Biological Aspects of Psychology Flashcards
Biological Pathway
Study of the cells and organs of the body, and the physical and chemical changes involved in behaviour and mental processes
Nervous sytem
Cells that make up your brain, spinal cord and other nerve fibres. They tell you what is going on inside and otuside your body and allows you to make appropriate responses.
Function - input , processing and output info
Structure of Neuron
- Dendrites - Receives information from other neurons and sends them to the cell body.
- Cell and nucleus
- Axon - carries signals away from the cell body
- Myelin Sheath - protects the signal with an insulated sheath. Allows for fast transmission.
- Nodes of Ranvier
- Terminal buttons - Signal is released into the synaptic gap through the terminal buttons.
- Cell sends an electric charge through the axon towards the presynaptic terminal.
Electrical/chemical process in neural transmission
- Cell sends electrical charge through the axon towards to presynaptic terminal.
- The electrical charge stimulates the presynaptic terminal to release chemical messages
- Messages cross the synaptic gap and are taken up by the post synaptic terminal. and this produces an electrical charge.
Action potential
- Membrane potential - difference in charge between inside and outside of the cell.
- -70mV - resting potential and polarised.
- Muscles are relaxed, there is a change . (your hand will drop or throw)
Excitatory potentials
Excitatory depolarises the neuron and is more likely to generate an AP
Inhibitory potential
Hyperpolarise the neuron and generates an AP.- Resting membrane potential - difference in charge between inside and outside of the cell.
- 70mV - “resting potential” , “polarised”
Neurotransmitter release and reception
- Axonal conduction: Myelinated axons - nodes of Ranvier and saltatory conduction
- Velocity - depends on size of axon and myelination , human motor neurons.
Nerve Cell communication
- Action potential shoots down the axon, away from the cell body.
- A neurotransmitter is released into the synapse, where the dendrites of neighbouring neurons detect it. See enlarged area.
- If there is a receptor for this neurotransmitter on the dendrites, the neurotransmitter and receptor bind, creating an electrochemical signal.
- If the signal is strong enough it spreads down the dendrites and across the cell body of the next neuron and begins another action potential.
Serotonin - affect on thoughts and behaviour
mood appetite, impulsivity (malfunction = depression)
Norepinephrine - affect on thoughts and behaviour
Mood, sleep, learning (depression)
Dopamine affect on thoughts and behaviour
Movement, reward (Parkinsons, shizophrenia)
GABA - affect on thoughts and behaviours
sleep movement (anxiety, Huntington’s disease, epilepsy)
Acetylcholine affect on thoughts and behaviour
memory, movement (damage after cardiovascular accident.
Message termination: Reuptake
Increases (serotonin) available in the system as action potential happens and neurotransmitters release into the synaptic gap and locks onto the receptors on the post synaptic cell and inhibit or excite a response.
Message termination - enzymatic degradation
monoaminoxidase slows the rate of the neurotransmitter being broken down and it increases the amount of neurotransmitters in the synaptic gap.
Drug and synaptic transmission
- Agonists - bind to post synaptic receptors and active
- Antagonist (receptor blockers) - bind to postsynaptic receptors but do not activate.
Two systems
- Central Nervous system consists of the brain and spinal cord, which are encased in bone for protection and the CNS receives information, processes it, and determines a response.
- Peripheral Nervous System - Extends through out the body and, like an email or instant messaging service and relays information to and from the brain. Somatic - sensory and motor and Autonomic - sympathetic and parasympathetic
Function of the Peripheral NS
- Peripheral: Autonomic Nervous system - controls basic life function - heart beat, respiratory, response to stress.
- Sympathetic - Used in emergency situations, Release adrenaline from adrenal glands, increased heart and breathing rate, reduced blood in the extremeties. fight, flighty, freeze
- Parasympathetic - Conserves and maintains the body’s resources. Regulates blood sugar levels. secretes saliva and removes waste.
Central NS function
The spinal cord relays signals from the senses to the brain and then from the brain to the muscles, directs reflexes.
