Biopsychology Flashcards
What’s the nervous system?
A network of cells in the human body
The body’s internal communication system
What’s the function of the nervous system?
To collect, process and respond to information from the environment.
To control organs and cells in the body.
The Nervous System: Two Main Parts
The central and peripheral nervous system.
The Nervous System: What’s the Central Nervous System made up of?
Made up of the brain and spinal chord.
Brain’s responsible for higher mental functioning.
Spinal chord’s responsible for reflex actions and transmitting info to and from the brain.
The Nervous System: What’s the Peripheral Nervous System made up of?
Sub-divided into the autonomic and somatic nervous system.
The Nervous System: What’s the Autonomic Nervous System responsible for?
Responsible for involuntary functions e.g. breathing and digestion.
ANS can be further sub-divided into sympathetic (responsible for fight or flight response) and parasympathetic (conserves and restores body energy when relaxed) branches.
The Nervous System: What’s the Somatic Nervous System responsible for?
Responsible for voluntary movements e.g. walking.
Transmits info from the brain to the skeletal muscles/ effectors.
Structure and Function of Neurons: What are Neurons?
Neurons are cells that make up the nervous system.
They communicate with each other using a mixture of electrical and chemical signals.
1) Structure and Function of Neurons: Dendrites
Located at the post-synaptic membrane.
Where the neurotransmitter receptors are found.
Once receptor and neurotransmitter bind, causes a new electrical impulse to occur.
2) Structure and Function of Neurons: Cell Body
Includes the nucleus which contains the genetic material of the cell.
3) Structure and Function of Neurons: Axon
Sends a nerve impulse (action potential) through the neuron to transmit a message to the next neuron.
4) Structure and Function of Neurons: Myelin Sheath
Protect the axon and helps to speed up transmission of the message.
5) Structure and Function of Neurons: Nodes of Ranvier (the gap)
Speeds up the transmission of the impulse by forcing it to ‘jump’ across the gaps along the axon.
6) Structure and Function of Neurons: Terminal Button (pre-synaptic membrane)
The end of the neuron.
Sends information through to the next neuron, through the release of neurotransmitters.
Sensory Neuron: Location
The PNS in clusters known as ganglia.
Sensory Neuron: Function
Send info from the senses (PNS) towards the brain (CNS).
Receptors found in eyes, ears, tongue, skin.
Sensory Neuron: Structure
Have long dendrites and short axons.
Relay Neuron: Location
In the brain and the visual system.
Relay Neuron: Function
Found in the CNS (brain/ visual system/ spinal chord).
Carry nerve impulses between neurons allowing sensory and motor neurons to communicate.
Involved in analysing sensations from these neurons and deciding how to respond.
Relay Neuron: Structure
Have short dendrites and short axons, and no myelin sheath.
Motor Neuron: Location
Cell bodies are found in the CNS
Long axons form part of the PNS.
Motor Neuron: Function
Send info via long axons from the brain/ spinal chord (CNS) through to effectors such as muscles/ glands.
Motor Neuron: Structure
Have short dendrites and long axons.
Process of Synaptic Transmission: What are neurotransmitters?
Chemical messengers within the brain.
Their role is to transmit info from one neuron to another so a person performs an action e.g. movement or has an emotional response.
The Process of Synaptic Transmission
1) Begins at pre-synaptic neuron, action potentials (electrical nerve impulses) sent down axon until they reach presynaptic terminal.
2) Causes neurotransmitters stored in vesicles (only located in presynaptic neuron) to be released into synaptic cleft (gap between each neuron).
3) Neurotransmitters diffuse across synapse (high to low concentration) and bind with specific receptor sites only present in post-synaptic neuron.
4) Enough neurotransmitters attached to receptor sites on post-synaptic neuron, two possible outcomes:
- Next neuron’s ready to fire an impulse, depending on whether neurotransmitter has excitatory or inhibitory effect.
- Neurotransmitters are recycled to be stored back in the vesicles in pre-synaptic neuron in a process called reuptake.
Neurotransmitters Effect on the Next Neuron: Excitatory Neurotransmitter (Adrenaline)
When excitatory transmitter bind to post-synaptic receptors the post-synaptic cell (next neuron) becomes positively charged.
Makes it more likely that the post-synaptic cell will fire so an impulse will travel down the axon.
Increases brain activity in CNS.
Neurotransmitters Effect on the Next Neuron: Inhibitory Neurotransmitter (Serotonin)
Inhibitory neurotransmitter binds to post-synaptic receptors the post-synaptic cell (next neuron) becomes negatively charged.
Prevents/ reduces likelihood that post-synaptic cell will fire.
Decreases brain activity in CNS.
