Dr Thomas Flashcards
1
Q
What is biological psychology?
A
The application of the principles of biology to the study of physiological, genetic, and developmental mechanisms of behaviour
2
Q
Why is biological psychology important?
A
Mental Health:
- Holistic
- Emergent properties
Diminished Responsibility:
- Section 2 of the Homicide act 1967
- Impairments to understanding, judgement, and self-control
Social policy:
- Blank slate perspectives on behaviour can do more harm than good
3
Q
What is a gene?
A
- Smallest unit of inheritance
- Composed of deoxyribonucleic acid (DNA)
- Size: hundreds to millions of bases
- Stored in the cell nucleus, in chromosomes
- Different versions of a gene are called an allele
4
Q
What is DNA?
A
- A double helix
- Sugar phosphate backbone
- Between backbones are bases (adenine, thymine, cytosine, guanine
- Organised into pairs
- Usually grouped in three (codon)
- Codons relate to specific amino acids, joined into chain called peptides
- Peptide chains become proteins
5
Q
Chromosomes
A
- Tightly wound bundles of DNA
- Number/length of chromosomes vary by species
- Each formed from 2 (usually identical) chromatids
- Each human cell has 23 pairs of chromosomes
- Total is 46 chromosomes
6
Q
What is an autosome?
A
Chromosomes 1 through 22 in the human body
7
Q
What is an allosome
A
Sex chromosome in humans
8
Q
What are DNA abnormalities and mutations and the diseases caused by them?
A
Produce a gross imbalance and multiple defects
Partial Deletions:
Chromosome is missing
- Jacobsen, Turner syndrome
Duplications:
Section of DNA is duplicated
- Cat eye, Down syndrome
Translocations:
- Down syndrome
Inversions, insertions:
- Haemophilia A
Instability/breakage:
Chromosomes are unraviling
- Fragile X syndrome
9
Q
What is Jacobsen syndrome?
A
- Loss of material from chromosome 11
- Deletion at the end of the q arm
- Genes in this region are critical for development of several body parts
Symptoms:
- Heart defects
- Intellectual disability
- Low platelets
- Dysplasia
Appearance:
- Wide-set eyes
- Skin folds near eye
- Short upturned nose
- Receding chin
- Low set ears
- Hammer toes
10
Q
What is Klinefelter syndrome?
A
- An extra X chromosome in males (aka XXY)
Symptoms include:
- Tall stature
- Small testicles (hypogonadism)
- Lack of facial, pubic and underarm hair
- Poor muscle development
- Breast tissue development
- Deficits in executive and language functions
11
Q
What are single nucleotide polymorphisms (SNPs)?
A
- Snips
- AT CG pairs swap
Associated with:
- ADHD
- Lactose intolerance
- Eye colour
12
Q
Example of SNPs: Niwa et al (2010)
A
- SNPs in DISC1 associated with schizophrenia in humans
- Causes symptoms when suppressed in mice during last week of foetal development
13
Q
What is a genetic disorder?
A
- Single gene disorders: Huntington’s disease
- Chromosomal disorder: Down syndrome
- Very little input from environment
- No treatment
14
Q
What is genetic vulnerability
A
- Many genes x environment = disorder
- Most traits are polygenic
15
Q
Examples of variation in environmental influence
A
Some traits develop rigidly (doesn’t have to be subjected to things in the environment to develop):
- Hand
- Eye
- Fixed action patterns (FAP)
- Imprinting (Lorenz)
Others highly flexible (environmental influence):
- Intelligence in young children
- Religiosity
- Height
- Body fat %
16
Q
What is the central nervous system?
A
- Formed from your brain and spinal cord
- Controls somatic and autonomic nervous systems
- Somatic nervous system is in charge in anything that involves you with the surrounding environment e.g. feeling something
- Somatic nervous system also involves involuntary movement
- Autonomic nervous system controls the internal world e.g. heart beating
17
Q
What is the peripheral nervous system?
A
- Anything outside of the CNS that is responsible for senses and motor control
18
Q
CNS: The brain
A
- Part of the CNS
- 2 hemispheres –> connected by the corpus callosum
- Four lobes: occipital, parietal, temporal & frontal
- The more complex a mammal, the more folds in the brain
19
Q
What are the folds in the brain called?
