Figures

<span id="v91502239" class="anchor" ></span><div class="para" > <p >The vertical lines represent the frequencies that are tested from 125 to 8000 Hz. The horizontal lines record the threshold at which the patient states that the sound is heard.</p></div><span id="v91502240" class="anchor" ></span><div class="para" > <p >Normal thresholds are 0 dB <span class='symbol' >+</span>/<span class='symbol' >−</span> 10 dB. Patients with a hearing threshold 20 dB or lower are considered to have normal hearing. The greater the dB, the louder is the sound and the worse the hearing. </p></div><span id="v91502241" class="anchor" ></span><div class="para" > <p >"O" is the standard symbol for air conduction of the right ear; "X" is the standard symbol for air conduction for the left ear. The "<span class='symbol' ><</span>" is the standard symbol for unmasked bone conduction for the right ear ("<span class='symbol' >></span>" is the standard symbol for unmasked bone conduction of the left ear).</p></div><span id="v91502242" class="anchor" ></span><div class="para" > <p >The reason why both masked and unmasked measures are needed is to make sure one ear is not hearing the sound presented to the other ear (one ear is "masked" so it does not hear the sound presented to the other ear, giving a false value). However, if air conduction is symmetric, only unilateral unmasked bone conduction need be done.</p></div><span id="v91502243" class="anchor" ></span><div class="para" > <p >Image courtesy of Mickie Hamiter, MD.</p></div>

Audiogram of Right Ear in a Patient with Normal Hearing

Paranasal sinuses

<span id="v25241901" class="anchor" ></span><div class="para" > <p >When relaxed, the vocal cords normally form a V-shaped opening that allows air to pass freely through to the trachea. The cords open during inspiration and close during swallowing or speech. When a mirror is held in the back of a patient’s mouth, the vocal cords can often be seen and checked for disorders, such as contact ulcers, polyps, nodules, paralysis, and cancer. Paralysis may affect one (unilateral) or both vocal cords (bilateral—not shown).</p></div>

Laryngeal disorders

How People Sense Flavors

Inside the Ear

<span id="v37716170" class="anchor" ></span><div class="para" > <p >The maneuver is done by following the clockwise order of the red arrows below.</p></div>

Epley maneuver: A Simple Treatment for a Common Cause of Vertigo

Algorithm for use of antibiotics in acute sinusitis

Tympanic Membrane of Right Ear (A); Tympanic Cavity with Tympanic Membrane Removed (B)

<span id="v56234802" class="anchor" ></span><div class="para" > <p >Serum potassium is in mEq/L and mmol/L.</p></div>

ECG patterns in hypokalemia

Synthesis of Thyroid Hormones

<span id="v56234793" class="anchor" ></span><div class="para" > <p >Serum potassium is in mEq/L and mmol/L.</p></div>

ECG patterns in hyperkalemia

The pituitary and its target organs

<span id="v56218276" class="anchor" ></span><div class="para" > <p >A 10-g monofilament esthesiometer is touched to specific sites on each foot and is pushed until it bends. This test provides a constant, reproducible pressure stimulus (usually a 10-g force), which can be used to monitor change in sensation over time. Both feet are tested, and presence (<span class='symbol' >+</span>) or absence (<span class='symbol' >−</span>) of sensation at each site is recorded.</p></div>

Diabetic Foot Screening

<span id="v56223075" class="anchor" ></span><div class="para" > <p >Total body water <span class='symbol' >=</span> 70 kg <span class='symbol' >×</span> 0.60 <span class='symbol' >=</span> 42 L (280 mOsm/kg [280 mmol/kg]).</p></div>

Fluid compartments in an average 70-kg man

Preseptal and Orbital Cellulitis

<span id="v8423158" class="anchor" ></span><div class="para" > <p >(A) Emmetropia; (B) myopia; (C) hyperopia; (D) astigmatism.</p></div>

Errors of Refraction

<span id="v42290059" class="anchor" ></span><div class="para" > <p >The zonules of Zinn keep the lens suspended, and the muscles of the ciliary body focus the lens. The ciliary body also secretes aqueous humor, which fills the anterior and posterior chambers, passes through the pupil into the anterior chamber, and drains primarily via the Schlemm canal. The iris regulates the amount of light entering the eye by adjusting the size of its central opening, the pupil. Visual images are focused on the retina. The conjunctiva covers the eyeball and lines the upper and lower eyelids; it ends at the limbus. The cornea is covered with epithelium that is more sensitive than and differs from the conjunctival epithelium.</p></div>

Cross Section of the Eye

Anatomy of the Lacrimal System

<span id="v56123338" class="anchor" ></span><div class="para" > <p >Aqueous humor is produced in the ciliary body behind the iris (in the posterior chamber), passes into the front of the eye (anterior chamber), and then exits through the drainage canals or the uveoscleral pathway (black arrows).</p></div>

Aqueous Humor Production and Flow

<span id="v6656229" class="anchor" ></span><div class="para" > <p >Pinguecula and pterygium are benign conjunctival growths that can result from chronic actinic irritation. </p></div><span id="6b5b4811-3ddb-4d3d-80f4-75fd761855d1" class="anchor" ></span><div class="para" > <p >Pinguecula (left) is accumulation of conjunctival tissue at the nasal or temporal junction of the sclera and cornea.</p></div><span id="c02ec948-9d47-40de-a560-55a93b837a80" class="anchor" ></span><div class="para" > <p >Pterygium (right) is conjunctival tissue that becomes vascularized, invades the cornea, and may decrease vision due to obstruction or induced astigmatism.</p></div>

