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Child Health - Coggle Diagram

- - - - 6 weeks - head control
        6 months - sitting
        1 year - standing, walking
        1.5 years - walk well, running
        2 years - climb stairs, kick ball
        3 years - stand on 1 leg
    - - 6 weeks - fixes and follows object
        6 months - full hand grip, hand to hand transfer
        1 year - mature pincer, object permanence, pointing
        1.5 years - 3 blocks, hand preference, scribbles
        2 years - 7 blocks, circular scribbles
        3 years - draws circles, imitates bridge
    - - 6 weeks - still to sound
        6 months - turns to sound, bables
        1 year - 6-12 words, follows simple instructions
        2 years - 2-word sentences
        3 years - speaks in sentences
    - - 6 weeks - smiles
        6 months - laughs, squeals, puts food in mouth
        1 year - waves, playes peek-a-boo, drinks from cup
        1.5 years - spoon feeding, self-recognition, symbolic play
        2 years - starts toilet training, remove garment
        3 years - parallel play, interactive play, sharing, dressing
  - - - Lumper school of thought
        
        Global construct, perform equally well on different cognitiive taks
        Spearman's G factor - all intellectual activities have 2 factors
        specific - specific task
        general 0 common to all test
      - Splitter school of thought
        
        Intelligence mafde of many specific mental faculties, people have varying levels of intelligence in different areas
        Gardner;s 8 multiple intelligences - specific modalities
        
        Musical-rhythmic and harmonic - musicality
        Visual - spatial
        Verbal-linguistic
        Logical-mathematical - reason
        Bodily kinesthetic - gross and fine motor skills
        Interpersonal - social skills
        Intrapersonal
        Naturalistic
    - - Crystallised - acquired, stored in long-term memory, not affected by nervous system efficiency, increases through mid-adulthood
        Fluid intelligence - abstract reasoning, declines with age
    - - Analytical
        Creative
        Practical
  - - - Biological - basic/primitive reflexes
        Piaget's sensorimotor stage
        Sensory/perceptual changes
    - - Piaget's preoperational stage (symbolic function, intuitive thought)
        Cognitive characteristics - egocentrism, centration, lack of conservation
        Socioemotional development - gender, parents, peers
        Moral feelings, reasoning, behaviour
    - - Piaget's concrete operational stage - achieves conservation
        Development of self, emotional maturation
        Friendships, development of prosocial behaviour (altruism)
        Moral development - Kohlberg's theory (fairness, equal rights), Gilligan's theory (care for others, relationships, gender prespectives)
    - - Brain development - impulsivity, anygdala > prefrontal cortex activitym sexual development
        Piaget's formal operational thought stage (abstract thinking, hypothetical possibilities - reason logically and systematically conclude)
        Social - implications on physicak changes, adolescent sexuality, more idealistic, egocentrism (imaginary audience, personal favour), risk-taking behaviour, dating and romantic relationships, juvenile delinquency, self-disclosure
        Identity
      - Identity development
        
