1. The nervous system
AO1:
- Nervous system: communication using electrical signals, consists of CNS and PNS.
- Central nervous system (CNS): made up of brain and spinal cord, origin of
commands/demands.
- Peripheral nervous system (PNS): sends info to the CNS from the environment
(sensory neurons), and from CNS to environment (motor neurons).
- Somatic nervous system (SNS) :transmits information from the receptor cells in
sensory muscles to the CNS, governs muscle movement.
- Autonomic nervous system (ANS): transmits info to and from the internal organs, it is
automatic. E.G. breathing, heart rate, digestion etc. Two parts; sympathetic
(increases) and parasympathetic (decreases) NS.
2. The endocrine system
AO1:
- Endocrine system: major information system, instructs glands to secrete hormones
into the bloodstream. Carried towards major organs - communicates via chemicals.
- Glands: organ in the body that secretes hormones.
- Hormone: biochemical substance that circulates in blood and affects target organs.
Produced in large quantities, they disappear quickly (powerful).
- Thyroxine: from thyroid gland, main aim: increases heart rate -> increases metabolic/
growth rate.
- Adrenal glands: secretes adrenaline, causes arousal response to fight or flight,
increases activity with branches of NS.
- Pituitary gland: ‘master gland’, located in the brain, controls release of hormones
from other glands.
3. Fight or flight response
AO1:
- Fight or flight response: the way an animal responds to stress. Body becomes
physiologically stressed ready to fight an aggressor or to flee.
- Adrenaline: hormone from adrenal glands, part of the body’s immediate stress
response system. Strong effect on cardiovascular system - heart rate, contracting
blood vessels, dilating air passages.
- Immediate and automatic: once threat is detected, the response is automatic-
physiologically aroused sympathetic.
- Parasympathetic: once threat has passed, the body will return to normal state.
Reduces activities of the body put into place by sympathetic actions. Rest and digest
response.
- PROCESS:
1. Body becomes aware of a stressor.
2. Receptors in the PNS, info sent to hypothalamus, coordinates hormone response.
3. Adrenaline released, sent to target effectors.
4. Actions such as rectum contracting, saliva production, greater breathing rate.
Purpose is to overcome stress and improve chances of survival.
5. As threat goes, the body returns to a parasympathetic state; rest and digest.
4. Neurons and synaptic transmission
Neurons, AO1:
, - Neurons: building blocks of the nervous system, cells that process messages through
chemical signals.
- Sensory neurons: carry messages from PNS to CNS. Long dendrites, short axons.
- Relay neurons: connect sensory neurons to motor or other relay neurons.
- Motor neurons: connect CNS to effectors such as muscles or glands. Short
dendrites, long axons.
- Structure of a neuron: difference in size, same basic structure:
- Nucleus: carries genetic material.
- Dendrites: carry nerve impulses away from neighboring neurons.
- Axon: carries impulses away from the cell body. Covered in myelin sheath to protect
and speed transmission. Separated into nodes of Ranvier, speeds up by making an impulse
‘jump’.
- Terminal buttons that communicate with the next neuron through the synapse.
- Location of neurons: Cell bodies in the CNS of motor neurons, long axons in the PNS.
Relay neurons make up 97% all, located in the brain and visual system. Sensory neurons
located outside of CNS or in PNS in clusters (ganglia).
Cell resting state - inside of the cell is negatively charged. Neurons activated by a stimulus
inside of a cell become positively charged for a split second, causing action potential.
Creates an impulse that travels down the axon to the end of the neuron.
Synaptic transmission, AO1:
- Synaptic transmission: process where neighbouring neurons communicate through
synapse that separates them.
- Neurotransmitters: brain chemicals released by synaptic vesicles that send signals
across the synapses. Can be broadly divided.
- Excitation: neurotransmitters (e.g. adrenaline) increase positive charge of
postsynaptic neurons, increase likelihood of electrical impulse. If the net effect is
excitatory, the neuron will be more likely to fire.
- Inhibition: neurotransmitters such as serotonin, increase negative charge of
postsynaptic neurons. Decreases likelihood of passing on electrical impulses of
postsynaptic neurons.If the net effect on the postsynaptic neuron is inhibitory, the
neuron will be less likely to fire.
5. Localisation of function
AO1:
- Localisation of function: theory that different areas of the brain are responsible for
different functions.
- Motor area: region of the frontal lobe involved in regulating movement.
- Somatosensory area: area of the parietal lobe that processes sensory information
e.g. touch.
- Visual area: occipital lobe that receives and processes visual processes.
- Auditory area: located in the temporal lobe, concerned with analysis of speech-based
information.
- Broca’s Area: area of the frontal lobe in the left hemisphere (for most) that is
responsible for speech production. Patient Tan, damage to this area caused a lack of
speech - Tan was the only word he could say. (Broca’s Aphasia)
AO1:
- Nervous system: communication using electrical signals, consists of CNS and PNS.