A
- Shallow canyon: Sulcus
- Deep canyon: Fissure
- Bits that pop out: Gyrus
20
Q
CNS: Spinal cord
A
- Spinal nerves from the peripheral nervous system connect the spinal cord to skin, joints and muscles
- Allows the voluntary and involuntary motions of muscles and perception of senses
21
Q
Examples of spinal cord injury
A
C2 injury (cervical) - Tetraplegia --> neck down C6 injury (cervical) - Tetraplegia --> chest down T6 injury (Thoracic) - Paraplegia -->stomach down L1 injury (Lumbar) - Paraplegia --> Hips down
22
Q
Peripheral nervous system: Somatic
A
- Somatic nervous system is responsible for muscle control of body movements
23
Q
Peripheral nervous system: Autonomic
A
- Autonomic nervous system controls bodily functions not consciously directed
- Parasympathetic nerves: “Rest and digest”
- Sympathetic nerves: “Fight or flight”
24
Q
What is the endocrine system?
A
- Means of communication
- Secretes hormones
- Unlike the nervous system, relatively slow, longer-lasting messages
- Coordinates with the nervous system
25
Etymology of endocrine system
```
Endo = within
Crine = secrete
```
26
Types of hormones: Water-soluble hormones
- Hydrophilic
- Dissolve in water
- Formed from amino acids
- Can't pass through cell membranes
- Affect cells by binding to receptors on the surface of the target cell
27
Types of hormones: Fat-soluble
- Dissolve in fats rather than in water
- Are usually formed from cholesterol
- Cell membranes are made (in part) with cholesterol, so the hormones can pass through them
- Affect cells by binding to receptors inside the target cell
28
What is the pituitary gland?
- The 'master gland'
- Its hormones regulate the functions of other endocrine glands
- Has 2 parts each with a separate function
29
What is the hypothalamus?
- Controls the release or inhibition of pituitary hormone production
- Secretes releasing and inhibiting hormones
- Links the nervous and endocrine systems
- 2 connections with the pituitary gland
- Anterior lobe --> via a special portal blood system
- Posterior lobe --> directly via neurons
30
Cortisol regulation
1. Neural signal reaches the hypothalamus
2. Hypothalamus releases corticotropin-releasing hormone
3. CRF reaches thee pituitary gland
4. Pituitary gland releases adrenocorticotropic hormone
5. ACTH reaches adrenal medulla
6. Cortisol produced
31
What is Cushing's disease
- Pituitary gland overproduces ACTH --> adrenal glands overproduce cortisol
- Due to tumours or growths in the pituitary glands
Symptoms:
- Weight gain, moon face, extra fat around neck, red face
- Red stretch marks
- High blood pressure and impaired immunological function
- Poor working memory and concentration
32
What is the thyroid?
- Regulates metabolism via 2 hormones: Thyroxine (T4) and triiodothyronine (T3)
- Controlled by the pituitary gland --> produces TSH = thyroid-stimulating hormone
33
Graces's Disease
- Autoimmune disease
- Immune system attacks thyroid gland
- Leads to hyperthyroidism (too much T3 and T4)
- Affects approx. 1 in 200 people
Symptoms:
- Heart failure, stroke
- Osteoporosis, thinning of skin, brittle hair
- Inflammation and build up of tissue behind eyes, can put pressure of optic nerve
34
Anatomy of a neuron
Soma - cell body
Axon - sends signals to next cell
Dendrites - receive signals from the axons of other cells
35
What is the soma (neurons)
- Cell body of neuron
- Metabolic centre
- DNA stored here
- Information processed here
36
What are dendrites (neurons)
- Branch-like fibres, extend out from a neuron and receive information from other neurons
- Thousands of branches
37
What is the axon (neurons)
- Tail-like part of a neuron that serves as a transmitter
- Action potentials travel down the axon to other neurons
- Terminal buttons --> release neurotransmitters
38
What are the different types of neurons?
Sensory neurons - bring information to the CNS
Interneurons - associate sensory and motor activity in the CNS
Motor neurons - send signals from the brain and spinal cord to muscles
39
What are glial cells?
Type of neuron that is a supporting cell in the nervous system
40
What is myelination?
