Definitions:

  • SLEEP
    • reversible behavioural state of unresponsiveness & perpetual dissociation from the environment
  • CONSCIOUSNESS:
    • Perception of sensations, voluntary initiation & control of movement, capabilities associated with higher mental processing

Stages of consciousness

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Sleep

  • Not a period of absolute rest
    • some parts of the brain are more active during sleep
    • Dreams
      • necessary
      • Experiments where people have been awakened as they enter the REM sleep phase become moody & depressed, and disoriented; and may have hallucinations
  • Purpose of sleeping
    • Restorative
      • especially slow wave sleep
    • Conservation of energy
    • Maintaining adequate function of the immune system
    • Mentally practise & refine behaviour
      • e.g. escaping from predators without actually having to perform them
    • REM sleep
      • we dream to forget
      • reverse learning helps us forget trivial things
      • and to sort out our emotions
  • Physiological changes in sleep
    • Decreased reaction to external stimuli
    • Reduced activity of the sympathetic system
      • Parasympathetic dominance
      • Reduced heart rate, BP, respiratory rate
        • especially in Non-REM sleep
      • Reduced metabolic rate
        • Somnolent Metabolic Rate (SMR)
          • is lower than BMR
    • Reduced muscle tone
      • Extensor  Babinski response
        • unmasking of extensor dominance
    • Changes in EEG
    • Increased growth hormone production during deep sleep
      • decreased in REM sleep

Sleep cycles

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  • First cycle:
    • descends from stage 1-2-3-4
    • resurfaces from 3-2-1
    • enters REM-descends intom2-3-4 and so on
  • Subsequent cycles become shorter
  • The cycle ends with REM sleep
  • In adults, sleep begins with NREM
    • in infants it begins with REM
    • REM-onset sleep is seen in adults in
      • jet lag
      • chronic sleep deprivation
      • acute withdrawal of REM-suppressing drugs
      • endogenous depressinarcolepsyon
  • Retrograde amnesia
    • poor recall of midnight dreams
    • not remembering clock ringing

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  • Awake
    • Alert
      • Beta wave
    • Resting
      • Alpha wave
  • Sleep
    • Stage 1
      • Theta wave
    • Stage 2
      • Spindles
      • K complex
    • Stage 3
      • Delta wave appears
    • Stage 4
      • Delta wave
        • Also seen in deep sleep/ anaesthesia / brain damage in awake adults
      • Synchronisation
    • REM Sleep
      • Ponto-geniculo-occipital (PGO) spike

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Difference between deep sleep and REM sleep

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Changes in pattern of sleep with age

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  • With age
    • REM sleep decreases
    • deep sleep decreases
  • Total sleep time decreases

Regulation of sleep

  • Sleep is regulated by
    • an interaction of homeostatic and circadian processes
    • The homeostatic mechanisms
      • keep track of how long we have been awake and asleep
      • how tired we are!
    • The circadian process
      • determines the optimal time for sleep
  • They influence sleep duration and the relative contribution of the two major types of sleep:
    • non-rapid eye movement (NREM)
    • rapid eye movement (REM) sleep

The circadian process

  • Circa=about , dian=day
  • The suprachiasmatic nucleus (SCN) dictates the sleep-wake cycles over a roughly 24-hour period
    • the SCN receives inputs via the retino-hypothalamic fibres
      • is  influenced by external cues (e.g daylight)
      • but the rhythm is still present in volunteers kept in caves or in people blind from birth
      • Light initiates sleep in nocturnal animals & waking in diurnal animals (including humans)
  • Melatonin & melanopsin may play a role
    • Phase shifts can occur with rapid crossing of time zones
      • resulting in ‘jet lag’

The ultradian process

    • that is characterized by the alternation of the two basic sleep states non-rapid-eye-movement (NREM) sleep and REM sleep
      • influenced by SCN input

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  • Nucleus reticularis pontis oralis – have 4 nuclei
    • PGO-on
      • causes PGO spikes associated with REM sleep
    • REM-on (stimulatory)
      • atonia of muscles during REM sleep
    • REM-on (inhibitory)
      • inhibits the 2 nuclei inhibiting PGO-on
    • REM-waking on
      • eye movements
      • muscle twitches
  • Hypothalamus – have 1 nuclei
    • NREM-on