        Erikson's theory - identity vs identity confusion stage
        Havighurst theory - outlines list of developmental tasks
        Maxrcia's theory - diffusion, foreclosure, moratorium, achievement
    - - Substance abuse
        Career/work - Holland's model (6 career-relate personalities - realistic, conventional, enterprising, investifative, artistic, social), super theory of career development
        Attraction - love and friendship (intimacy), loneliness (chronic condition), marriage, family, parenting roles
    - - Biological - ageing brain - reduced neurotransmitters - ACh, dopamine, GABA - adapt by growing new neurons, decreased lateralisation
        Cognitive - selective attention, divided attention, sustained attention (vigilance)
      - Erikson's theory - integrity vs despair, ego transcendence vs preoccupation
        Disengagement theory - gradually withdraw from society to cope effectively with ageing
        Activity theory - more satisfied if active in society
        Socioemotional selectivity theory - deliberately narrow social networks
        Death - Kubler-Ross model - 5 stages of loss
  - - - Sucking - suck anything that touches roof of their mouth
        Rooting - involves newborn infant turning head toward anything that strokes its cheek or mouth
        Palmar grasp
        Stepping - infant attempts to walk when soles of feet touch flat surface while held upright
        Asymmetric tonic neck reflex (ATNR) - when child's head turned to side, ipsilateral arm will straighten while contralateral arm will bend
        Moro - extension of limbs, arms abduct abruptly with palms up and thumbs flexed - later arms adducted, hands clenched into fists, infant cries loudly
        Babinski - dorsiflexion and curling upwards of toes when soles of feet are stroked
    - - Head righting (4-6 months) - head moves to opposite direction - prepares child to sit - vestibular system
        Parachute (7-9 months) - infant held upright and body quickly rotated to face downwards, baby automatically extend arms forward to break fall
- - - - Diarrhoea
        Pneumonia
        Malaria
        Measles
        HIV/AIDS
    - - Normal - 36.1-37.8 (rectal), 36.8 (oral)
        Minimum temperature - 1-6am
        Maximum temperature - 5-7pm
        Circadian rhythm begins to develop after 1 year
        Temperature higher in children, decrease after first year of life
    - - Oesophageal - most accurate but invasive
        Oral cavity
        Tympanic - widely used
        Axillary - less invasive than oral, less reliable in neonates
        Rectal - most accurate not convenient/comfortable
        Strips - crystals applied to mouth/axilla, influenced by external influences
        Electronic - lack of callibration
    - - Immune cells - react to exogenous pyrogens or release endogenous pyrogens (act on hypothalamus), mediators produced by monocytes have direct effects on hypothalamus (PAF, ICAM)
        Pyrogenic cytokines - activate arachidonic acid pathway, GP130-triggering cytokines
        Binding of pyrogenic cytokines - production of neurotransmitters, arachidonic metabolites and ions that act centrally -> elevated PGE2
      - Riley-Day syndrome - autosomal recessive disorder causing ANS dysfunction - affects development and survival of neurons (HSAN-III)
    - - Central - paracetamol - decreases brain COX activity
      - Systemic - aspirin - decreases blood COX activity - reduces amount of circulating endogenous pyrogens (PGE2)
  - - - Head/brain - meningitis, encephalitis
        ENT - mastoiditis
        Respiratory - URTIs, pneumonia, pleural effusion
        Cardiovascular - endocarditis
        Abdominal - abnominal infections, GI infections
        MSK/skin - osteomyelitis, arthritis, integumentary infections (blanching - disappears when pressure applied - cellulitis vs non-blanching - doesn't disappear when pressure applied - non-blanching rash + fever is hallmark of meningococcemia)
        Urinary - UTI
    - - Fever without apparent focus of infection - self-limited viral infections, IV antibiotics recommended if child is unwell
    - - Fever persisting >7 days without identifiable aetiology
  - - - Measles virus
        Transmission - airborne, droplet
        4Ds - 4 day high grade fever
        3 Cs - cough, coryza (cold, fever, sneezing), conjunctivitis
      - Rash pattern
        Exanthem - generalised pruitic red macuolopapular rash
        Enanthem - Koplik spota (small white spots inside cheeks opposite molars)
      - Lab - anti-measles IgM, respiratory RNA isolation, salivary measles IgA
        Treatment - supportive - ibuprofen, MMR vaccine (12 months, 4/5 years)
    - - Group A Strep
        Transmission - droplet
        Strep throat, rash, forchheimer spots
      - Exanthem - diffuse non-painful pruitic blancin scarlatiniform rash (spares face, palms, soles), strawberry tongue (swollen bumpy), pastia lines (confluenct petichae arranged linearly), facial flushing (perioral sparing)
        Desquamination - rash begins to fade after 1 week of onset
        Enanthem - Forchheimer spots - petechiae on soft palate
      - Supprative - peritonsillar abscess, cellulitis
        Non-suppurative - PSGN, rheumatic fever, arthritis
        Lab - rapid antigen detection test
        Treatment - oral penicillin V, IM penicillin G, 1st gen cephalosporin
    - - Rubella virus
        Transmission - droplet, vertical
        Symptom onset 2 weeks after exposure - 3-day maculopapular rash, cervical lymphadenopathy, coryza, swollen glands, sore throat, aches/fatigue
      - Exanthem - generalised pruitic red maculopapular rash (not as bright red as measles - begins on face)
        Enanthem - Forchheimer spots - petichiae on soft palate (fleeting, not diagnostic)
      - Lab - anti-rubella IgM
        Treatment - supportive - ibuprofen, MMR vaccine (12 months, 4/5 years)
      - Congenital rubella syndrome - after intrauterine infection, triad of - sensorineural hearing loss (SNHL), eye abnormalities (retinopathy, cataracts, glaucoma), congenital heart disease (pulmonary artery stenosis, PDA)
    - - Parvovirus B19
        Transmission - droplet, blood
        Presentation - low-grade fever, headache, rash, coryza, self-limiting arthrities (rashes)
      - Exanthem - slapped cheek (pruitic bright red rash especially in cheeks), red lacy rash on rest of body
      - Complications - hydrops fetalis, aplastic crisis
        Lab - anti-parvovirus B19 antibodies
        Treatment - supportive - ibuprofen
    - - HHV-6/7
        Transmission - droplet, vertical
        Sudden high grade fever 2-3 days, then rash
      - Exanthem - non-pruitic red macuolopapular rash - begins on trunk, spreads to limbs and neck
      - Lab - anti-HHV antibodies, viral culture
        Treatment - supportive, ganciclovir/foscarnet
  - - - Exanthem - small itchy blisters
        Enanthem - oral manifestations
        Prevention varicella vaccine
    - - Signs - sudden onset high fever, headache with retro-orbital pain, ache, diffuse erythematous macular rash, mild mucosal bleeding
    - - Diphtheria - Corynebacterium diphtheriae - grey adherent membrane on throat (diphtheritic membrane)
        Pertussis - Bordetella Pertussis - whooping cough
        Poliomyelitis - Poliovirus - flaccid paralysis
        HiB = Haemophilus influenzae - cellulitis
        Pneumococcus - Streptococcus pneumoniae - MOPS (meningitis, otitis media, pneumonia, sinusitis)
    - - Warm CREAM
        