Pinguecula and Pterygium

<span id="v56235905" class="anchor" ></span><div class="para" > <p >With retrochiasmal lesions, visual field defects are on the same side (homonymous) and tend to become more symmetric (congruous) with more posterior lesions, as shown with the occipital lesion in #4.</p></div>

Higher Visual Pathways—Lesion Sites and Corresponding Visual Field Defects

Where Tears Come From

Deer Ticks

<span id="v27414838" class="anchor" ></span><div class="para" > <p >Size and morphology vary depending on species and maturity.</p></div>

Representative Structure of a Tapeworm, Based on <i >Taenia solium</i>

Representative Structure of a Tapeworm, Based on <i>Taenia solium</i>

<span id="v56241625" class="anchor" ></span><div class="para" > <p >HIV attaches to and penetrates host T cells, then releases HIV RNA and enzymes into the host cell. HIV reverse transcriptase copies viral RNA as proviral DNA. Proviral DNA enters the host cell’s nucleus, and HIV integrase facilitates the proviral DNA’s integration into the host’s DNA. The host cell then produces HIV RNA and HIV proteins. HIV proteins are assembled into HIV virions and bud from the cell surface. HIV protease cleaves viral proteins, converting the immature virion to a mature, infectious virus.</p></div>

Simplified HIV Life Cycle

<span id="v55923258" class="anchor" ></span><div class="para" > <p >Humans may develop intestinal infection with adult worms after ingestion of contaminated pork or may develop cysticercosis after ingestion of eggs (making humans intermediate hosts).</p></div><div class="list"> <ul data-mmanualobjecttype="List" class="nobulleted"><li class="topic__listitem" ><span id="v55923261" class="anchor" ></span><div class="para" > <p >1. Humans ingest raw or undercooked pork containing cysticerci (larvae).</p></div></li><li class="topic__listitem" ><span id="v55923263" class="anchor" ></span><div class="para" > <p >2. After ingestion, cysts evaginate, attach to the small intestine by their scolex, and mature into adult worms in about 2 months.</p></div></li><li class="topic__listitem" ><span id="v55923265" class="anchor" ></span><div class="para" > <p >3. Adult tapeworms produce proglottids, which become gravid; they detach from the tapeworm and migrate to the anus. </p></div></li><li class="topic__listitem" ><span id="v55923267" class="anchor" ></span><div class="para" > <p >4. Detached proglottids, eggs, or both are passed from the definitive host (human) in feces.</p></div></li><li class="topic__listitem" ><span id="v55923269" class="anchor" ></span><div class="para" > <p >5. Pigs or humans become infected by ingesting embryonated eggs or gravid proglottids (eg, in fecally contaminated food). Autoinfection may occur in humans if proglottids pass from the intestine to the stomach via reverse peristalsis.</p></div></li><li class="topic__listitem" ><span id="v55923271" class="anchor" ></span><div class="para" > <p >6. After eggs are ingested, they hatch in the intestine and release oncospheres, which penetrate the intestinal wall.</p></div></li><li class="topic__listitem" ><span id="v55923273" class="anchor" ></span><div class="para" > <p >7. Oncospheres travel through the bloodstream to striated muscles and to the brain, liver, and other organs, where they develop into cysticerci. Cysticercosis can result.</p></div></li></ul></div>

<i >Taenia solium</i> Life Cycle

<i>Taenia solium</i> Life Cycle

<span id="v56216531" class="anchor" ></span><div class="para" > <p >The only known definitive hosts for <i >T. gondii</i> are members of family Felidae (domestic cats and their relatives).</p></div><div class="list"> <ul data-mmanualobjecttype="List" class="nobulleted"><li class="topic__listitem" ><span id="v56216535" class="anchor" ></span><div class="para" > <p >1a. Oocysts are shed in the cat’s feces. Large numbers are shed, but usually only for 1–2 weeks. Oocysts take 1–5 days to sporulate and become infective.</p></div></li><li class="topic__listitem" ><span id="v56216537" class="anchor" ></span><div class="para" > <p >1b. Cats become reinfected by ingesting sporulated oocysts.</p></div></li><li class="topic__listitem" ><span id="v56216539" class="anchor" ></span><div class="para" > <p >2. Soil, water, plant material, or cat litter becomes contaminated with oocysts. Intermediate hosts in nature (eg, birds, rodents, wild game, animals bred for human consumption) become infected after ingesting infective materials.</p></div></li><li class="topic__listitem" ><span id="v56216541" class="anchor" ></span><div class="para" > <p >3. Oocysts develop into tachyzoites shortly after ingestion.</p></div></li><li class="topic__listitem" ><span id="v56216543" class="anchor" ></span><div class="para" > <p >4. Tachyzoites spread throughout the body and form tissue cysts in neural, eye, and muscle tissue.</p></div></li><li class="topic__listitem" ><span id="v56216545" class="anchor" ></span><div class="para" > <p >5. Cats become infected after consuming intermediate hosts containing tissue cysts.</p></div></li><li class="topic__listitem" ><span id="v56216547" class="anchor" ></span><div class="para" > <p >6a. Humans can become infected by ingesting undercooked meat containing tissue cysts.</p></div></li><li class="topic__listitem" ><span id="v56216549" class="anchor" ></span><div class="para" > <p >6b. Humans can become infected by ingesting food or water contaminated with cat feces or other feces-contaminated materials (eg, soil) or contact with a pet cat’s litter.</p></div></li><li class="topic__listitem" ><span id="v56216551" class="anchor" ></span><div class="para" > <p >7. Rarely, human infection results from blood transfusion or organ transplantation.</p></div></li><li class="topic__listitem" ><span id="v56216553" class="anchor" ></span><div class="para" > <p >8. Rarely, transplacental transmission from mother to fetus occurs.</p></div></li><li class="topic__listitem" ><span id="v56216555" class="anchor" ></span><div class="para" > <p >9. In the human host, parasites form tissue cysts, most commonly in skeletal muscle, myocardium, the brain, and the eyes; these cysts may remain throughout the life of the host and can reactivate if the host becomes immunocompromised.</p></div></li></ul></div>