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Sleep disorders

  • Transient relief with “sleeping pills”
    • benzodiazepines
    • but daytime performance may be compromised

Insomnia

  • Definition
    • chronic inability to maintain the amount/quality of sleep to function normally in the day
    • due to medical or mental conditions
  • Right amount of sleep
    • sleep requirements vary from 4-9 hours between individuals
    • Margaret Thatcher & Napoleon need(ed) only 4 hours of sleep
  • Fatal familial insomnia
    • autosomal dominant inheritance
    • Features
      • worsening insomnia
      • impaired ANS & motor functions
      • dementia
      • death
  • Types of insomnia
    • Onset sleep insomnia
      • difficulty in falling asleep initially
      • associated with anxiety disorders
    • Maintenance sleep insomnia
      • wake up middle of the night
      • difficulty in remaining asleep
        • with frequent awakening at night
      • may get back to sleep
      • associated with
        • pain disorders
        • medical illness
    • Terminal (late) insomnia
      • persistent early morning awakening
      • cannot get back to sleep
      • characteristic of clinical depression

Sleep deprivation

  • Marked by brief psychosis but non-permanent psychological effects
  • Features
    • irritability
    • stimuli misperception
    • decreased waking alpha activity
    • disorientation
    • lack of attentiveness
    • Neurological consequences
      • tremors
      • seizures

Narcolepsy

  • Definition
    • a chronic neurological disorder caused by the brain’s inability to regulate sleep-wake cycles normally
      • excessive daytime sleepiness (EDS)
  • Narcolepsy results from
    • disease processes affecting brain mechanisms that regulate REM sleep
  • For normal sleepers a typical sleep cycle is about 100 – 110 minutes long, beginning with NREM sleep and transitioning to REM sleep after 80 – 100 minutes
    • But, people with narcolepsy frequently enter REM sleep within a few minutes of falling asleep
  • Three other major symptoms frequently characterize narcolepsy
    • Cataplexy
      • the sudden loss of voluntary muscle tone
    • Vivid hallucinations
      • during sleep onset or upon awakening
    • Brief episodes of total paralysis
      • at the beginning or end of sleep 

Somnambulism (sleep walking)

  • more common in
    • children
    • males
  • may last a few minutes
  • walk with eyes open
    • to avoid collision
    • but cannot remember anything
  • Occur during arousal from slow wave sleep
    • somnambulism
    • noctural aneuresis
      • bed-wetting
    • night terrors
  • Nocturnal emission
    • Wet-dreams
    • normal in male (sometimes females) of reproductive age

Sleep apnoea

  • Definition
    • stopping of breathing for short periods
      • typically between 10 and 90 seconds) during a normal nightly sleep
  • Can be repeated hundreds of times during a sleep period
  • Almost always accompanied by
    • snoring, which is usually quite loud
  • Patient is  unaware of this happening, in normal circumstances
  • 3 types of sleep apnoea
    1. Obstructive sleep apnoea (OSA)
      • Fairly common
      • upper airway collapses as the throat muscles relax during normal sleep
      • cerebral hypoxia results in waking up
        • may be repeated every 15 minutes
      • May result in
        • excessive daytime tiredness and a lack of concentration
      • Counter-measure
        • Relieve the obstruction
          • sleep on the side; reduce weight
    2. Central
      • Rare
      • Neurological dysfunction
        • the brain simply "forgets" or "delays" to send the signal to breathe
      • More difficult to treat
        • some drugs may help
    3. Mixed
      • Extremely rare

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Reticular Activating System (RAS)

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  • The reticular formation resides in the brain stem
    • midbrain, pons & medulla
  • Comprised of the
    • motor system (reticulospinal system)
    • sensory systems (RAS)
    • the vital centres
  • The RAS stimulates the whole brain to cause arousal (wakefulness)
    • its output is suppressed in sleep & coma
    • stimulated by
      • input from the cortex (corticofugal fibres)
      • OREXINS
        • peptides released by hypothalamic neurons just before waking

