Brain and biology
- Brain: the four lobes and their functions
o Parietal: interprets language (words), sense of touch, pain and temp, interprets signals
from vision, hearing, motor, sensory and memory, spatial and visual perception
o
o
Temporal: understanding language, memory, hearing, sequencing and organization
Occipital: interprets vision (colour, movement, light)
o
Frontal: personality, behaviour, emotions, judgement, planning problem solving, speech
(speaking and writing), body movement, intelligence, concentration and self-awareness
-
Cerebrum: largest part of the brain. Higher functions (interpreting touch, vision, and hearing,
speech, reasoning, emotions, learning, and fine control of movement)
-
Cerebellum: coordinate muscle movements, maintain posture and balance
-
Brainstem parts: midbrain, pons, medulla. Acts as relay centre. Automatic functions
performance (breathing etc). 10/12 cranial nerves originate here
o
-
Midbrain (vision, hearing, eye movement, body movement), pons and medulla (last two
have centers for controlling vital body functions)
Deep structures:
o Hypothalamus: role in controlling behaviour (hunger, sleep, thirst, sleep and sexual
response), regulating body temp, BP, emotions and secretion of hormones
o
Thalamus: relay station for all info. Role in pain sensation, attention, alertness and
memory
o
Limbic system: thalamus (pain), hypothalamus (emotions, homeostasis), amygdala
(memory-emotion, fear), hippocampus (memory and learning)
-
Brain embryological structures: pro, mes, and rhomb.
-
NS: PNS (autonomic: Para and symp. and somatic) and CNS (spinal cord and brain)
-
o
Two structures in PNS: nerves and ganglion
o
4 types of cells in the NS: unipolar, multipolar, bi polar, anaxonic
o
Neuroglia of the CNS: astrocytes, oligodendrocytes, ependymal cells, microglia
o
Neuroglia of the PNS: Schwann cells and satellite cells
Intracellular fluid is – because organic and potassium ions
Extracellular fluid is + because sodium and chloride
-
Action potential steps: threshold of excitation, depolarization (influx of sodium),
hyperpolarization (potassium exits)
-
Functions of the NS: basic (lower) functions are motor, sensory and automatic vs complete
(higher) functions are cognition, memory, learning, language, emotions and consciousness.
o
Executive functions
-
Reflexes
-
Brain protected by 3 layers of meninges (dura mater, arachnoid mater and pia mater)
Sight and vision
-
Visible part of electromagnetic spectrum (400-700 nm)
-
Anatomy of the eye: sclera, choroid, cornea (lens, suspensory ligaments, ciliary muscles), pupil,
iris, aqueous humor, retina (outer pigmented and inner neuronal layer), rod cells and cone cells
(s, m and l cone cells as blue, green and red), fovea, optic disk
-
Light pathway: cornea- retina (rod cells and cones)-ganglion cells (action potential)-optic nervesthalamus-visual cortex
o
-
120 rods vs 6-7 million cones
Color blindness: monochromacy, red-green, achromatopsia, tetra chromatic vision
Smell-olfaction
- Anosmia (inability to smell)
-
Olfactory epithelium is the main organ
-
Smell molecules path: olfactory epithelium- olfactory neurons (glomerulus transfers nose info to
brain info)- mitral cells dendrites and soma- ethmoid bone-olfactory bulb- i. emotional ground
control (limbic system) ii. Frontal lobe for smell identification
Taste
-
Taste buds on tongue, packed between fungiform papillae
-
Taste sensations: sweet, salty, sour, bitter and umami
-
Food chemicals-tastants- gustatory cells- action potential
Skin senses
- Three main layers: epidermis (water-proof), dermis (sense of touch and heat from the
environment-nerve endings), hypodermis (attach skin to underlying bone/muscles + supplying it
with blood vessels and nerves)
-
Three distinct senses: pressure, temperature, pain
-
5 different receptors in the skin: Merkle cell disc, Meissner corpuscles, Pacinian corpuscles,
temperature, nociceptors
Pain perception
- Gate control theory of pain: thin diameter fibres (pain), thick diameter fibres (pressure, touch
and vibration). More activity in the thin fibres is what causes more pain sensation vs thick fibres.
These nerve fibres carry info to 2 areas in dorsal spinal cord: pain signal to the brain and
inhibitory interneurons that impede transmission cell activity
-
The neuromatrix theory of pain: pain stimulation from subjective experiences through a
network of neurons called the neuromatrix
-
Chronic pain: decreases grey matter of brain 2 X more than normal brain; pain lasts 3-6 months
without particular cause.
o
-
Psychological influences on chronic pain: psychosocial factors (stress mood, anxiety can
impede reporting of pain symptoms/response to treatment), psychological conditions
that lead to higher perception of pain (depression, anger, anxiety), increased brain
activity in the frontal cortex.