<i >Toxoplasma gondii</i> life cycle

<i>Toxoplasma gondii</i> life cycle

Time vs Concentration of a Single Dose of a Theoretical Antibiotic

<span id="v55249812" class="anchor" ></span><div class="para" > <p >The alpha (<span class='symbol' >α</span>) and beta (<span class='symbol' >β</span>) chains of the T-cell receptor (TCR) bind to antigen (Ag)–major histocompatibility complex (MHC) on an antigen-presenting cell (APC), and CD4 or CD8 interacts with the MHC. Both actions stimulate the T cell (first signal) through the accessory CD3 chains. However, without a second (coactivation) signal, the T cell is anergic or tolerant.</p></div><span id="v55249813" class="anchor" ></span><div class="para" > <p >The TCR is structurally homologous to the B-cell receptor; the <span class='symbol' >α</span> and <span class='symbol' >β</span> (or gamma [<span class='symbol' >γ</span>] and delta [<span class='symbol' >δ</span>]) chains have constant (C) and variable (V) regions. (1) <span class='symbol' >=</span> first signal; (2) <span class='symbol' >=</span> second signal.</p></div>

Two-Signal Model for T-Cell Activation

<span id="v55565468" class="anchor" ></span><div class="para" > <p >The classical, lectin, and alternative pathways converge into a final common pathway when C3 convertase (C3 con) cleaves C3 into C3a and C3b. Ab <span class='symbol' >=</span> antibody; Ag <span class='symbol' >=</span>antigen; C1-INH <span class='symbol' >=</span><span class="genericDrug" data-showrollover="false">C1 inhibitor</span>; MAC <span class='symbol' >=</span> membrane attack complex; MASP <span class='symbol' >=</span> MBL-associated serine protease; MBL <span class='symbol' >=</span> mannose-binding lectin. Overbar indicates activation. </p></div>

Complement Activation Pathways

<span id="v55565459" class="anchor" ></span><div class="para" > <p >The B-cell receptor consists of an Ig molecule anchored to the cell’s surface. CH <span class='symbol' >=</span> heavy chain constant region; CL <span class='symbol' >=</span> light chain constant region; Fab <span class='symbol' >=</span> antigen-binding fragment; Fc <span class='symbol' >=</span> crystallizable fragment; Ig = immunoglobulin; L-kappa (κ) or lambda (λ) = 2 types of light chains; VH <span class='symbol' >=</span> heavy chain variable region; VL <span class='symbol' >=</span> light chain variable region.</p></div>

B-cell Receptor

<span id="v56121436" class="anchor" ></span><div class="para" > <p >Typically, the anterior two thirds of each testis is covered by the tunica vaginalis, where fluids can accumulate. The tunica vaginalis attaches to the posterolateral surface of the testes and limits their movement within the scrotum. If the fixation is too high (anterior and cephalad), the testes can move more freely and torsion is more likely. A: Fixation is normal. B: Fixation is too high, allowing the testis to rotate transversely and resulting in torsion.</p></div>

Abnormal testicular fixation leading to torsion

<span id="v56119504" class="anchor" ></span><div class="para" > <p >Bars indicate normal ranges. No mean is available for change in habitus.</p></div>

Puberty—When Male Sexual Characteristics Develop

Electron Microscopic Features in Immunologic Glomerular Disorders

Suggested Evaluation for Malabsorption

<span id="v56119917" class="anchor" ></span><div class="para" > <p >* Total <span class="genericDrug" data-showrollover="false">testosterone</span> has lower sensitivity for hypogonadism in men aged > 50 years. If the test for free and weakly bound <span class="genericDrug" data-showrollover="false">testosterone</span> is available, levels are measured. If not, levels are calculated.</p></div><span id="v56119918" class="anchor" ></span><div class="para" > <p >† Recommended by some physicians.</p></div><span id="v56119919" class="anchor" ></span><div class="para" > <p >CT <span class='symbol' >=</span> computed tomography; Fe <span class='symbol' >=</span> iron; FSH <span class='symbol' >=</span> follicle-stimulating hormone; GnRH <span class='symbol' >=</span> gonadotropin-releasing hormone; LH <span class='symbol' >=</span> luteinizing hormone; MRI <span class='symbol' >=</span> magnetic resonance imaging.</p></div>