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Consciousness

  • Various definitions
    • mind
    • awareness
    • ability to respond
  • Can it be equated to activity in the EEG?
  • Sometimes, people under general anaesthesia feel the pain and are conscious of their surroundings
    • but cannot convey this to the outside world , trapped in their own body
  • Perception of sensations, voluntary initiation & control of movement, capabilities –> associated with higher mental processing
  • The brain’s ability to adjust its activity and consciousness levels can be impaired in several ways:
    • When people are severely deprived of sleep
    • When and immediately after a seizure occurs
    • When both cerebral hemispheres are suddenly and severely damaged
    • When the reticular activating system malfunctions
    • When blood flow or the amount of nutrients (such as oxygen or sugar) going to the brain decrease
    • When toxic substances impair the brain (liver & kidney failure)
    • Drugs
      • morphine
      • diazepam
      • antipsychotic drugs
  • Periods of impaired consciousness can be short or long. The level of impairment can range from slight to severe:
    • Lethargy
      • slight reduction in alertness or clouding of consciousness
      • People tend to be less aware of what is happening around them and to think more slowly
    • Obtundation
      • moderate reduction in alertness or clouding of consciousness
    • Stupor
      • excessively long or deep sleep-like state
      • A person can be aroused from it only briefly by vigorous stimulation
        • such as repeated shaking, loud calling, pinching, or sticking with a pin.
    • Coma
      • state of complete unresponsiveness
      • A person cannot be aroused at all
      • A person in a deep coma lacks even the most basic responses, such as avoidance of pain
        • although reflexes may be present

Coma 
(read coma lecture notes)

  • In coma, brain oxygen utilisation is below normal resting levels
    • in sleep, the brain is active and oxygen consumption is comparable to the waking state
  • Caused by
    • trauma
    • tumours
    • metabolic disorders
      • hypoglycaemia (hyperosmolar coma)
      • drug overdose
      • liver and kidney failure
      • fluids & electrolytes imbalance
        • hypernatraemia
        • hypokalaemia
        • water intoxication
      • myxoedema
  • Depression of the reticular activating system (RAS)
  • Clinically assessed using Glasgow Coma Scale (GCS)
  • Four Score Coma Scale
      • eye & motor responses
      • brain stem reflexes
      • respiration. 
        Total unresponsiveness to sensory stimuli for an extended period

Courtesy: Imueos

Integrated function

Cerebral cortex

  • Voluntary movement
  • Language
    • Language area= left hemisphere
    • Wernicke’s area
      • superior & posterior portion of the temporal lobe
      • LANGUAGE COMPREHENSION
        • comprehension of written words, sounds, signs
      • Wernicke’s aphasia
        • can speak, but makes no sense
        • eg. says “chicken’ when pictures of chairs
    • Broca’s area
      • Frontal lobe
      • LANGUAGE EXPRESSION
        • speak/write word
      • Broca’s aphasia
        • can comprehend, but cannot speak
        • Can identify trees,  chairs etc but cannot say it
  • Emotions & motivation
    • 4 components
      • Cognition
      • Affect (feelings)
      • Conation (urge to take action)
      • Physical changes (BP, HR changes, sweating)
    • Inputs from
      • Memory
      • Special senses
    • Relayed in
      • Limbic cortex
      • hypothalamus
    • Anger & Aggression
      • Cerebral cortex
      • limbic system
      • hypothalamus
    • Fear & Anxiety
      • Amygdala
    • Motivation
      • impulse that drives our action
      • Physiological changes/pleasure derived from stimulation of “pleasure centres” which activate dopaminergic neurones
      • Reward/ Approach system
        • Cocaine appears to act here
      • Avoidance associated with lateral portion of posterior hypothalamus, dorsal midbrain & entorhinal cortex
        • punishment/ avoidance system
  • Sleep
  • Learning & Memory
    • Learning: acquisition of new memory/skills
    • Memory: retention of information/skills/thoughts
    • 2 types of learning
      • Associative
        • Connections between two or more stimuli
        • eg. Conditioned Reflexes (Pavlov’s dogs)/use of mnemonics/learning hands-on that fire is hot
      • Non-associative
        • Repetition
        • Habituation
          • reduced responses to repeated stimuli
        • Sensitisation
          • increased response
        • Habituation/ sensitisation
          • depends on how important it is to us
          • eg. a mother sleeps through loud noises but wakes up at her baby’s cry
    • 2 types of memories
      • Non-declarative, implicit, reflexic
        • Memory of learned skills ( & habits)
          • eg. riding a bicycle/route to home
        • Simple classical conditioning
        • Priming
        • Stored in several areas including
          • Cerebellum
          • Basal nuclei
          • Pons
        • Once learnt, do not require a conscious effort of recall
      • Declarative, explicit
        • Memory of learned experiences
          • facts or figures
          • eg. recite the alphabet, remember birthdays
        • Short-term memory
          • consolidated into long-term memory
          • in hippocampus (encoding in HIPPOCAMPUS)
        • Long-term memory stored in
          • various parts of the neocortex
          • stimulation of implanted electrodes plays back memories
        • Amygdala add emotional colour to memories
    • Areas of the brain associated with memory
      • Working/short term memory
        • frontal lobe
      • Long term memory
        • hippocampus
      • Habits & skills
        • cerebellum
        • basal nuclei