        Persistent high fever >5 days
        Conjunctivities
        Rash - maculopapular erythematous rash - trunk
        Erythema - swelling at palms, soles
        Anlarged - cervical lymphadenopathy
        Mucous - inflammation - dry red strawberry tongue, swollen lips
      - Complication - coronary artery aneurysm
        Treatment - high-dose IVIG (intravenous immunoglobulins), salicylates (aspirin)
- - - - Intraventricular haemorrhage (Grade 1-4)
        Grade 3 and 4 more likely to cause long term issues - post-haemorrhagic ventricular dilatation due to clots forming - impedes circulation and reabsorption of CSF, precedes development of hydrocephalus
      - Retinopathy of Prematurity - visual impairment
        
        Due to exposure to high levels of O2 in NICU become completion of vascularisation
        
        When excess O2 removed, relative ischemia between vascularised and non-vascularised areas - rapid growth of poorly formed fragile vessels, retinal damage - blindness
    - - Bowel becomes necrotic, may perforate
        Loss of mucosal integrity + bacteria
        To,omg pf onset inversely proportional to gestational age
      - Radiological sign - pneumatosis intestinalis - distended, tight abdomen with air in bowel wall
    - - High surface area to volume ratio - skin is thin, fragile, poorly keratinised, lacks subcutaneous fat
    - - Baby's immune system supplemented only by transplacental IgG - amount of IgG transferred increases with gestational age
    - - Pulmonary artery connected to aortic arch
        Left to right shunt
        Normally prostaglandin levels drop after birth, but prostaglandin metabolism poor in premature baby
      - Continuous murmur over upper left sternum
        In baby - systolic/absence of murmur - due to high pulmonary pulse pressure
      - Close using prostaglandin antagonists - NSAIDs
        If blood flow to lung restricted - prostaglandin infusions - alprostadil, dinoprostone (wait for surgery)
    - - Respiratory distress syndrome
        