- Mammalian axons are myelinated by Schwann cells
- Schwann cells are a type of glial cell
- Myelination is a lipid-rich tissue (fat)
- Nerve fibres transmit electricity and, like wire, benefit from myelination and its insulation
41
What does damage and degeneration of the myelin sheath cause?
Multiple sclerosis
Symptoms:
- Changes in sensation
- Visual problems
- Muscle weakness
- Depression
- Difficulties with coordination and speech
- Severe fatigue
- Pain
42
What is within neural transmission
Action potential goes from dendrite --> soma --> axon --> terminal buttons
43
What is the synapse?
- Tiny gap between the terminal buttons of one neuron and the dendrite of the next
- Chemicals flow into the synapse from the terminal buttons
- Not constantly
44
What is the resting potential?
- Electrical charge is different inside and outside of resting neurons
- Charge created by number of electrically charged particles
- Some outside (sodium and chloride)
- Some inside (potassium and proteins)
- Resting charge is maintained by a pump in the cell wall
- Pumps more sodium out than potassium in
45
How does potential change in a neuron?
- Cell membrane is selectively permeable to different particles via different channels
- Some open based on charge within neuron
- Others open via a neurotransmitter, other physical movement of the neuron
46
How do action potentials work?
- Change in neuron's charge that cascades down a neuron's axon
- Cell loses its negative charge = depolarisation
- Cell becomes more negatively charged = hyperpolarization
- Depolarisation of 55mv triggers an action potential
- Causes a chain reaction involving voltage gates
- A positive charge cascades down the axon
47
What are neurotransmitters
- When action potential reaches the terminal button, it causes the release of vesicles of neurotransmitters
- These activate receptors in the postsynaptic membrane
- May bee excitatory or inhibitory (depending on the receptor)
48
Types of neurotransmitters: Acetylcholine
- Triggering muscle contraction
| - Important in memory
49
Types of neurotransmitters: Dopamine
- Smooth/controlled movements
- Attention
- Memory
- Pleasure
50
Types of neurotransmitters: Serotonin
- Regulation of sleep, dreaming and mood
- Arousal
- Depression
Anxiety
51
Types of neurotransmitters: Noradrenaline
- Alertness
| - State of arousal
52
Types of neurotransmitters: Gamma-amino-butyric acid (GABA)
- Inhibitory effect
- anxiety
- Muscle relaxation
53
What is the hindbrain?
- The life centre
- Controls heart rate, respiration, blood pressure and digestion
- Also, coordination of motor movement, posture and sleep patterns
Substructures:
- Medulla
- Pons
- Reticular formation
- Cerebellum
54
What is the cerebellum?
- Cerebellar cortex
- The 'silent area'
- Serves higher cognitive functions
- Processes and integrates sensory information in the context of action
- Voluntary, coordinated, smooth movement
- Allows modification of behaviour with experience
55
What is the midbrain?
- The relay station
- Coordinates sensory information
- Important for visual (and auditory) reflexes like tracking
Substructures:
- Tectum
- Superior colliculus
- Inferior colliculus
- Tegmentum
- Substantia nigra
56
What is the forebrain?
- Higher-level cognitive processes
Substructures:
- Cerebral cortex
- Diencephalon (thalamus and hypothalamus)
- Limbic system (including amygdala, hippocampus)
57
What is the cerebral cortex?
Frontal:
- Planning
- Decision making
- Personality
Parietal:
- Processing sensations of touch
- Temperature
- Pain
Temporal:
- Auditory processing
- Speech
- Language comprehension
Occipital:
- Vision
58
What is the diencephalon?
Thalamus:
- Processing
- Relay centre
- All sensory modalities (except olfaction)
- Arousal, awareness, motor function, Memory involvement
Hypothalamus:
- Control of ANS
- Hormone release
- Homeostasis
59
What is the limbic system?
- Border between cerebral cortex and brainstem
- Memory, learning, motivation and emotion
- Link between sub-cortical structures and the cerebral cortex
- Influences the endocrine system and ANS
Substructures:
- Amygdala
- Cingulate gyrus/cortex
- Parahippocampal gyrus
- Olfactory tract
60
What is the basal ganglia?
- Motor control and action selection (intentional movement)
- Also involved in learning and executive function and emotional processing
- Huntington's/Parkinson's involve irregular output from basal ganglia
61
What are the organisational effects of hormones?