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Cerebral lobes

  • Damage to frontal lobe
    • reduced anxiety
    • personality changes
      • unpredictable
      • uninhibited social behaviour
    • epilepsy
  • Damage to parietal lobe
    • Agnosia
      • Loss of cognition
      • No sensory deficit
        • but fails to recognise objects
        • Visual Agnosia
          • can recognise through touch but not by vision
        • Astereognosis
          • cannot recognise by touch
    • Apraxia
      • loss of ability to perform specific purposeful movements
        • cannot wave goodbye, but can perform that act spontaneously
      • Constructional apraxia
        • Failure to use everyday objects appropriately or construct/draw a simple object
      • Kinetic apraxia
        • Deficit in the control of movements of one hand caused by damage to the premotor area of the frontal lobe of the opposite side
    • Neglect syndrome
      • stroke in posterior region of right hemisphere
      • cannot perform left hand side functions

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Limbic system (Rhinencephalon)

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  • Rim of cortical tissue around the hilum of the cerebral cortex and associated deep structures (amygdala, hippocampus & septal nuclei)
  • Plays a role in
    • ANS functions
    • Olfaction
    • Feeding behaviour
    • Sexual behaviour
    • Rage & fear
    • Motivation
  • Principal connections of limbic system
    • Hippocampal system
      • hippocampus-fornix-mamilary body- ant.thalamic nuclei- cingulate cortex- hippocampus
    • Olfactory & amygdaloid connections

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Memory

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Encoding (of memory)

  • Not known how
    • Repetition
    • How important it is to you also counts
      • eg. you get married only once, but remember the date
  • Short -term memory
    • stored in the frontal lobe but only temporarily (a few seconds to a few minutes) 
    • the information needs to be consolidated into long-term memory
      • because the space is limited
  • Long-term memory
    • resides in the hippocampus
    • lasts years/ lifetime
  • Forgetting is an essential part of learning
  • Cases of herpes simplex attacking the brain
    • hippocampus
  • Brain surgery performed to relieve epileptic seizures
    • very short memory span
    • but can recall long-term memories

Long term potentiation (LTP)

  • Because of the property of plasticity
    • ability to alter the anatomy and function in response to changes in its activity patterns
    • new neurons are produced in the areas involved in memory
  • Long term potentiation
    • repeated stimulation results in increased strength of that synaptic connection
      • increased number of EPSPs
      • Brief patterned stimulation leads to a long-lasting increase in the efficacy of synaptic transmission lasting minutes to hours!
    • Memory improves with repetition
  • First seen in hippocampus (encoding)
    • Consolidation of long-term memory