Biopsychosocial model/theory: genetics+ mental health/personality + sociocultural environment
= perception of health/illness.
o
Biopsychosocial interventions (5): psychological (CBT), biological pain management
(meds), somatic (injection therapy, acupuncture, manipulation, massages), relaxation
techniques (MBSR, biofeedback), body alignment/strengthening (physiotherapy, yoga)
Memory
-
Three key memory processes are encoding (encoding vs exact representation), storage and
retrieval.
-
Three stages of memory: sensory (iconic and echoic; echoic holds longer around 3 sec): average
is 2 sec), short term (central executive, phonological and visuo-spatial sketchpad: ~ 30sec and 7
items) and long term (25% STM goes into LTM).
-
Primacy-recency effect/serial position effect
-
Interference in memory recall: retrograde and proactive interference (old affects new).
-
Retrieval affected by interference, levels of processing, organization and context (SDM- state
dependent memory).
-
5 types of long-term memory: episodic, semantic, procedural, prospective and autobiographical
memory.
-
Recognition (sensing a stimulus has been previously encountered) vs recall (reconstruction of
the actual stimulus due to cues/LTM)
-
2 causes of forgetting: passage of time and interference.
-
2 types of amnesia: anterograde (inability to store new info) and retrograde (inability to recall
info prior to trauma).
Perception
-
Three ways to measure perception: qualitative, quantitative and subliminal priming.
-
Factors affecting perception: attention (attentional blindness and biases), illusion (geometric
illusion, ambiguous figures, fictitious perceptions)
-
Gestalt rules: form perception “figure ground relationship”. Grouping, similarity, continuity,
connectedness
-
Depth perception due to depth cues: linear perspective, interposition/superimposition/overlap,
shadows, texture gradient, and relative size.
-
Two theories explaining perception: the constructivist’s theory (top down processing) and the
nativists theory (bottom up processing)
Child development
-
Piaget’s stages of cognitive development: sensorimotor, preoperational, concrete operational,
and formal operations.
-
Erikson’s 8 stages of life span development
-
3 learning methods (children): equilibration, assimilation and accommodation.
-
Maslow’s Hierarchy of needs: Physiological (food, water, biological functions, sex), safety
(security of work, body etc.), love/belonging (friendship, family, sexual intimacy), esteem
(confidence, achievement, respect to others) and self-actualization (morality, creativity, problem
solving, lack of prejudice and acceptance of facts). PSLES
-
John Bowlby’s theory on attachment
o
Four major characteristics in attachment: proximity maintenance, safe haven, secure
base and separation distress
o
3 phase of attachment behaviour: 1rst phase, 2nd phase, 3rd phase
o
3 types of attachment behaviour: signalling, aversive, active behaviour
o
3 triggering sites for attachment: within child, within environment and within the
attachment figure
-
Strange situation procedure in 1970 by Mary Ainsworth: 7 steps, 3 minutes each. Four aspects of
child’s behaviour observed?
-
Four patterns of attachment: secure, anxious avoidant, anxious-ambivalent/resistant,
disorganized
-
Attachment disorders: Reactive attachment disorder (disinhibited pattern and inhibited
pattern), disinhibited social engagement disorder
Possible short answer questions
Psychosomatic problem- bodily functions
- Irritable bowel syndrome IBS
- Hypertension
- Tics and spasms
- Asthma
- Insomnia/sleep disorders
- Psychogenic vomiting
- Skin conditions
Patient interviewing guidelines
- Opening the interview
- Encouraging and prompting the patient
- Support and reassurance
- Showing empathy
Comments from patient’s perspective
- Lack of information
- Communication gap
- Poor recall
- Low empathy
- Activity/passivity
Comments from doctor’s perspective
- Low compliance
- Poor information
Health and related behaviour
- Daily behaviours with health implications (eg diet)
- Preventative behaviours (attending dental check-ups, screening)
- risk avoidance (stop smoking, limiting alcohol)
- specific behaviours in relation to symptoms and illnesses (self-medication, seeking medical help,
adhering to medical advice)
The 2 medical approaches
- biomedical
- biopsychosocial
biomedical approach does not consider:
- social factor
- psychological factors in health
stress response in GAS (general adaptation syndrome)
- initial alarm reaction stage
- resistance stage representing function recovery to a level superior to the stressor level
- exhaustion: if stressor continues, then there is depletion and breakdown of the recovery
progress activated in the pervious 2 stages
factors mediating response to stress
- major experience
- information
- individual differences
- perceived control
- social support
psychological factors and disease
- social class
- occupational factors
- lifestyle
biopsychosocial model considers:
- biological factors
- psychological factors
- social factors
this approach later included ethnicity and culture as factors as well! This approach looks at personal
(internal) and external factors that impact health
-
internal factors: personal history, psychosocial processes, physiological and biochemical
mechanisms