        Surfactant deficiency, lung hypoplasia
        
        Tachypnoea with increased work of bleeding
        Ground glass appearance, air bronchogram
        
        Treat with steroids in utero
        Surfactant down endotracheal tube - all babies born <28 weeks
      - Chronic lung disease
        
        O2 dependence after 28 days of life or 36 weeks
  - - - Appearance
        Pulse
        Grimace
        Activity
        Respiration
  - - - Umbilical cord
        
        Cord clamping should be delayed by 1 minte from complete delivery - reduce risk of iron deficiency later in life
      - In utero - gaseous exchange via placenta (mother), bypass lungs
        Ex utero - passage to birth canal is hypoxic event - reflex gasping, crying
        Lung fluid reabsorbed by lymphatic and pulmonary system, active chest compression during uterine contractions
        Closure of foramen ovale
    - - Rapid heat loss due to large surface to body mass ratio
    - - Low initial GFR, rises quickly in first 2 weeks
    - - Black tarry stool - meconium - earliest stool of infant, composed of materials ingested in utero
      - Foetal liver is store of glycogen and iron
    - - Glucose levels reach lowest at 1 hour of life, rises by 3 hours (due to fall in insulin), high etone production
        Must establish first feed within 1 hour of birth
      - Mother with gestational diabetes melltus (GDM)
        High foetal insulin levels persist at birth -> further drive hypoglycaemia neonatally
        
        Complications
        
        Miscarriage/stillbirth
        Large for gestational age - difficult delivery
        Prolonged jaundice (polycythemia -> increased haemolysis -> excess billirubin)
        Prematurity - RDS
        Hypertrophic cardiomyopathy
    - - Predominantly HbF in foetus -> changes to HbA
    - - Maternal IgG crosses placenta in 3rd trimester
  - - - DNA methylation
        Histone modification
        Cytoplasmic microRNAs
- - - - Biolodical - Tanner stage II
        Thinking remains concrete but with development of early moral concepts
        Progression of sexual identity development - sexual orientation, homosexual peer interest, body image
        Social - realisation of difference from parents, strong peer identification, exploratory behaviours
    - - Tanner stage 4-5, voice-breaking
        Cognitive - emergence of abstract thinking, conventional morality, development of fervently held ideology, growing verbal abilities
        Social - emotional separation from parents, strong peer identification, heterosexual peer interests, early vocational plans, educational trajectory
    - - Males - completion of taner stage 5
        Cognitive - complex abstract thinking with post-conventional morality, increased impulse control, development of ideology and religion, completion of personal identity
        Social - parents, social autonomy, development of intimate relationships, development of vocational capability
  - - - Biological - delayed puberty, short stature, undernutrition
        Psychosocial - depression/anxiety
      - Adherence - how faithfully person sticks to and participates in treatment plan
        Compliance - following doctor's orders, management more unilateral
    - - Deliberate self harm
        
        Low rate in pre-adolescents
        More common in girls than boys
        
        Acute - substance overdose
        Delayed - self mutilation, banding head against walls, hair pulling, swallowing/inserting objects
      - Eating disorders
        
        Anorexia nervosa - eating restriction - perfectionism
        Bulimia nervosa - binge and purge - impulsiveness
  - - - Early (12-13 years)
        
        Begin discussion, assess adolescent's understanding, start implementing training
        Documentation - provide transition document to parents and adolescent for information
      - Middle (14-15 years)
        
        Introduce concept of confidentiality, adolescent alone, address correspondence to adolescent
        Documentation - develop written plan
      - Late (16-17 years)
        