Conditioned reflexes

  • Reflex response to a stimulus that previously elicited no response
    • by repeatedly pairing the stimulus with another stimulus that normally produces the response
      • Eg. Salivation (response) occurs when meat is placed in the mouth
        • Unconditioned stimulus (US)
      • Ringing of bell which normally does not cause salivation
        • conditioned stimulus (CS)
        • before placing the meat in the mouth
      • Repeatedly doing this results in salivation when the bell is rung
  • US combined with pleasant or unpleasant effect helps to establish the conditioned reflex
    • Positive & Negative reinforcement
  • If the CS is presented repeatedly without US
    • the conditioned reflex eventually dies out
      • Extinction/Internal inhibiton
  • Operant conditioning
    • taught to operate the environment to obtain a reward or avoid punishment
      • CS is a light or other signal that alerts the animal to perform a task
      • US is the pleasant or unpleasant event
        • eg. light- electric shock
        • can be prevented by pressing a bar

Circadian rhythm

  • Rhythms < 24 hours- ultradian
    • e.g. heart beat, respiratory cycle
  • Rhythms > 24 h – infradian
    • e.g. menstrual cycle, gestation
  • Peripheral clocks/rhythm generators
    • exist in many tissues
    • but the ‘master clock’ is the suprachiasmatic nucleus (SCN)
  • Circannual rhythms
    • yearly rhythm
    • e.g. breeding, hibernation, migration
  • Endogenous Rhythms
    • dictated by the “Biological Clock”
      • suprachiasmatic nucleus (SCN)
    • But influenced by exogenous cues
      • Entrainment by social and physical cues
  • Pineal gland produces melatonin in the dark
    • drowsiness, loss of alertness
    • Useful to minimise
      • Jet lag 
      • Seasonal Affective Disorder in winter

Classification of bones

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  • Long bones
    • bones of the limbs
  • Short bones
    • carpal
    • tarsal
  • Flat bones
    • Frontal
    • Parietal
    • Occipital
    • Squamous part of temporal
  • Irregular bones
    • Vertebrae
    • hip bones
  • Short long bones
    • metacarpal
    • metatarsal
  • Sesamoid bones
    • Patella
    • Pisiform
  • Pneumatic bones
    • Maxilla
    • Part of frontal air sinus

Skeleton

  • Axial skeleton (80)
    • skull
    • vertebral column
    • ribs
    • sternum
  • Appendicular skeleton (126)
    • pectoral girdle
    • upper limb bones
    • pelvic girdle
    • lower limb bones

Microscopic structure of the bone

 

 

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  1. Haversian system
  2. Haversian canal
  3. Outer circumferential lamellae
  4. PeriosteumInterstitial lamellae
    • contains osteoblasts
    • endosteum also have osteoblasts
  5. Osteocytes
  6. Cancellous bone

*Read up from foundation 1

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Osteoblasts are at the periphery forming osteocytes.image  
Parts of a growing lone bone

  • Epiphysis
  • Diaphysis
  • Epiphyseal plate (of cartilage)
  • Metaphysis

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The growth of bone in the epiphyseal plate

 

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Before epiphyseal closure, Metaphysis is richly supplied with blood through end arteries forming hair-pin bends. This is a common site of osteomyelitis in children, because bacteria or emboli easily gets trap in the hair-pin bends, causing infarction.

After epiphyseal closure, the vascular communications are established between the metaphyseal and epiphyseal arteries. Therefore, osteomyelitis will not occur after epiphyseal closure, especially in adults.

Arteries supplying a developing long bone

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Primary centre of ossification

  • Diaphysis
    • prenatal

Secondary centre of ossification

 Epiphysis

    • postnatal
    • chrondrocytes form cartilage
      • no blood supply in cartilage so die, and then osteoblasts will calcify dead cartilage
      • hyaline – articular cartilage, depends on synovial fluid to get nutrition
        • when synovial fluid runs out – forms osteoarthritis
    • the growing end is the end of the bone where it appears earlier but fuses later
      • lower end of radius and ulnar & upper end of humerus
      • lower end of femus & upper end of tibia and fibula
      • importance
        • amputation end is growing end (20 years or younger)
        • leave an additional skin to allow the bone to grow
        • or not, skin will be torn from the growing bone after amputation

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Cretin has a bone age of a 5 year old. She has a developmental abnormality.

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Radiologists determine the bone age by looking at xray of the wrist and teeth.

