senses of the body

hearing, vision, taste, smell, touch, balance, thermoception, proprioception and pain.

senses of the body

hearing, vision, taste, smell, touch, balance, thermoception, proprioception and pain.

general senses vs special senses.

general are found all over the body and do not have their own specialised organs. specials are found only in the head and do not have their own specialised organs.

general senses vs special senses.

general are found all over the body and do not have their own specialised organs. specials are found only in the head and do not have their own specialised organs.

4 special senses.

hearing & balance, vision, taste and smell.

4 special senses.

hearing & balance, vision, taste and smell.

transduction definition.

sense organs have specialised sensory receptor cells that translate stimuli into electrical signals. this process is called transduction.

transduction definition.

sense organs have specialised sensory receptor cells that translate stimuli into electrical signals. this process is called transduction.

sensation vs perception.

a sensation is the raw input from the peripheral nervous system that arrives the central nervous system. a perception is the brain interpretation of a sensation.

sensation vs perception.

a sensation is the raw input from the peripheral nervous system that arrives the central nervous system. a perception is the brain interpretation of a sensation.

cornea & lens.

the cornea transmits and focuses light into the eye from different angles. the lens focuses light rays onto the retina. it is avascular and held in place by ligaments.

cornea & lens.

the cornea transmits and focuses light into the eye from different angles. the lens focuses light rays onto the retina. it is avascular and held in place by ligaments.

pupil & iris

iris: coloured part of the eye that helps regulate the amount of light that enters. pupil: dark aperture in the iris that determines how much light is let into the eye.

pupil & iris

iris: coloured part of the eye that helps regulate the amount of light that enters. pupil: dark aperture in the iris that determines how much light is let into the eye.

retina, macular & optic nerve.

retina: nerve layer that lines the back of the eye, sense light, and creates electrical impulses that travel through the optic nerve to the brain (peripheral vision). Macular: small central area in the retina that contains special light-sensitive cells and allows us to see fine details clearly (central vision). optic nerve: connects the eye to the brain and carries the electrical impulses formed by the retina to the visual cortex of the brain.

retina, macular & optic nerve.

retina: nerve layer that lines the back of the eye, sense light, and creates electrical impulses that travel through the optic nerve to the brain (peripheral vision). Macular: small central area in the retina that contains special light-sensitive cells and allows us to see fine details clearly (central vision). optic nerve: connects the eye to the brain and carries the electrical impulses formed by the retina to the visual cortex of the brain.

photoreceptors. rods and cones

rods: shades of grey in dim light. 120 million rod cells. allows vision for shapes & movements. distributed along the periphery. cones: specialised for clarity and colour. 6 million. found inside the macula.

photoreceptors. rods and cones

rods: shades of grey in dim light. 120 million rod cells. allows vision for shapes & movements. distributed along the periphery. cones: specialised for clarity and colour. 6 million. found inside the macula.

refraction of light.

bending of light as it passes from one substance to another (air) into a 2nd substance with a different density (cornea/lens).

refraction of light.

bending of light as it passes from one substance to another (air) into a 2nd substance with a different density (cornea/lens).

image focus.

image focused on retina is inverted & reversed from left to right brain corrects information. 75% of refraction is done by the cornea, 25% is done by the lens.

image focus.

image focused on retina is inverted & reversed from left to right brain corrects information. 75% of refraction is done by the cornea, 25% is done by the lens.

vision distance.

if distant vision is required, the ligaments are pulled tight and the lens flattens. if close vision is required, the ligaments are loosened and the lens bulges. as we age our lens becomes less elastic, causing presbyopia.

vision distance.

if distant vision is required, the ligaments are pulled tight and the lens flattens. if close vision is required, the ligaments are loosened and the lens bulges. as we age our lens becomes less elastic, causing presbyopia.

force depends on..

neural drive, motor unit behaviour and coordination.

muscular vs neurological adaptation to a exercise program.

"noobie gains" are actually neurological adaptations not muscle growth. happens during 1-4 weeks of training. 4 weeks+ hypertrophy contributes more.

rate coding types.

temporal summation & tetanic force generation.

motor unit firing types.

independently / Asynchronsly (normal). more synchronously (trained/high force). effects of synchronisation: higher peak force, lower smoothness of force.

inhibition and neural drive.

with training, the nervous system reduces this inhibition and increases neural drive.

muscular power is...

the product of force and velocity. through full range of motion.

v-wave definition.

recurrent inhibition.