Forebrain
limbic system, fighting, fleeing, feeding and faunicating. amygdala - detects harm, fear response and hippocampus. Basal ganglia - voluntary motor responses, damage causes movement abnormalities. Hypothalamus - regulates eating sleeping and sexual behaviour.
Midbrain
basic auditory and visual functions, movement and arousal, orients body movement towards visual and auditory stimuli
Hindbrain
pons: respiration, movement, sleep, wake - cerebellum - cognitive functions and sensorimotor, medulla - connects spinal cord and the brain, heartbeat, circulation - reticular formation basic survival mechanisms.
Corpus Callosum
tract of myelinated axons that join the left and right sides of the brain.
Thalamus
two lobed structure that receives input from sensors and relays information from senses to higher structures in the brain.
Four lobes of cerebral cortex
decision making, problem solving, learning and voluntary movement. grey and white matter. - frontal, temporal, parietal and occipital
Functional areas of the cerebral cortex
Motor cortex - movement , visual cortex - sight, auditory cortex- hearing. somatosensory cortex.
Major brain imaging techniques
EEG, PET, MRI, FMRI
differences between brain imagine techniques
EEG - cognitive activity, poor spatial resolution of activity, electrical activity of the brain with electrodes on head
PET - specific changes in neuronal activity, for research and uss low levels of radioactivity
MRI - exposes brain to magnetic field = high resolution image of brain anatomy, no radioactivity
FMRI - detects changes that are ongoing in neural activity. Combined advantages of PET and MRI.
Functions of NS
- Pituitary gland - in the brain: releases several hormones that stimulate and regulate other endocrine glands.
- Hormones released: (adrenocorticotrophic hormone)ACTH. (thygroid stimulating hormone) TSH, ( growth hormone) GH
Brain anatomy
Neuron structure
https://cdn1.byjus.com/wp-content/uploads/2020/02/STRUCTURE-OF-NEURON.png
Glial cells
Help neurons communicate by directing their growth, keeping their chemical environment stable, providing energy, and secreting chemicals to help restore damage.
No glial cells = no functioning neurons
Neurotransmitters
Chemicals are stored in vesicles at the tops of axons. When an action potential, reaches the end of an axon, a neurotransmitter is released into the synapse, where it spreads to reach the next, or postsynaptic cell.
Peripheral NS (somatic),
Sensory neurons bring info to the brain. Motor neurons carry info from the brain to direct motion.
peripheral (autonomic) - sympathetic/parasympathetic
Carries messages back and forth between the CNS and the heart, lungs, and other organs and glands, and the message increases or decreases the activity of the organs and the glands= meet demands.
Reticular formation
In the hindbrain and midbrain this network alters the activity of the rest of the brain. It is involved in arousal and attention. The fibers from the reticular system are disconnected from the rest of the brain
Cerebellum
Involved in planning and execution of movements. It also is involved in things other than physical movmemtn including memory, impulse control, pain, emotion, language and other higher - order cognitive processes. It is important in timing.
Structures of brain labelled
https://encrypted-tbn0.gstatic.com/images?q=tbn:ANd9GcQjfz4TrBIPFbf9E3C92jsfQ_qrIfNDbyYIPg&usqp=CAU
Thalamus
Relays pain signals from the spinal cord, signals from the eyes and most other sense organs, to upper levels in the brain
Hyperthalamus
Involed in regulating hunger, thirst and sex drive
Hippo- and amygdala
Part of the limbic system. The amgydala in the forebrian, is involved in fear and reward learning.
Hippocampus - associated with formation of new memories.
Cerebral Cortex
Outer surfaceof the brain and has cerebral hemispheres - left and right halves of the brain
Parts of the cerebral cortex
Motor Cortex - neurons control voluntary movements in specific parts of the body
association cortex - receive informatin from one + sense or combine sensory and motor info = complex cognitive tasks
Prefrontal cortex - other areas in the front of the brain