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Bones of Upper Limbs

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  • Curvature of clavicle
    • middle 2/3 & lateral 1/3
    • many fractures happens here
  • clavicle supported by
    • coraco-clavicular ligament
      • conoid part
        • connect coracoid process with clavicle
        • bears the weight of upper limbs
        • so if ligament ruptured, clavicle difficult to heal
      • trapezeoid part

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Clavicle fracture

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Abduction of shoulder

  • Every 3 degree abduction
    • 2 degree at shoulder joint
      • TOTAL (out of 180 degree): 120 degree btwn glenoid & humerus
    • 1 degree scapular forward rotation at acromio-clavicular & sterno-clavicular joint
      • TOTAL: 60 degree

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  • true shoulder joint
    • glenohumeral joint
  • coraco-acromial arch (false shoulder joint)
    • coracoid process
    • acromion process
    • coraco-acromial ligament

 

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  • Below clavicle there is a fascia
    • clavi-pectoral fascia
      • strong
      • pierced by cephalic vein
      • between pectoralis minor muscle and clavicle

Scapula

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  • Borders
    • Medial border
    • Lateral border
    • Inferior border
    • Superior border
  • Angles
    • Superior angle
    • Inferior angle
  • Fossa
    • Anteriorly
      • Subscapular fossa
      • Supraglenoid fossa
      • Glenoid fossa
    • Posteriorly (relation to spine of scapula)
      • Supraspinous fossa
      • Infraspinous fossa
  • Other parts of the scapula
    • Scapular notch
    • Coracoid process
    • Acromion process
    • Spine of scapula

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Posterior view of the humerus

  • Anatomical neck
    • junction point between head and tubercle
  • Surgical neck
    • in btwn diaphysis and head + tubercle
  • 3 important nerve
    • Axillary nerve
      • surround the surgical neck
      • supply the deltoid
      • fracture of surgical neck/inferior dislocation of shoulder
        • paralysis of deltoid
        • atrophy of deltoid
    • Radial nerve
      • radial groove/fossa
      • radial nerve runs in middle 3rd of humerus
      • suffering from osteogenic sarcoma, compression of radial nerve, fracture middle 3rd of humerus, saturday night palsy (temp effect)
      • extension of wrist
        • paralysis due to fracture of middle 3rd of humerus
          • wrist flexed always
            • wrist drop
    • Ulnar nerve
      • lies behind medial epicondyle
      • intrinsic muscle of the hand
        • paralysis if fracture medial epicondyle

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  • Axillary nerve paralysis
    • subluxtion of shoulder as loss of abduction has caused shoulder to come down under the weight of the upper limbs

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  • Radial nerve injury
    • wrist drop

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  • Trochlea
    • form humero-ulnar joint
  • Capitulum
    • forms which joint?

 

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  • Radial tuberosity
    • insertion of the biceps
    • flexor of elbow
  • Ulnar tuberosity
    • insertion of brachialis
    • flexor of elbow
  • Styloid process of radius always lower than styloid process of ulnar
    • why?
      • most common fracture of upper limb at lower end of radius
      • altered position
        • if styloid process of radius is higher
          • colles fracture
          • dinner fork deformity

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  • Carpal bones
    • dont need to know all the carpal bones
      • not important
    • What forms the wrist joints?
      • lunate
      • scaphoid
      • triquetrum
      • lower end of radius
        • NOT INVOLVING ULNAR AT ALL
  • 1st carpal-metacarpal joint (CMC joint)
    • trapezium & 1st metacarpal joint
    • saddle type of joint

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  • Ligament of flexor retinaculum, covering the
    • scaphoid
    • trapezium
    • piciform
  • Carpal tunnel
    • in btwn flexor retinaculum ligament and the carpal bones
      • All the tendons go into it
      • 1 structure is compressed
        • median nerve
        • carpal tunnel syndrome
          • loss of sensation – lateral 3 1/2 of fingers
          • atrophy of thenar muscle

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  • Carpal tunnel, loss of sensation in the shaded area
    • lateral 3 1/2 of fingers