An overide, where we activate a muscle and recruit other motor units. a chronic adaptation to training.

brain adaptation to training.

motor cortex activation and motor learning. increased neural drive. and c=decreased inhibitory control.

spinal adaptations to training.

training alters: reflex sensitivity and modulation depending on task. sensorymotor integration. motor neural excitability. outcomes of training: faster and more efficient responses.

peripheral/motor unit adaptations to training.

increase in recruitment capacity, firing frequency (rate coding), and synchronisation. outcomes of training: force production and efficiency.

nervous system when detraining.

decreased neural drive, motor unit recruitment and firing rate.

recovery after nervous system injury.

injury disrupts: movement, coordination, sensory processing. Recovery depends on: neuroplasticity, reorganisation, motor relearning.

recovery of neurons.

reorganisation of neural pathways, strengthening of existing connections and motor relearning through repetition. recovery is adaptive, task specific, and experience dependant.

senescence definition.

the biological process of aging. gradual deterioration of functions.

synaptogenesis definition.

what is pain?

unpleasant and emotional sensation associated with actual or potential tissue damage.

the two types of pain.

nociceptive pain - activation of nociceptors in response to potential or actual tissue damage e.g. burns, muscle strain, stained ankle. Neuropathic pain - caused by lesion or dysfunction of the nervous system itself e.g. sciatica, diabetic neuropathy.

types of nociceptors.

-thermal (myelinated Alfa delta fiber) activated by temperatures >45C or <5C. -Mechanical (myelinated Alfa Delta) activated by intense pressure applied to skin. -Polymodal (activated by high-intensity mechanical, chemical, or thermal stimuli.

Pain pathways.

- spinothalamic tract - Spinoreticular tract - Spinoparabrachial tract - Spinohypothalamic tract

gate control theory

relative balance of activity in nociceptive and non-nocireceptive afferents might influence the transmission and perception of pain. touch stimulus causes pain receptor not to fire as much/be less sensitive.

referred pain.

neuropathic pain breakdown.

pain my occur without ongoing tissue damage. the nervous system itself becomes the source of abnormal signalling.

central sensitisation.

increased excitability of neurons within the central nervous system. particularly within dorsal horn and higher pain pathways. after repeated or prolonged nociceptive input: dorsal horn neurons become more excitable, inhibitory control decreases & pain pathways become easier to activate.

chronic pain and neuroplasticity.

pain, fear and movement.

implications for rehabilitation (pain).

- Reduce nervous system sensitisation. - normalise movement patterns. - promote neuroplasticity. - reduce threat and fear. - restore function and participation. - improve sensory feedback.

causes of neurological conditions.

Alzheimer's disease in depth.

progressive neurodegenerative disorder. deterioration of cognitive function and memory. neuronal degeneration. cortical atrophy. disrupted neural communication. driven by abnormal accumulation of proteins that disrupt communication between neurons, cause inflammation and lead to widespread brain atrophy. Synaptic loss and cell death typically start in the hippocampus, destroying memory before spreading. starts in the hippocampus (loss of memory). Amyloid plaques (outside the cell) & Tue tangles (inside the cell) build up around neuron.

Parkinson disease.

neurodegenerative disease affecting neural movement regulation. creates difficulty in the initiation of movement.

Multiple Sclerosis.

chronic autoimmune disease of CNS. Causes immune system to attack and degenerate myelin.

ALS) Amyotrophic Lateral sclerosis.

degeneration of upper and lower motor units. lead to death eventually. only affects motor neurons, not sensory neurons. degeneration of corticospinal pathways, upper motor neurons, lower motor neurons in the spinal cord and brainstem.

stroke.

stoppage of blood supply to brain causing rapid neural dysfunction and neural death.

Cerebral palsy.

movement disorder caused by abnormal brain development or injury during early development.

Traumatic Brain Injury.

impact. mechanical forces can cause: neural injury, axon stretching, disrupted synaptic communication, altered cortical function.

concussion.

disruption known as neurometabolic cascade of concussion. causes microscopic cellular changes.

principles of neurorehabilitation.

Neuroplaticity repetition task specificity sensory feedback progressive overload motor learning