        Assess readiness of adolescent for transfer - exchange information between services, provide practical information about adult service, overlap clinic/pre-transfer visit to adult service
        Documentation - review and update transition plan
- - - - Differentiation of bone starts at 4 weeks, skeletal development at 3rd trimester
        Bones soft and malleable at birth - fontanelles
      - Ossification - mesenchymal connective tissue becomes cartilate in utero, beocmes bone
      - Achondroplasia - limits growth and lengthening of bones - short stature - mutation in FGFR3 gene (cartilage cannot fully ossify)
    - - Head - 1:4 in neonate vs 1:8 in adult
        Spine - 4, 8, 12 - cervical, lumbar, thoracic
        Ribs - life horizontally undtil 2 years, difficult to breathe thoracically - breathe abdominally using diaphragm until ribs curve
        Limbs - genu varum vs genu valgum
    - - Heart begins to develop 4th week, begins beating weeks 5-7
        Eustachian valve - junction of IVC and right atrium
      - IVC streams of blood
        
        Dorsal - more oxygenated - placenta -> ductus venosus
        Supplies brain and coronary circulations
        
        Ventral - less oxygenated - lower parts of body -> IVC
        Supplies rest of body
    - - Number of alveoli increases until 3 years of age, size increases thereafter, vasculature continues to form until 8 years
        Lung capacity increases between 5 years and puberty
      - Higher laryngeal position (sucking and breathing at same time)
        Smaller airways - increased resistance to airflow
        Less effective thoracic membrane
      - Respiratory rates
        
        Normal
        
        Neonate (<1 year) - 30-40
        
        Infant (1-2 years) - 25-35
        
        Young children (2-5 years) - 25-30
        
        Older children (5-12 years) - 20-25
        
        Adolescents (>12 years) - 15-20
        
        Critical Tachypnoea
        
        Neonate (<1 year) >60
        
        Infant (1-2 years) >50
        
        Young children (2-5 years) >40
        
        Older children (5-12 years) >30
        
        Adolescents (>12 years) >20
      - Rispiratory distress
        
        Children have more compliant rib cages, less compliant lungs - increased breathing rate, shallow breathing
        
        Grunting - forced expiration against closed glottis - hypoxia, atelectasis, pneumonia, pulmonary oedema
    - - Innate immunity
        Adaptive immunity - humoral (antibodies B cells), cellular immunity (T cells)
      - Childhoos infections
        H. influenzae - meningitis, croup, conjunctivitis
        B. pertussis - susceptible as binds to epithelium of large airways, difficult to expel
        Causes whooping cough, vomiting and colour change
  - - - Blocked airways
        Vomit/food/debris in mouth
        Head tilt chin lift manoeuvre - patency of airways
    - - Wheezing - lower airway narrowing, due to viruses/asthmatic response
        Accessory muscle use - chest wall recession, tracheal tug (pulling thyroid cartilage towards sternal notch during inspiration), nasal flaring, head bobbing
        Gunting - exhalation against closed cglottis to prevent lung colapse
        Poor feeding - struggle to feed and breathe simultaneously
        Tachypnoea
    - - Respiratory effectsm skin effectsm mental state, kidneys
        Quiet tachypnoea - without recession - metabolic acidosis with respiratory compensation
    - - Respiratory - abnormal patteerns in comatosed child implies cerebral pathology
      - Cardiac - cushing's response - physiological nervous system response to increae ICP compressing medulla oblongata
        Cushing's triad - hypertension, irregular breathing, sinus bradycardia
    - - Skin - fever, rash, tip/tongue swelling, injuries/trauma
  - - - MDG - child mortality highest in Sub-Saharan Africa
        Lancet - infectious diseases - pneumonia, diarrhoea, malaria
        WHO - biggest non-infectious causes of mortality - preterm birth, birth asphyxia
- - - - Recommendations
        
        Within 1 h - early initiation
        First 6 months - exclusive breastfeeding - reduce risk of infections
        6 months - non-exclusive breastfeeding
      - Formula in addition to breastmilk - very low birth weight, premature
        Maternal HIV - exclusive breastfeeding in first 6 months reduces risk of HIB, prolonged breastfeeding > 6 months - increases rate of HIV
        
        mixed feeding has highest risk of HIV
    - - Nutritional interventions
        
        Vitamin A supplementation
        Iron supplementation and deworming - parasites
        Zinc supplementation - diarrhoea management
      - Obesity
        