- Permanent effects on structure and function of body and NS
- Have a critical period of development e.g. foetal development
62
What are the activational effects of hormones?
- Immediate effects that 'come and go'
- may cause some structural change
- Hippocampus can shrink in the absence of some H
63
Organisational effects: sex hormones (study)
- 102 neonates (babies)
- Average 37 hours old
- Presented (70s at 20cm) with face or mobile
- Blind judges coded looking time for all the neonates
- 43% boys v 17% girls showed clear mobile preference
- 36% girls v 25% boys had a clear face preference
- Rest were of equal preference
- However, most sexual differentiation is limited until puberty
64
What is the impact on brain development during the organisational effects of sex hormones?
- Preoptic area of hypothalamus is larger in men
- Women's brain share more functions bilaterally than men's
- Men's brain are slightly larger overall
- Women's have more grey matter
65
How sex hormones are regulated in women
- Gonadotropin-releasing hormone varies over 28 days
- As does pituitary sensitivity to gonadotropin-releasing
- Ovary sensitivity to luteinising hormone and follicle stimulating hormone
- LH and FSH crucial to ovulation
66
What are androgens?
- 'Male' sex hormones
- Most commonly Testosterone
- In both sexes, but 20x more in men
- Androgens can be increased or decreased following social cues
67
What are androgens associated with?
- Regulating sexual behaviour
- Developing secondary sexual characteristics
- Muscle hypertrophy
- Spermatogenesis
- Suppressed immune system
- Decreased fat stores
- Increased risk of cancer
- Aggression
- Reduced parental behaviour
68
Testosterone behaviour in rats
Wallen (2001)
- Phases of sexual behaviour in rats (sniffing and mounting) depend on testosterone
- Castrated males fail to show these behaviours (varies with how experienced the rat is before castration)
- Behaviours can be reinstated using artificial T implants
- Anti-androgens also have a similar effect
69
Testosterone behaviour in humans: natural experiments
Wang et al. (2000)
- Used hypogonadal men: reduced sexual functioning, poor mood, lower muscle strength
- Used a transdermal T patch for 180 days to normalise their T levels
- Increase in sexual performance, motivation and desire at 30 days
- Increase in erections and maintenance of those erections at 30 days
- increase in positive moods and decrease in negative mood at 30 days
- Increase in leg press usage and increase in lean body mass at 90 days
70
Testosterone behaviour in humans: other natural experiments
Midgley et al. (2001)
- 60% of those who take steroids report an increase in irritability and temper
- Also more likely to work as doormen
- Anticipation of sexual contact can lead to an increase in testosterone
71
Testosterone behaviour in humans: Lab controlled experiments
Nave et al. (2017)
- Apply T gel to men
| - Can cause men to make rash decisions in reflective tasks such as riddles
72
What are oestrogens?
- 'Female' sex hormones most commonly oestradiol (E)
- In both sexes but up to 8x more in women
- O levels change across the menstrual cycle and work in conjunction with progesterone
73
What is oestrogen associated with?
- Sexual behaviour
- Secondary sex characteristics
- Skin elasticity and firmness
- Sensitivity of brain to oxytocin
- Regulates ovulation
- Bone density and strength
- Mood and wellbeing
- Helps regulate pregnancy
- Too high levels can cause endometriosis
74
Oestradiol and behaviour in rats
Takahashi (1990)
- Ovariectomised rats are not sexually receptive
- This can be reinstated by administering large doses of O
- More effective to do a small amount of O followed by P
- O has a 'priming' effect for P
75
Oestradiol and behaviour in humans: Natural experiments in women with menopause
Nathorst-Böös et al. (1993)
- Menopause = lack of eggs = ovaries shrink
- There is also a decrease in hormones
- Used an O patch
- At 90 days there was an increase in vaginal lubrication, sexual enjoyment, sexual fantasies and sexual frequency
- There was a decrease in pain during intercourse
76
Oestradiol and behaviour in humans: Other natural experiments in women with menopause
Polo-Kantola et al. (1998)
- Randomised, double blind, cross-over study
- Replacement therapy for ) improved sleep complaints at 90 days
- Increased sleep quality, falling asleep and mood
- Decreased restlessness, awakenings and daytime tiredness