Laboratory Evaluation of Male Hypogonadism

<span id="v56231605" class="anchor" ></span><div class="para" > <p >The CNS inhibits voiding until the appropriate time and coordinates and facilitates input from the lower urinary tract to start and complete voiding. The sympathetic system contracts the smooth muscle sphincter. The parasympathetic nervous system contracts the bladder detrusor muscle through cholinergic fibers. The somatic nervous system contracts the striated muscle sphincter through cholinergic fibers from the pudendal nerve. (Adapted from DuBeau CE, Resnick NM with the Massachusetts Department of Health EDUCATE project collaborators: <i >Urinary Incontinence in the Older Adult: An Annotated Speaker/Teacher Kit,</i> 1993; used with permission of the authors.)</p></div>

Normal Micturition: Coordinated Bladder Contraction and Urethral Sphincter Relaxation

<span id="v55883518" class="anchor" ></span><div class="para" > <p >How genotype is translated into phenotype depends on penetrance and expressivity.</p></div><span id="v55883519" class="anchor" ></span><div class="para" > <p >Penetrance refers to whether the gene is expressed or not. That is, it refers to how many people with the gene have the trait associated with the gene. Penetrance may be complete (100%) or incomplete (eg, 50% when only half the people have the trait). </p></div><span id="v55883521" class="anchor" ></span><div class="para" > <p >Expressivity determines how much the trait affects or how many features of the trait appear in the person. It ranges from complete to minimal, or it may not be present. Various factors, including genetic makeup, exposure to harmful substances, other environmental influences, and age, can affect expressivity.</p></div><span id="v55883522" class="anchor" ></span><div class="para" > <p >Both penetrance and expressivity can vary: People with the gene may or may not have the trait and, in people with the trait, how the trait is expressed can vary.</p></div>

Penetrance and expressivity

<span id="v55354634" class="anchor" ></span><div class="para" > <p >DNA (deoxyribonucleic acid) is the cell’s genetic material, contained in chromosomes within the cell nucleus and mitochondria. </p></div><span id="v55354635" class="anchor" ></span><div class="para" > <p >Except for certain cells (for example, sperm and egg cells and red blood cells), the cell nucleus contains 23 pairs of chromosomes. A chromosome contains many genes. A gene is a segment of DNA that provides the code to construct a protein or RNA molecule. </p></div><span id="v55354636" class="anchor" ></span><div class="para" > <p >The DNA molecule is a long, coiled double helix that resembles a spiral staircase. In it, two strands, composed of sugar (deoxyribose) and phosphate molecules, are connected by pairs of four molecules called bases, which form the steps of the staircase. In the steps, adenine is paired with thymine and guanine is paired with cytosine. Each pair of bases is held together by a hydrogen bond. A gene consists of a sequence of bases. Sequences of three bases code for an amino acid (amino acids are the building blocks of proteins) or other information.</p></div>

Structure of DNA

Location of Abdominal Pain and Possible Causes

<span id="v755069" class="anchor" ></span><div class="para" > <p >A hiatus hernia is an abnormal bulging of a portion of the stomach through the diaphragm.</p></div>

Understanding Hiatus Hernia

Volar Splint

<span id="v56117884" class="anchor" ></span><div class="para" > <p >The patient bends at the waist with the affected arm hanging down perpendicular to the floor. The arm and shoulder should be relaxed, and knees bent. Patients should</p></div><div class="list"> <ul data-mmanualobjecttype="List" class="bulleted"><li class="topic__listitem" ><span id="v56117887" class="anchor" ></span><div class="para" > <p >Slowly swing their arm from side to side, from back to front, and in circles clockwise and counterclockwise</p></div></li><li class="topic__listitem" ><span id="v56117889" class="anchor" ></span><div class="para" > <p >Shift their weight from foot to foot in the same direction that their arm swings</p></div></li><li class="topic__listitem" ><span id="v56117891" class="anchor" ></span><div class="para" > <p >Gradually increase the arc as tolerated</p></div></li></ul></div><span id="v56117892" class="anchor" ></span><div class="para" > <p >These exercises should cause only minimal pain. Patients should do each exercise 2 times per set and do several sets per day. Patients should gradually increase the duration of the exercises.</p></div>

Codman Exercises

Class B Clavicular Fractures

<span id="v56117402" class="anchor" ></span><div class="para" > <p >The practitioner adducts the dislocated arm with the elbow held at 90°. The arm is then externally rotated slowly (eg, over 5 to 10 min) to allow time for muscle spasms to resolve. Reduction commonly occurs at 70 to 110° of external rotation.</p></div>

Hennepin technique for reducing anterior shoulder dislocations

<span id="v56118134" class="anchor" ></span><div class="para" > <p >Fracture of the 2nd metatarsal base may disrupt one or more of the tarsometatarsal joints. In this figure, the 2nd metatarsal fracture displaces the 3rd through 5th metatarsals laterally.</p></div>

