Dr Thomas Flashcards
What is biological psychology?
The application of the principles of biology to the study of physiological, genetic, and developmental mechanisms of behaviour
Why is biological psychology important?
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
What is a gene?
- 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
What is DNA?
- 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
Chromosomes
- 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
What is an autosome?
Chromosomes 1 through 22 in the human body
What is an allosome
Sex chromosome in humans
What are DNA abnormalities and mutations and the diseases caused by them?
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
What is Jacobsen syndrome?
- 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
What is Klinefelter syndrome?
- 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
What are single nucleotide polymorphisms (SNPs)?
- Snips
- AT CG pairs swap
Associated with:
- ADHD
- Lactose intolerance
- Eye colour
Example of SNPs: Niwa et al (2010)
- SNPs in DISC1 associated with schizophrenia in humans
- Causes symptoms when suppressed in mice during last week of foetal development
What is a genetic disorder?
- Single gene disorders: Huntington’s disease
- Chromosomal disorder: Down syndrome
- Very little input from environment
- No treatment
What is genetic vulnerability
- Many genes x environment = disorder
- Most traits are polygenic
Examples of variation in environmental influence
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 %
What is the central nervous system?
- 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
What is the peripheral nervous system?
- Anything outside of the CNS that is responsible for senses and motor control
CNS: The brain
- 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
What are the folds in the brain called?
- Shallow canyon: Sulcus
- Deep canyon: Fissure
- Bits that pop out: Gyrus
CNS: Spinal cord
- 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
Examples of spinal cord injury
C2 injury (cervical) - Tetraplegia --> neck down C6 injury (cervical) - Tetraplegia --> chest down T6 injury (Thoracic) - Paraplegia -->stomach down L1 injury (Lumbar) - Paraplegia --> Hips down
Peripheral nervous system: Somatic
- Somatic nervous system is responsible for muscle control of body movements
Peripheral nervous system: Autonomic
- Autonomic nervous system controls bodily functions not consciously directed
- Parasympathetic nerves: “Rest and digest”
- Sympathetic nerves: “Fight or flight”
What is the endocrine system?
- Means of communication
- Secretes hormones
- Unlike the nervous system, relatively slow, longer-lasting messages
- Coordinates with the nervous system
Etymology of endocrine system
Endo = within Crine = secrete
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
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
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
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
Cortisol regulation
- Neural signal reaches the hypothalamus
- Hypothalamus releases corticotropin-releasing hormone
- CRF reaches thee pituitary gland
- Pituitary gland releases adrenocorticotropic hormone
- ACTH reaches adrenal medulla
- Cortisol produced