        Metabolic syndrome - 2/3 - diabetes, hypertension, dyslipidemia
        Complication - maintenence of obesity into childhood
  - - - Marasmus - protein-energy malnutrition
        
        Severe deficiency of all nutrients - inadequate calorie intake Better prognosis
        Mid-upper arm circumference <11.5 cm
        Low weight for height (wasting) - z-score <=-3
        
        Voracious appetite, absent subcutaneous fat, fatty liver uncommon
      - Kwashiorkor - bilateral piting oedema
        
        Severe protein deficiency, normal calorie intake
        Worse Prognosis
        
        Sparse hair, poor appetite, fatty liver common
      - Management - delay introduction of iron
        
        Iron must be transported in blood while complexed to transferrin as it is highly reactive, sequestration limits microbial replication
        These children have normal albumin levels, very low transferrin levels (takes time to improve)
    - - Environmental enteropathy
        
        Chronic T cell-mediated inflammatory enteropathy - driven by environmental factors
        
        Histology - indistinguishable from other forms of IBD
        
        Pathogenesis - faecal ingestion - bacterial ingestion overwhelms gastric barrier - enteric T cell stimulation
        Reduced small intestinal surface area - reduced nutrient absorption
        Increased intestinal permeability - microbial translocation
        
        Management - transplantation of faecal material via nasogastric tube - for C. difficile infection
        Enteric vaccines
    - - Vitamin A
        
        Downregulation of monocyte production of TNFa and IL-6
        
        Eyes - night blindness, xerophthalmia (dryness of conjunctiva and cornea with inflammation and ridge formation)
        Increased risk of infectious diseases
      - Zinc
        
        Diarrhoea
        Acrodermatitis enteropathica - eczematous lesions around mouth and anus, chronic diarrhoea
      - Anaemia
        
        Iron deficiency
        Anaemia of chronic disease
        Malaria
        
        Management - iron supplementation (causes black stools, change in bowel habits)
        Hepcidin rapid diagnostic test
        
        hepcidin is regulator of iron metabolism to reduce serum iron levels
        Serum hepcidin predicts extent of iron incorporation (low in true iron deficiency anaemia, high in anaemia secondary to infection)
      - Goitre - iodine deficiency
- - - - Growth hormone
        
        Increased mineralisation of bone
        Increased transport of amino acids
        Increased fatty acid breakdown
        Promotes hepatic gluconeogenesis
        
        Increased release - sleep, sex hormones
        Decreased release - stress, cortisol, negative feedback from GH and IGF-1
      - IGF-1
        
        Stimulates bone growth
        Stimulates muscle cells to synthesise protein
        Increases glucose uptake into cells
    - - Bone age - more immature bones - more potential
        Determined by bone growth at epiphyseal growth plates - non-dominant hand
        Normal bone age in short child suggests familial short stature - abnormal if bone age more than 2SD below child's age
  - - - Height falling through centiles
      - Short and undeweight - undernutrition, chronic illness/disease
        Relatively overweight - endocrine
        Long legs compared to back - constitutional delay of puberty - treat with testosterone/oestrogen
        Short and underweight with delayed puberty - psychosocial deprivation - catch-up growth noted if child moved to more nurturing environment
      - Short - endocrine
        Lightweight - nutritional
        equal - constitutional/familial/psychosocial
    - - Weight gain less than height - inadequate nutritional intake
      - Catchup/catchdown growth
    - - Height <2nd centile, staying on centile
      - Familial - within range for mid-parental height
        Consitutional delay of growth and puberty - will reach normal adult height but delayed bone age
        IUGR - catchup growth but not enough to compensate
        Musculoskeletal disorders (ratio sitting height to subischial leg length
      - Chromosomal disorders
        
        Down syndrome - diagnosed at birth
        Turner syndrome - short females - hypoplastic nails from birth
        Noonan syndrome - webbed neck, flat nose bridge, ptosis
        Russell-silver syndrome - triangular shaped face, clinodactyly (curved 5th finger)
        Prader-willi syndrome - hypotonia, excess weight gain, developmental delay
    - - Proportionately tall at birth
        