Fracture of the 2nd Metatarsal Base With Tarsometatarsal Joint Dislocation

<span id="v56117699" class="anchor" ></span><div class="para" > <p ><b >Transverse</b> fractures are perpendicular to the long axis of a bone. </p></div><span id="v56117700" class="anchor" ></span><div class="para" > <p ><b >Oblique</b> fractures occur at an angle. </p></div><span id="v56117701" class="anchor" ></span><div class="para" > <p ><b >Spiral</b> fractures result from a rotatory mechanism; on radiographs, they are differentiated from oblique fractures by a component parallel to the long axis of bone in at least 1 view. </p></div><span id="v56117702" class="anchor" ></span><div class="para" > <p ><b >Comminuted</b> fractures have <span class='symbol' >></span> 2 bone fragments. Comminuted fractures include segmental fractures (2 separate breaks in a bone). </p></div><span id="v56117703" class="anchor" ></span><div class="para" > <p ><b >Avulsion</b> fractures are caused by a tendon dislodging a bone fragment. </p></div><span id="v56117704" class="anchor" ></span><div class="para" > <p >In <b >impacted</b> fractures, bone fragments are driven into each other, shortening the bone; these fractures may be visible as a focal abnormal density in trabeculae or irregularities in bone cortex. </p></div><span id="v56117705" class="anchor" ></span><div class="para" > <p ><b >Torus</b> fractures (buckling of the bone cortex) and <b >greenstick</b> fractures (cracks in only 1 side of the cortex) are childhood fractures.</p></div>

Common Types of Fracture Lines

<span id="v56117380" class="anchor" ></span><div class="para" > <p >The patient lies on a stretcher, and its wheels are locked. One practitioner pulls on a folded sheet wrapped around the patient’s chest. Another practitioner pulls the affected limb down and laterally 45<span class='symbol' >°</span>. After the humerus is free, slight lateral traction on the upper humerus may be needed.</p></div>

Traction-countertraction technique for reducing anterior shoulder dislocations

Torn ulnar ligament

Joint Immobilization as Acute Treatment: Some Commonly Used Techniques

<span id="v56117774" class="anchor" ></span><div class="para" > <p >Types I through IV are physeal separations; the growth plate is separated from the metaphysis. Type II is the most common, and type V is the least common.</p></div>

Salter-Harris Classification of Physeal Disk (Growth Plate) Fractures

Ligaments of the shoulder joint

Sugar Tong Splint

<span id="v56117727" class="anchor" ></span><div class="para" > <p >Distraction, displacement, angulation, or shortening (overriding) may occur. </p></div><span id="v56117728" class="anchor" ></span><div class="para" > <p ><b >Distraction</b> is separation in the longitudinal axis. </p></div><span id="v56117729" class="anchor" ></span><div class="para" > <p ><b >Displacement</b> is the degree to which the fractured ends are out of alignment with each other; it is described in millimeters or bone width percentage. </p></div><span id="v56117730" class="anchor" ></span><div class="para" > <p ><b >Angulation</b> is the angle of the distal fragment measured from the proximal fragment. </p></div><span id="v56117731" class="anchor" ></span><div class="para" > <p >Displacement and angulation may occur in the ventral-dorsal plane, lateral-medial plane, or both.</p></div>

Spatial Relationship Between Fracture Fragments

Shoulder Anatomy (Anterior View)

Shoulder anatomy (anterior view)

<span id="v56117925" class="anchor" ></span><div class="para" > <p >Normally, the anterior humeral line, which is drawn along the anterior border of the humerus on a lateral radiograph, transects the middle of the capitellum. If the line transects none or only the anterior part of the capitellum, a distal humeral fracture with posterior displacement may be present.</p></div><span id="v56117926" class="anchor" ></span><div class="para" > <p >The radiocapitellar line, which is drawn through the midshaft of the radius, normally bisects the capitellum. If it does not, an occult fracture should be suspected.</p></div>

Anterior Humeral Line and Radiocapitellar Line

Key Anatomic Landmarks in the Proximal Humerus

Open Reduction With Internal Fixation (ORIF)

<span id="v56118029" class="anchor" ></span><div class="para" > <p >Normally, when the proximal interphalangeal joints are flexed to 90°, lines from the distal phalanges converge at a point on the proximal carpal bones. Deviation of one of these lines suggests a metacarpal fracture.</p></div>

Rotational deformity due to a fracture in the hand

<span id="v56117874" class="anchor" ></span><div class="para" > <p >If no structures are displaced or angulated, the fracture has one part. If one structure is angulated or displaced, the fracture has 2 parts.</p></div>

One- and 2-Part Fractures of the Proximal Humerus

<span id="v56117796" class="anchor" ></span><div class="para" > <p >The first numbers are the age at which ossification first appears on radiograph; the numbers in parentheses are the age at which union occurs.</p></div>

Epiphyseal Disks (Growth Plates)

Ligaments of the knee

Ligaments of the Ankle

Flail Chest

<span id="v912556" class="anchor" ></span><div class="para" > <p > FEF<sub >25–75%</sub><span class='symbol' > =</span> forced expiratory flow during expiration of 25 to 75% of the FVC; FEV<sub >1</sub><span class='symbol' > =</span> forced expiratory volume in the first second of forced vital capacity maneuver; FVC <span class='symbol' >=</span> forced vital capacity (the maximum amount of air forcibly expired after maximum inspiration).</p></div>

Normal Spirogram

<span id="v912876" class="anchor" ></span><div class="para" > <p >Arterial oxyhemoglobin saturation is related to PO2. PO2 at 50% saturation (P50) is normally 27 mm Hg. </p></div><span id="v36811896" class="anchor" ></span><div class="para" > <p >The dissociation curve is shifted to the right by increased hydrogen ion (H<sup >+</sup>) concentration, increased red blood cell 2,3-diphosphoglycerate (DPG), increased temperature (T), and increased PCO2. </p></div><span id="v36811897" class="anchor" ></span><div class="para" > <p >Decreased levels of H<sup >+</sup>, DPG, temperature, and PCO2 shift the curve to the left. </p></div><span id="v36811898" class="anchor" ></span><div class="para" > <p >Hemoglobin characterized by a rightward shifting of the curve has a decreased affinity for oxygen, and hemoglobin characterized by a leftward shifting of the curve has an increased affinity for oxygen.</p></div>

