the chemical (phenylalanine) build up in the body over time
How are baby’s tested for PKU
Blood is taken from the heel of a newborn baby and tested for the presence of the disease
Can a baby with PKU grow up with normal development
Yes, a newborn can grow up with normal development by controlling Phenylalanine levels through diet
What’s an intervention, in terms of PKU
Action taken to improve a medical disorder (PKU). Can do this by controlling phenylalanine levels through diet
What is your eye genotype
What is your eye phenotype
What is your sex phenotype
What is your sex genotype
Phenotype for eyes= Blue eyes
Genotype for eyes= bb
Sex phenotype= Male
Sex genotype= XY