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Bones of the lower limbs

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Pelvic Girdle

  • Bony ring
    • formed by 2 hip bones
    • joined at symphysis pubis & sacrum
  • Symphysis pubis
    • Secondary cartilaginous joint
      • fibrocartilage disc
  • Sacroiliac joint
    • between sacrum and ilium
    • Plane type synovial joint
      • transmit weight of trunk to each femur
      • weight bearing joint *
  • Inguinal ligament
    • between anterior superior iliac spine (ASIS) & pubic tubercle
      • forms fold of groin
    • attachment of bony surfaces
    • separates abdomen & lower limb

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  • 3 parts
    • Ilium
    • Ischium
    • Pubis
  • Relationship
    • Posterior superior iliac spine
      • dimple of venus
    • Anterior inferior iliac spine
      • iliofemoral ligament attachment
        • strongest ligament in the body
        • maintains integrity of hip joint
          • especially when hip joint is injured
    • Greater sciatic notch
      • sciatic nerve runs through it
    • Lesser sciatic notch
      • pudendal nerve runs through it
    • Sacrotuberous ligament
      • important for perineal muscle – reproductive system
    • Ischial tuberosity
      • origin of hamstring muscles
        • flexor of knee
        • extensor of hip
    • Gluteus maximus
      • extensor of hip
    • Gluteus medius
      • abductors of hip
    • Gluteus minimus
      • abductors of hip
    • Acetabulum
      • covered with acetabulum labrum
      • socket of hip joint
        • holds head of femur

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  • Greater Sciatic notch
    • Becomes greater sciatic foramen by Sacro-tuberous ligament
    • Through this foramen, Sciatic nerve passes down into back of thigh with:
      • Superior Gluteal nerve
      • Inferior Gluteal nerve
      • Pudendal nerve
        • reenters through lesser sciatic notch
        • supplies the perineal organs
  • Lesser Sciatic notch
    • Contains pudendal nerve
      • reenters the pelvis

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  • Greater trochanter
    • attaches Gluteus medius & minimus
      • abductor of the hip
    • intertrochanteric neck of femur fracture
      • below the neck of femur
      • cross the greater trochanter
      • paralyses abductor muscles of the hip
  • Lesser trochanter
    • attaches ilio-psoas muscle
      • flexor of the hip & vertebral column

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  • Piriformis muscle
    • demarcates the sciatic notch
      • Above
        • superior gluteal nerve & vessel
      • Below
        • inferior gluteal nerve & vessels
        • sciatic nerve

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  • Capsule of hip joint strengthened by
    • iliofemoral ligament
    • ischiofemoral ligament
    • pubofemoral ligament
      • therefore dislocation almost impossible
  • Ligament of head of femur
    • ligamentum capitis femoris

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Congeniral Hip dislocation (Putti’s Triad)

  • occurs in children
    • 5% of OPD female
  • acetabulum not formed
    • head of femur displaced
    • therefore there will be dislocation of the hip

Neck of femur fracture

  • arteries passing through
  • Neck of femur fracture
    • Proximal: head of femur
      • no important muscles
      • not much of a problem
    • Distal: total lower limbs
      • shortening of lower limb
      • muscle act on distal fragment
        • no abduction, so only adduction
  • If it is a subcapital intertrochanteric fracture (distal to neck to femur)
    • which is below the the neck of femur
      • across the greater trochanter
    • there will be avascular necrosis of the head of femur
      • cut off blood supply
    • paralyses abductor muscles of the hip
      • gluteus medius and minimus

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Limb length deformity

  • Coxa vara
    • greater the degree of coxa vara
      • shorter the length of the limb
    • includes all forms of decrease of the femoral neck-shaft angle to less than 120 degrees
    • due to
      • congenital rickets (most common)
      • fibrous dysplasia
      • epiphyseal injury
  • Coxa valga
    • greater the degree of coxa valga
      • longer the length of the limb
    • deformity of the hip where femoral neck-shaft angle is usually above 135 degrees

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  • Linea aspera
    • only found in human
    • thickened because we are bipedal

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  • Tibial tuberosity
    • attachment point for
      • quadriceps femoris muscle
      • patellar ligament

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  • What are the intra-articular structures in the knee joint?
    • meniscus
    • anterior & posterior crucial ligament
      • attached in intercondylar fascia