Oxyhemoglobin Dissociation Curve

<span id="v28584958" class="anchor" ></span><div class="para" > <p >During the first year, lung function improved in patients who quit smoking and declined in those who continued. Subsequently, the rate of decline in those who continued was twice that of those who quit. Function declined in those who relapsed and improved in those who quit regardless of when the change occurred. Based on data from Scanlon PD et al: Smoking cessation and lung function in mild-to-moderate chronic obstructive pulmonary disease; the Lung Health Study. <i >American Journal of Respiratory and Critical Care Medicine</i> 161:381–390, 2000.</p></div>

Changes in Lung Function (Percentage of Predicted FEV1) in Patients Who Quit Smoking Compared With Those Who Continue

<span id="v912580" class="anchor" ></span><div class="para" > <p >ERV <span class='symbol' >=</span> expiratory reserve volume; FRC <span class='symbol' >=</span> functional residual capacity; IC <span class='symbol' >=</span> inspiratory capacity; IRV <span class='symbol' >=</span> inspiratory reserve volume; RV <span class='symbol' >=</span> residual volume; TLC <span class='symbol' >=</span> total lung capacity; VC <span class='symbol' >=</span> vital capacity; V<sub >T</sub><span class='symbol' >=</span> tidal volume.</p></div><span id="v912581" class="anchor" ></span><div class="para" > <p >FRC <span class='symbol' >=</span> RV <span class='symbol' >+</span> ERV; IC <span class='symbol' >=</span> V<sub >T </sub><span class='symbol' >+</span> IRV; VC <span class='symbol' >=</span> V<sub >T</sub><span class='symbol' >+</span> IRV <span class='symbol' >+</span> ERV.</p></div>

Normal Lung Volumes

Some Causes of Mediastinal Masses in Adults

<span id="x000055" class="anchor" ></span><div class="para" > <p >* Based on presence of fever, weight loss, history of cancer, or other suggestive symptoms.</p></div><span id="x000056" class="anchor" ></span><div class="para" > <p >TB = tuberculosis.</p></div>

Diagnosis of Pleural Effusion

<span id="v56227835" class="anchor" ></span><div class="para" > <p >The ratio of the anteroposterior diameter of the finger at the nail bed (a–b) to that at the distal interphalangeal joint (c–d) is a simple measurement of finger clubbing. It can be obtained readily and reproducibly with calipers. If the ratio is <span class='symbol' >></span> 1, clubbing is present. Finger clubbing is also characterized by loss of the normal angle at the nail bed.</p></div>

Measuring finger clubbing

<span id="v56251761" class="anchor" ></span><div class="para" > <p >The ECG shows sinus tachycardia at a rate of 110 beats/minute, an S1Q3T3 and R <span class='symbol' >=</span> S in V1 in a patient with proven acute pulmonary embolism.</p></div>

An ECG in Pulmonary Embolism

<span id="e9f70f0e-63e8-4e7d-9ee2-524130f379bf" class="anchor" ></span><div class="para" > <p >The ventilation-perfusion scan demonstrates high probability for acute pulmonary embolism. The ventilation is relatively unaffected, while the perfusion images show large defects, particularly in the left lung.</p></div><span id="1265b677-6a46-4751-8d70-2be330ab5ad5" class="anchor" ></span><div class="para" > <p >Image courtesy of Victor F. Tapson, MD.</p></div>

Pulmonary Embolism (Ventilation-Perfusion Scan)

<span id="v56248515" class="anchor" ></span><div class="para" > <p >Data from <a rel="noopener nofollow" target="_blank" href="https://pubmed.ncbi.nlm.nih.gov/35927462/">Kemper AR, Newman TB, Slaughter JL, et al</a>. Clinical Practice Guideline Revision: Management of Hyperbilirubinemia in the Newborn Infant 35 or More Weeks of Gestation. <i >Pediatrics</i>. 2022;150(3):e2022058859. doi:10.1542/peds.2022-058859. (See reference for further details.)</p></div>

Phototherapy Thresholds for Infants With No Hyperbilirubinemia Neurotoxicity Risk Factors

Skull (Calvarial) Sutures

<span id="v81321126" class="anchor" ></span><div class="para" > <p >AO = aorta; LA = left atrium; LV = left ventricle; PA = pulmonary artery; RA = right atrium; RV = right ventricle.</p></div>

Congenitally Corrected Transposition of the Great Arteries (CCTGA)

<span id="v56117147" class="anchor" ></span><div class="para" > <p >The tricuspid valve is absent, and the right ventricle is hypoplastic. An atrial communication must be present. </p></div><span id="v56117148" class="anchor" ></span><div class="para" > <p >AO <span class='symbol' >=</span> aorta; IVC <span class='symbol' >=</span> inferior vena cava; LA <span class='symbol' >=</span> left atrium; LV <span class='symbol' >=</span> left ventricle; PA <span class='symbol' >=</span> pulmonary artery; PV <span class='symbol' >=</span> pulmonary veins; RA <span class='symbol' >=</span> right atrium; RV <span class='symbol' >=</span> right ventricle; SVC <span class='symbol' >=</span> superior vena cava.</p></div>