Neurotransmitters Effect on the Next Neuron: Summation
Occurs when excitatory & inhibitory influences are added together.
If overall effect’s mainly inhibitory/ negatively charged, reduces likelihood the neuron will fire an impulse down post-synaptic neuron.
If overall effect’s mainly excitatory/ positively charged, neuron will fire impulse down post-synaptic neuron.
The function of the endocrine system
Endocrine system provides chemical system of communication within blood stream to regulate activity of cells/ organs in the body.
It’s slower than the nervous system but its effects are more widespread and powerful.
Chemical messengers are hormones which are released by glands within endocrine system to regulate bodily function.
The role of glands in the endocrine system: What is a gland?
An organ that releases hormones that control/ regulate bodily functions.
Many different glands in the body.
The role of glands in the endocrine system: Pineal Gland
Secretes hormone melatonin, involved in regulating the sleep-wake cycle by making a person feel tired and ready to sleep.
The role of glands in the endocrine system: Pituitary Gland
Master gland.
Controls functions of other glands.
Secretes many different hormones that control function of other glands.
The role of glands in the endocrine system: Adrenal Gland
Releases adrenaline which causes physiological changes involved in the fight or flight response e.g. increased blood flow to transport oxygen to brain for rapid response planning.
The role of glands in the endocrine system: Ovaries
Anterior pituitary gland releases LH and FSH
Encourages ovaries to release oestrogen and progesterone which regulate female menstrual cycle and prepares body for reproduction.
The role of glands in the endocrine system: Testes
Anterior pituitary gland releases LH and FSH.
Encourages testicles to release testosterone which is involved in creating male characteristics and the production of sperm.
The Fight or Flight Response
The ANS and the endocrine system plays major role in stress response in producing fight or flight response.
When stressor’s identified by brain it activates sympathetic branch of ANS.
1) Stressor’s identified by hypothalamus and activates pituitary gland which triggers activity in sympathetic branch of ANS.
2) Adrenaline’s released by adrenal medulla into bloodstream.
3) ‘Fight or flight’ response is produced, preparing body for sudden physical action, produces physiological reactions e.g. increased heart rate - this is an immediate and automatic response.
4) Parasympathetic branch returns the body back to normal once stressor’s been removed (homeostasis e.g. heart rate decreased).
Role of Adrenaline in Fight or Flight Response
Adrenaline’s the hormone released from the adrenal medulla.
Travels through bloodstream and activates heart and circulatory system, increases heart rate and blood pressure.
Changes are important in fight or flight response.
Direct effect of Adrenaline in Fight or Flight Response
Increased heart rate increasing blood flow and blood pressure.
Increases blood flow to brain and skeletal muscles.
Indirect effect of Adrenaline in Fight or Flight Response
Prepares body for action e.g. fight or flight.
Increases blood supply yo skeletal muscles for physical action, stops digestion and saliva production.
Increased oxygen to brain for rapid response planning.
What happens once stressor’s removed: Parasympathetic Branch
Once stressor’s passed, parasympathetic Branch of ANS takes over.
Main function’s to activate ‘rest and digest response’ and return body to homeostasis after fight or flight response.
AO3: Fight or Flight Response: Stress Response in Females (Tend and Befriend)
P: Issue is that it doesn’t explain stress response in females.
E: Research’s found women are more likely to protect offspring (tend) and form alliances with other women (befriend) than to fight or run away.
E: Suggests there’s gender bias as fight or flight response assumes men and women respond to threatening situation in same way prior to research.
L: Limits explanation for fight or flight.
AO3: Fight or Flight Response: Limited to Two Responses
P: Issue, human behaviour’s not limited to two responses.
E: Psychologists argue first response to danger’s to avoid confrontation altogether through ‘freeze’ response.
E: During ‘freeze’ response humans consider best course of action for threat they’re faced with.
L: Suggests fight or flight response doesn’t consider other factors such as thought process.
Localisation of Function in the Brain and Hemispheric Lateralisation: Introduction
Localisation of Function: Specific areas of the brain specialised for certain functions (jobs) e.g. motor cortex is responsible for voluntary movements- only this area of the brain’s responsible for this job.
Hemispheric Lateralisation: Brain’s split into two symmetrical halves called left and right hemisphere. Idea that two different hemispheres are responsible for different mental processes e.g. left responsible for language, right responsible for creativity.
Holistic theory: Before investigations into localisation and lateralisation, scientists believed all parts of brain worked together when processing information.
Localisation of Function in the Brain and Hemispheric Lateralisation: Broca’s Area
Left hemisphere.
Involved in production of spoken and written language.
Damage to area can cause ‘Broca’s aphasia, person may show slow speech which requires a great deal of effort, speech lacks fluency, or complete loss of speech)
