Biopsychology Flashcards
What makes up the nervous system?
CNS - brain and spinal chord, PNS - somatic nervous system (motor neurones), autonomic nervous system (regulates glands, blood, etc) - sympathetic (fight or flight), parasympathetic (rest state)
Cerebrum
4 lobes - behaviours
Cerebellum
Motor skills, muscle coordination
Diencephalon
Made up of thalamus and hypothalamus
Brain stem
Automatic function
Somatic
Connects CNS and senses- 12 cranial nerves - involved in reflex action.
Autonomic
Automatic actions - regulate organs
Sympathetic
Deal with emergencies - fight or flight - increase heart rate/ blood pressure
Parasympathetic
Relaxes body after emergency passed- rest state.
Sensory neurones
Carry nerve impulses from sensory receptors to spinal cord toward brain
Relay neurones
Allow communication between motor and sensory neurones
Motor neurones
Control muscle movements
Structure of a sensory neurone
Receptor cell > myelin sheath > axon > cell body/ nucleus > axon terminal
Structure of a motor neurone
Dendrites > cell body / nucleus > Axon > Myelin sheath > Axon terminal
Structure of a relay neurone
Dendrite > Cell body / nucleus > axon > axon terminal
What is the process of synaptic transmission?
As the message is converted to an electrical impulse and is rapidly fired down the axon as an action potential, it reaches the axon terminal where it makes contact with the synaptic vesicales that burst releasing neurotransmitters. These diffuse across the synapse and make contact with receptors on the dendrites. Once the impulse has been transferred and summation has occurred, it is sent back to be reabsorbed.
Excitatory Neurotransmitters
Cause the excitation of the post synaptic neurone - positive charge.
Inhibitory Neurotransmitters
Calming body and mind - negatively charged.
Summation
Likelihood of impulse firing calculated by adding up excitatory and inhibitory neurotransmitters - more excitatory = fire, more inhibitory = not fire.
Glands
Secrete hormones into the blood stream to regulate the body.
Pituitary
Master gland - regulates endocrine system
Adrenal Glands
Fight or flight - adrenaline
Testes
Testosterone in males.
Ovaries
Oestrogen and progesterone in females
What do the adrenal glands release?
- Outer part (cortex) - cortisol - anti-inflammatory and cardiovascular
- Inner part (medulla) - adrenaline and noradrenaline
How are hormones released?
The hypothalamus sends a signal to the pituitary gland to release a stimulating hormone to the target gland. This will then release its hormone. When too much has been released the hypothalamus will shut down the release of the stimulating hormone from the pituitary, inhibiting the hormone from the target gland.
What can too high/ too low levels of hormones do?
Cause symptoms like high blood pressure, fatigue, weight gain or loss, heart attacks, Cushing’s syndrome (too high cortisol)
What does the pituitary gland release?
Anterior - ACTH (stress hormone), LH, FSH
Posterior - oxytocin (contraction of uterus)
Fight or Flight
Response survival mechanism when the body detects a threat.
Process of Fight or Flight
Amygdala detects a threat from senses and sends a signal to the hypothalamus. This triggers either the acute stressors response, or the chronic stressors response.
Acute Stressors Response
Adrenaline released by the sympathetic nervous system > causes physiological changes > parasympathetic nervous system calms the body after the even has passed.
Chronic Stressors Response
HPA Axis - hypothalamus releases CRH, causing the production of ACTH in the pituitary. This stimulates the adrenal cortex to produce cortisol. Once levels are back to normal, CRH and ACTH production is stopped.
Gray 1988 - fight or flight or run away
First phase of reaction to a threat is not to fight or flee but avoid confrontation. Most animals display ‘freeze’ response, where they ‘stop, look and listen’- able to take in new information to decide on response.
Von Dawans et al 2012 - gender differences in fight or flight
Men ‘fight or flight’ and women ‘tend and befriend’. Found that acute stress often leads to more cooperative/ friendly behaviour in anyone- can explain human connection in times of crisis like 9/11.
Lee and Harley (2012)- gender in fight or flight
Found evidence of genetic basis for gender differences in fight or flight response. The SRY gene found in male Y chromosomes promotes aggression. May cause fight or flight more in males with the release of adrenaline. Lack of gene in females causes release of oestrogen and oxytocin, preventing fight or flight response.
Localisation
Specific functions located in specific areas of the brain.
Motor cortex
Responsible for voluntary motor movements - frontal lobe alone the pre central gyrus.
Somatosensory cortex
Detects sensory information - parietal lobe
Visual Cortex
Visual processing - occipital lobe
Auditory cortex
Audio processing - temporal lobe
Broca’s Area
Left frontal lobe - language production. Research into ‘Tan’ (could only say that syllable) found that damage to this area resulted in an ability to speak.
Wernicke’s Area
Posterior left temporal lobe - language comphrension
Lashley 1930 - Equipotentiality
Basic functions are localised but more complex ones are not. Intact areas can take over function of damaged ones.
Joseph Dejerine (1892)- localisation and reading
Loss of ability to read resulted in damage to connection between Wernicke’s area and visual cortex- complex processes built up gradually.
Bavelier et al (1997)- activation individual differences
Large variability in patterns of activation across different individuals. Activity on right temporal lobe as well as left frontal, temporal and occipital lobes.
Harasty et al (1997)- gender localisation
Women have larger Broca’s and Wernicke’s areas than men- greater use of language.
Dronkers et al (2007)- re-examination
Re-examined brains of Tan and another Broca patient using MRI technology- other defective areas may have contributed to speech problems. Lesions to Broca’s area usually don’t cause severe speech issues.
Localisation evaluation
- Communication may be more important
- Aphasia studies
- Individual differences - pattern of activation
- May not be due to damage in one area.