Tricuspid atresia with normally related great vessels

<span id="v56117089" class="anchor" ></span><div class="para" > <p >The pulmonary veins do not connect to the left atrium; instead, the entire pulmonary venous return enters systemic venous circulation through various connections. Systemic blood flow depends on right-to-left atrial shunting. </p></div><span id="v56117090" class="anchor" ></span><div class="para" > <p >AO <span class='symbol' >=</span> aorta; IVC <span class='symbol' >=</span> inferior vena cava; LA <span class='symbol' >=</span> left atrium; LV <span class='symbol' >=</span> left ventricle; PA <span class='symbol' >=</span> pulmonary artery; PV <span class='symbol' >=</span> pulmonary veins; RA <span class='symbol' >=</span> right atrium; RV <span class='symbol' >=</span> right ventricle; SVC <span class='symbol' >=</span> superior vena cava.</p></div>

Total anomalous pulmonary venous return

<span id="v56116683" class="anchor" ></span><div class="para" > <p >Pulmonary blood flow, all chamber volumes, and often pulmonary vascular resistance are increased. Atrial pressures are mean pressures.</p></div><span id="v56116684" class="anchor" ></span><div class="para" > <p >AO <span class='symbol' >=</span> aorta; IVC <span class='symbol' >=</span> inferior vena cava; LA <span class='symbol' >=</span> left atrium; LV <span class='symbol' >=</span> left ventricle; PA <span class='symbol' >=</span> pulmonary artery; PV <span class='symbol' >=</span> pulmonary veins; RA <span class='symbol' >=</span> right atrium; RV <span class='symbol' >=</span> right ventricle; SVC <span class='symbol' >=</span> superior vena cava.</p></div>

Atrioventricular septal defect (complete form)

Adrenal Hormone Synthesis

<span id="v56116981" class="anchor" ></span><div class="para" > <p >The primitive truncus does not divide into the pulmonary artery and aorta, resulting in a single large arterial trunk that overlies a large ventricular septal defect. </p></div>

Truncus arteriosus

<span id="v56116386" class="anchor" ></span><div class="para" > <p >Representative right heart oxygen saturation <span class='symbol' >=</span> 75%; representative left heart oxygen saturation <span class='symbol' >=</span> 95%. Atrial pressures are mean pressures.</p></div><span id="v56116388" class="anchor" ></span><div class="para" > <p >AO <span class='symbol' >=</span> aorta; IVC <span class='symbol' >=</span> inferior vena cava; LA <span class='symbol' >=</span> left atrium; LV <span class='symbol' >=</span> left ventricle; PA <span class='symbol' >=</span> pulmonary artery; PV <span class='symbol' >=</span> pulmonary veins; RA <span class='symbol' >=</span> right atrium; RV <span class='symbol' >=</span> right ventricle; SVC <span class='symbol' >=</span> superior vena cava.</p></div>

Normal circulation with representative right and left cardiac pressures (in mm Hg)

<span id="a767d8a5-9ce5-46c9-8024-edd1232f1595" class="anchor" ></span><div class="para" > <p >Although there are several tooth numbering systems, the one shown is the Universal Numbering System and is the one most commonly used in the United States.</p></div><span id="9c4ec96f-3f6e-4110-a41a-61cf59b8d64d" class="anchor" ></span><div class="para" > <p >(<a rel="noopener nofollow" target="_blank" href="https://dentaleducationhub.com/teeth-names-and-numbering-systems/">Dental Education Hub</a>: Teeth Names and Numbering Systems: You need to know. May 2020.)</p></div>

Identifying the Deciduous Teeth

<span id="x000046" class="anchor" ></span><div class="para" > <p >* PPV: Initiate resuscitation with room air (21% FiO2) for infants ≥ 35 weeks of gestational age or 21 to 30% FiO2 for infants < 35 weeks of gestational age. If SpO2 targets are not achieved, titrate inhaled oxygen concentration upward.</p></div><span id="x000047" class="anchor" ></span><div class="para" > <p >† 3:1 compression:ventilation ratio with a total of 90 compressions and 30 breaths/minute. Compressions and ventilations are delivered sequentially, not simultaneously. Thus, give 3 compressions at a rate of 120/minute, followed by 1 ventilation over 1/2 second.</p></div><span id="x000048" class="anchor" ></span><div class="para" > <p >CPAP = continuous positive airway pressure; ECG = electrocardiography; ETT = endotracheal tube; FiO2 = fractional inspired oxygen; HR = heart rate; PPV = positive pressure ventilation; SpO2 = oxygen saturation; UVC = umbilical venous catheter.</p></div><span id="x000049" class="anchor" ></span><div class="para" > <p >Based on Weiner GM: <i >Textbook of Neonatal Resuscitation,</i> ed. 8. Itasca, American Academy of Pediatrics, 2021.</p></div>