        Beckwith-Wiedemann syndrome - macroglossia, umbilical hernia, omphalocele, neonatal hypoglycemia
        Maternal diabetes
      - Long-legged tall stature
        
        Marfan syndrome
        Klinefelter syndrome
        Homocystinuria - high arched feet, genu valgum, eye disease, learning disability
      - Large head
        
        Sotos syndrome - large, long, narrow face, learning difficulties
- - - - Adrenarche - development of zona reticularis of adrenal cortex
        Congenital adrenal hyperplasia (CAH) - disconcordant growth, axillary/pubic hair growth before thelarche
    - - LH - acts on specialised interstitial cells of gonads - androgens
        FSH - acts on follicular compartment - oestrogen, inhibin, gametes
      - Foetal life
        1st trimester - establishment of HPG axis
        2nd trimester - establishment of penile size and inguinal-scrital phase of testicular descent
        2nd half - suppressed by high oestrogen levels
      - Neonatal life
        Beginning - functions at pubertal level
        End - HPG axis under gradual CNS restraint
      - Childhood - HPG axis relatively dormant
        Adulthood - increasing activity late prepubertal (recession of CNS restraint)
    - - Selective GH resistance
        
        small testes, micropenis, poor breast and sexual hair development, absence of pubertal growth spurt
      - Inhibitory - GABA, opioid
        Excitatory - glutamate, kisspeptin
    - - LH - Leydig cells of testes, secrete testosterone
        FSH - Sertoli cells of testes - gametogenesis and gonadal growth
        LH - Theca cells of ovaries to form precursors of oestradiol
        FSH - Granulosa cells of ovaries stimulate gametogenesis and gonadal growth
    - - Prepubertal
        
        development of gonads (breast, testicular enlargement stage 2)
        
        ongoing pubertal development
        
        nearly complete
        
        complete and adult-like development
      - Orchidometer
      - Pubertal sequence
        
        Males
        
        9-14 years, 4ml testes
        
        penile and scrotal enlargement
        
        pubarche
        
        pubertal growth spurt and spermarche
        
        further masculinisation
        
        Females
        
        8-13 years, thelarche
        
        pubarche and axillary hair growth
        
        pubertal growth spurt and fat redistribution
        
        manarche
      - Normal variations
        
        Asymmetric breast/testicular development
        Gynaecomastia
  - - - Male
        
        Delayed - physiological - absence of testicular development or testicular volume <4ml in boys >14 years
        Precocious - pathological - onset of testicular devopment or testicular volume 4ml in boys <9 years
      - Female
        
        Delayed - pathological - absence of breast development in girls >13 years
        Precocious - physiological - onset of breast development in girls <8 years
    - - Constitutional
        
        Familial, more common in male
        Idiopathic deay on onset of HPG axis activation - delayed skeletal maturity, catch-up growth
      - Pathological
        
        Delayed hypothalamic GnRH secretion - chronic disease, malnutrition, excessive physical exercise, steroid therapy, hypothyroidism
      - Pubertal failure
        
        Central
        
        Tumours adjacent to HPG axis, irradiation, trauma, GnRH deficiency, Cushing's
        
        Peripheral - ovarian failure
        
        Gonadal dysgenesis - Turner's
        Steroid hormone enzyme deficiencies
        Ovarian damage
        Toxic damage - galactossaemia, iron overload (thalassaemia)
        
        Peripheral - testicular failure
        
        Gonadal dysgenesis - Klinefelter's
        Cryptochidism (noonan, prader-willi)
        Testicular damage
        Toxic damage
    - - Gonadotrophin-dependent - central
        
        Early activation of HPG axis - likely non-pathological and familial - females
        Pathological causes - CNS anomalies (hydrocephalus, tumours), acquired (chemo, surgery)
      - Gonadotrophin-dependent - peripheral
        
        Increased testosterone/oestrogen from abnormal source - suppress HPG, low LH/FSH
        Likely pathological - adrenal disorders, hyperfunctioning ovarian/testicular tumours