- Central nervous system (CNS): made up of brain and spinal cord, origin of
commands/demands.
- Peripheral nervous system (PNS): sends info to the CNS from the environment
(sensory neurons), and from CNS to environment (motor neurons).
- Somatic nervous system (SNS) :transmits information from the receptor cells in
sensory muscles to the CNS, governs muscle movement.
- Autonomic nervous system (ANS): transmits info to and from the internal organs, it is
automatic. E.G. breathing, heart rate, digestion etc. Two parts; sympathetic
(increases) and parasympathetic (decreases) NS.
2. The endocrine system
AO1:
- Endocrine system: major information system, instructs glands to secrete hormones
into the bloodstream. Carried towards major organs - communicates via chemicals.
- Glands: organ in the body that secretes hormones.
- Hormone: biochemical substance that circulates in blood and affects target organs.
Produced in large quantities, they disappear quickly (powerful).
- Thyroxine: from thyroid gland, main aim: increases heart rate -> increases metabolic/
growth rate.
- Adrenal glands: secretes adrenaline, causes arousal response to fight or flight,
increases activity with branches of NS.
- Pituitary gland: ‘master gland’, located in the brain, controls release of hormones
from other glands.
3. Fight or flight response
AO1:
- Fight or flight response: the way an animal responds to stress. Body becomes
physiologically stressed ready to fight an aggressor or to flee.
- Adrenaline: hormone from adrenal glands, part of the body’s immediate stress
response system. Strong effect on cardiovascular system - heart rate, contracting
blood vessels, dilating air passages.
- Immediate and automatic: once threat is detected, the response is automatic-
physiologically aroused sympathetic.
- Parasympathetic: once threat has passed, the body will return to normal state.
Reduces activities of the body put into place by sympathetic actions. Rest and digest
response.
- PROCESS:
1. Body becomes aware of a stressor.
2. Receptors in the PNS, info sent to hypothalamus, coordinates hormone response.
3. Adrenaline released, sent to target effectors.
4. Actions such as rectum contracting, saliva production, greater breathing rate.
Purpose is to overcome stress and improve chances of survival.
5. As threat goes, the body returns to a parasympathetic state; rest and digest.
4. Neurons and synaptic transmission
Neurons, AO1:
, - Neurons: building blocks of the nervous system, cells that process messages through
chemical signals.
- Sensory neurons: carry messages from PNS to CNS. Long dendrites, short axons.
- Relay neurons: connect sensory neurons to motor or other relay neurons.
- Motor neurons: connect CNS to effectors such as muscles or glands. Short
dendrites, long axons.
- Structure of a neuron: difference in size, same basic structure:
- Nucleus: carries genetic material.
- Dendrites: carry nerve impulses away from neighboring neurons.
- Axon: carries impulses away from the cell body. Covered in myelin sheath to protect
and speed transmission. Separated into nodes of Ranvier, speeds up by making an impulse
‘jump’.
- Terminal buttons that communicate with the next neuron through the synapse.
- Location of neurons: Cell bodies in the CNS of motor neurons, long axons in the PNS.
Relay neurons make up 97% all, located in the brain and visual system. Sensory neurons
located outside of CNS or in PNS in clusters (ganglia).
Cell resting state - inside of the cell is negatively charged. Neurons activated by a stimulus
inside of a cell become positively charged for a split second, causing action potential.
Creates an impulse that travels down the axon to the end of the neuron.
Synaptic transmission, AO1:
- Synaptic transmission: process where neighbouring neurons communicate through
synapse that separates them.
- Neurotransmitters: brain chemicals released by synaptic vesicles that send signals
across the synapses. Can be broadly divided.
- Excitation: neurotransmitters (e.g. adrenaline) increase positive charge of
postsynaptic neurons, increase likelihood of electrical impulse. If the net effect is
excitatory, the neuron will be more likely to fire.
- Inhibition: neurotransmitters such as serotonin, increase negative charge of
postsynaptic neurons. Decreases likelihood of passing on electrical impulses of
postsynaptic neurons.If the net effect on the postsynaptic neuron is inhibitory, the
neuron will be less likely to fire.
5. Localisation of function
AO1:
- Localisation of function: theory that different areas of the brain are responsible for
different functions.
- Motor area: region of the frontal lobe involved in regulating movement.
- Somatosensory area: area of the parietal lobe that processes sensory information
e.g. touch.
- Visual area: occipital lobe that receives and processes visual processes.
- Auditory area: located in the temporal lobe, concerned with analysis of speech-based
information.
- Broca’s Area: area of the frontal lobe in the left hemisphere (for most) that is
responsible for speech production. Patient Tan, damage to this area caused a lack of
speech - Tan was the only word he could say. (Broca’s Aphasia)
