You are an experienced medical professor guiding me, a medical student preparing to study Anki flashcards focused on clinical reasoning and practical applications of medicine. Before I attempt the flashcards, please provide a comprehensive study session on the key topics. For each topic, offer clear and concise explanations, relevant clinical examples, and insights into how it applies to clinical decision-making. Then, challenge me with related questions to stimulate critical thinking (and provide the answers afterward). Be instructional yet accessible, balancing depth with conciseness.
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By what age does an infant develop stranger anxiety?   ::9 months	"Stranger anxiety starts around 6 months, but peaks at 9 months, and resolves spontaneously by 2 years of age   Developmental MilestonesAgeGross MotorFine MotorLanguageSocial/Cognitive2 months• Lifts head/chest in prone position• Hands unfisted 50% of the time• Alerts to voice/sound • Makes noises• Social smile • Recognizes parents • Eyes track past midline4 months• Head control • Props up on forearms• Brings hands to midline/mouth • Holds objects if placed in palm• Responds to voice • Coos (vowel sounds)• Enjoys looking around (at hands, at objects)6 months• Sits momentarily propped on hands (tripod position) • Rolls over• Reaches for toys • Puts objects in mouth• Vocalizes (squeals, blows raspberries)• Laughs • Recognizes familiar faces • Stranger anxiety 9 months• Sits independently• Raking grasp • Transfers objects hand to hand• Babbles (consonant sounds) • Responds to name• Separation anxiety1 year• Pulls to stand • Cruises• Pincer grasp• Says ""mama"" or ""dada"" • Waves ""bye"" • Understands ""no""• Plays ""pat-a-cake"" • Looks for hidden object15 months• Takes a few steps independently• Stacks 2 blocks• Says 1 or 2 words (plus ""'mama"" & ""dada"")• Follows 1-step command with gesture • Points to get something • Shows affection18 months• Walks easily • Climbs on/off furniture• Scribbles • Feeds with fingers• Says ≥ 3 words (plus ""mama"" & ""dada"")• Follows 1-step command without gesture • Imitates caregiver2 years• Runs • Kicks ball • Walks up stairs• Uses spoon• Says 2-word phrases• Knows 2 body parts • Parallel play30 months• Jumps• Removes clothes • Turns pages• Says ≥ 50 words• Follows 2-step command • Identifies 1 color correctly3 years• Walks up stairs alternating feet • Rides tricycle• Dresses with help • Uses fork • Copies circle• Says ≥ 3-word sentences • Speech 75% intelligible• Knows age/sex • Cooperative play4 years• Catches large ball• Tripod pencil grasp• Says ≥ 4 word sentences • Names colors• Imaginative play5 years• Hops on 1 foot• Buttons clothes • Writes some letters• Speech 100% intelligible • Counts to 10 • Speaks in full sentences• Understands rules and taking turns"
By what age does an infant develop separation anxiety?   ::9 months	- This is an overwhelming fear of separation from home or attachment figure ≥ 4 weeks; have already developed a social smile and stranger anxiety   - Normal behavior up to age 3-4
By age 12 months, an infant's weight should ::triple and height should increase by ::50%	Weight should double by age 4 months   Photo Credit: CDC, Public Domain
What gross motor developmental milestone(s) are expected in a 2 month old?   ::Lift head in prone position	
What language developmental milestone(s) are expected in a 2 month old?   ::Makes noises, alert to voice/stimuli	
What social developmental milestone(s) are expected in a 2 month old?   ::Social smile, recognizes parents	
What gross motor developmental milestone(s) are expected in a 4 month old?   ::Head control, props up on forearms	
What language developmental milestone(s) are expected in a 4 month old?   ::Turns to voice, coos (vowel sounds)	
What gross motor developmental milestone(s) are expected in a 6 month old?   ::Sits momentarily propped on hands	"Sits at Six
What fine motor developmental milestone(s) are expected in a 6 month old?   ::Reaches for toys, puts objects in mouth	
What language developmental milestone(s) are expected in a 6 month old?   ::Vocalizes	
What gross motor developmental milestone(s) are expected in a 9 month old?   ::Sits independently	
What fine motor developmental milestone(s) are expected in a 9 month old?   ::Raking grasp, holds bottle or cup	
"What language developmental milestone(s) are expected in a 1 year old?   ::Says ""dada"", ""mama"""	
What gross motor developmental milestone(s) are expected in a 12 month old?   ::Pulls to stand, cruises	
"What language developmental milestone(s) are expected in a 15 month old?   ::Says first words aside from ""mama"" and ""dada"""	"This card used to say 12 months, but AMBOSS + UWorld confirm it's 15 months (Dec 2023)     
What gross motor developmental milestone(s) are expected in an 18 month old?   ::Walks easily, climbs on and off chair	"Eighteen months = Easily walks     
What fine motor developmental milestone(s) are expected in an 18 month old?   Feeds with ::fingers, scribbles	"
"What language developmental milestone(s) are expected in an 18 month old?   Says ::≥ 3 words plus ""mama"" and ""dada,"" identifies ≥ 1 body parts"	"Used to say 10-25 word vocabulary, but AMBOSS now lists this milestone as 3 or more words in addition to dada and mama (July 2023) based on the 2022 CDC milestones update      
What gross motor developmental milestone(s) are expected in a 2 year old?   ::Kicks a ball, runs, walks up stairs	"
What fine motor developmental milestone(s) are expected in a 2 year old?   - Builds a tower with ::6 cubes - Copies a(n) ::line	"
What language developmental milestone(s) are expected in a 2 year old?   ::2-word phrases	"This card used to say ≥ 50-word vocabulary, but per UWorld, this is expected of a 2.5-year-old (30 months)     
What social developmental milestone(s) are expected in a 2 year old?   Begins ::parallel play, follow 2-step commands	"
What gross motor developmental milestone(s) are expected in a 3 year old?   ::Rides tricycle, walks up/down stairs with alternating feet	"
What fine motor developmental milestone(s) are expected in a 3 year old?   Copies a(n) ::circle, uses ::utensils	"3 years old = 3 utensils (fork, spoon, and knife)     
What language developmental milestone(s) are expected in a 3 year old?   ::3-word sentences, speech 75% intelligible	"
What social developmental milestone(s) are expected in a 3 year old?   Begins ::play with other children, knows age/gender	"Cooperative play by 4 years old    
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