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Tibia & Fibula

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  • There is a nerve around the neck of fibula
    • common peroneal nerve/common fibular nerve
    • most common nerve affected in diabetic neuropathy

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Bones of the foot

Need to know all the Tarsal bones:

  • Hindfoot
    • Talus
      • connects to the tibia and fibula
        • to form ankle joint (talocrural joint)
      • parts
        • trochear
        • neck
        • head
    • Calcaneus
      • connects to talus via the subtalus joint
  • Arches of the foot (shock absorber)
    • Cuboid
      • lateral
      • articulates with 4th & 5th metatarsals
    • Navicular
    • 3 Cuneiform
      • Medial, intermediate and lateral
      • articulate with 1st, 2nd & 3rd metatarsals

Metatarsal bones

  • medial to lateral

Phalanges

  • distal, medial and proximal

 Arches of the foot

  • Longitudinal lateral
    • calcaneous
    • cuboid
    • 4th & 5th metatarsals
  • Longitudinal medial
    • calcaneous
    • talus
    • navicular
    • 3 cuneiforms
    • 1st, 2nd & 3rd metatarsals

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Ankle joint

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Ankle joint

  • Hinge joint
  • formed by articulation of the talus with the malleoli of the tibia and fibula
    • Trochear surface of talus
      • articulates with lower end of tibia
    • Comma-shaped articular surface of medial side of talus
      • articulate with medial malleolus of tibia
    • Triangular articular surface of lateral side of talus
      • articulates with lateral malleolus of fibula
    • Inferior transverse tibio-fibular ligament
      • forms posterior aspect of tibio-fibular mortice

 

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  • Talonavicular joint
    • between navicular tarsal bone and talus
  • Subtalar joint
    • between talus and calcaneus
  • Hallus valgus
    • change of alignment of great toe

Allignment of the foot

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  • Pes Planus (flat foot)
    • congenital
    • medial longitudinal arch may be poorly developed
    • difficulty in long distance walking/ running
    • causes:
      • weak plantar ligaments
      • weak muscles
  • Pes Cavus (exaggerated arch)
    • associated with neurological disorders
    • overactive peroneus longus
  • Congenital deformities
    • Talipes Equinus
      • marked plantar flexion
    • Talipes Varus
      • foot inverted and adducted
    • Talipes Valgus
      • foot everted and abducted

X-Ray – Learn up!

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Courtesy: Imueos

Science News

Nov. 5, 2013 — Two knee surgeons at University Hospitals Leuven have provided the first full anatomical description of a previously enigmatic ligament in the human knee. The ligament appears to play an important role in patients with anterior cruciate ligament (ACL) tears.

Despite successful ACL repair surgery and rehabilitation, some patients with ACL-repaired knees continue to experience so-called 'pivot shift', or episodes where the knee 'gives way' during activity. For the last four years, orthopaedic surgeons Dr Steven Claes and Professor Dr Johan Bellemans have been conducting research into serious ACL injuries in an effort to find out why. Their starting point: an 1879 article by a French surgeon that postulated the existence of an additional ligament located on the anterior of the human knee.

That postulation turned out to be correct: the Belgian doctors are the first to provide a full anatomical description of the ligament after a broad cadaver study using macroscopic dissection techniques. Their research shows that the ligament, called the anterolateral ligament (ALL), was noted to be present in all but one of the 41 cadaveric knees studied. Subsequent research shows that pivot shift, the giving way of the knee in patients with an ACL tear, is caused by an injury in the ALL ligament.

‪Some of the researchers' conclusions were recently published in the Journal of Anatomy. The Anatomical Society praised the research as "very refreshing" and commended the researchers for reminding the medical world that, despite the emergence of advanced technology, our knowledge of the basic anatomy of the human body is not yet exhaustive.

‪The research questions current medical thinking about serious ACL injuries and could signal a breakthrough in the treatment of patients with serious ACL injuries. Dr Claes and Professor Bellemans are currently working on a surgical technique to correct ALL injuries. Those results will be ready in several years.

‪ACL tears are common among athletes in pivot-heavy sports such as soccer, basketball, skiing and football.

 

Sourcehttp://www.sciencedaily.com/releases/2013/11/131105081352.htm

 

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