Algorithm for Resuscitation of Neonates

<span id="v56116850" class="anchor" ></span><div class="para" > <p >The left ventricle, ascending aorta, and aortic and mitral valves are hypoplastic; an atrial septal defect and a large patent ductus arteriosus are also present. </p></div><span id="v56116851" class="anchor" ></span><div class="para" > <p >AO <span class='symbol' >=</span> aorta; IVC <span class='symbol' >=</span> inferior vena cava; LA <span class='symbol' >=</span> left atrium; LV <span class='symbol' >=</span> left ventricle; PA <span class='symbol' >=</span> pulmonary artery; PDA <span class='symbol' >=</span> patent ductus arteriosus; PV <span class='symbol' >=</span> pulmonary veins; RA <span class='symbol' >=</span> right atrium; RV <span class='symbol' >=</span> right ventricle; SVC <span class='symbol' >=</span> superior vena cava.</p></div>

Hypoplastic left heart

<span id="v56116509" class="anchor" ></span><div class="para" > <p >Pulmonary blood flow and RA and RV volume are increased. (NOTE: Intracardiac pressures generally remain in the normal range throughout childhood.) With a large defect, RA and LA pressures are equal. </p></div><span id="x000156" class="anchor" ></span><div class="para" > <p >AO <span class='symbol' >=</span> aorta; IVC <span class='symbol' >=</span> inferior vena cava; LA <span class='symbol' >=</span> left atrium; LV <span class='symbol' >=</span> left ventricle; PA <span class='symbol' >=</span> pulmonary artery; PV <span class='symbol' >=</span> pulmonary veins; RA <span class='symbol' >=</span> right atrium; RV <span class='symbol' >=</span> right ventricle; SVC <span class='symbol' >=</span> superior vena cava.</p></div>

Atrial septal defect

<span id="v56122534" class="anchor" ></span><div class="para" > <p ><a rel="noopener nofollow" target="_blank" href="https://bmcpediatr.biomedcentral.com/articles/10.1186/1471-2431-13-59">Fenton T, Kim J</a>: A systematic review and meta-analysis to revise the Fenton growth chart for preterm infants. <i >BMC Pediatrics</i> 13:59, 2013. doi: 10.1186/1471-2431-13-59; used with permission.</p></div>

Fenton Growth Chart for Preterm Boys

Intussusception

Congenital Hydrocele

<span id="v56212590" class="anchor" ></span><div class="para" > <p >In the Cobb method, two lines are drawn on a posterior-anterior x-ray of the spine, one extending from the top of the most tilted upper vertebra and the other from the bottom of the most tilted lower vertebra. The angle formed by these lines is the Cobb angle.</p></div>

Cobb angle

<span id="v56123360" class="anchor" ></span><div class="para" > <p >Strabismus can involve both eyes; the left eye is shown here. The direction of the deviation is designated by the prefixes eso-, exo-, hyper-, and hypo-. When the deviation is visible, it is indicated by the suffixes -tropia and -phoria.</p></div>

Ocular Deviations in Strabismus

<span id="v56227859" class="anchor" ></span><div class="para" > <p >The child is positioned as shown. The knee is lower on the affected side because of posterior displacement in the developmentally dysplastic hip (arrow).</p></div>

Galeazzi Sign

<span id="v56115967" class="anchor" ></span><div class="para" > <p >Relative frequencies are based on a compilation of various sources.</p></div>

Types and Relative Frequencies of Esophageal Atresia and Tracheoesophageal Fistula

Types of Intracranial Hemorrhage

<span id="v56212362" class="anchor" ></span><div class="para" > <p >Adapted from Puig M: Body composition and growth. In <i >Nutrition in Pediatrics</i>, ed. 2, edited by WA Walker and JB Watkins. Hamilton, Ontario, BC Decker, 1996.</p></div>

Changes in body composition with growth and aging

<span id="v56122511" class="anchor" ></span><div class="para" > <p >Scores from neuromuscular and physical domains are added to obtain total score. </p></div><span id="06c4b87b-1997-499e-8ecf-7c938923a5e6" class="anchor" ></span><div class="para" > <p >(Adapted from <a rel="noopener nofollow" target="_blank" href="https://pubmed.ncbi.nlm.nih.gov/1880657/">Ballard JL, Khoury JC, Wedig K, et al</a>. New Ballard score, expanded to include extremely premature infants. <i >Pediatrics</i>. 1991;119(3):417–423. doi:10.1016/s0022-3476(05)82056-6; used with permission of the CV Mosby Company.)</p></div>

Assessment of Gestational Age—New Ballard Score

<span id="v56122976" class="anchor" ></span><div class="para" > <p ><a rel="noopener nofollow" target="_blank" href="https://bmcpediatr.biomedcentral.com/articles/10.1186/1471-2431-13-59">Fenton T, Kim J</a>: A systematic review and meta-analysis to revise the Fenton growth chart for preterm infants. <i >BMC Pediatrics</i> 13:59, 2013. doi: 10.1186/1471-2431-13-59; used with permission.</p></div>

Fenton Growth Chart for Preterm Girls

<span id="v56116899" class="anchor" ></span><div class="para" > <p >Pulmonary blood flow, LA and LV volumes, and ascending AO volume are increased.</p></div><span id="v56116900" class="anchor" ></span><div class="para" > <p >AO <span class='symbol' >=</span> aorta; LA <span class='symbol' >=</span> left atrium; LV <span class='symbol' >=</span> left ventricle; </p></div><span id="v56116901" class="anchor" ></span><div class="para" > <p >PA <span class='symbol' >=</span> pulmonary artery.</p></div>