This unit is about the brain, the body's frame, and its outer covering. Module 5 covers mental health conditions and brain emergencies. It runs from depression and schizophrenia to strokes, rising pressure inside the skull, and spinal cord injuries. Module 6 covers bones and muscles, skin problems, and burns. The exam has 50 questions, both multiple choice and select-all-that-apply.
A low mood that will not lift. The sadness or flatness lasts 2 weeks or more. Common symptoms are low energy, trouble sleeping, eating too much or too little, despair, guilt, hopelessness, and thoughts of suicide. Here are the subtypes:
| Category | Examples |
|---|---|
| Biological | Neurotransmitters out of balance (serotonin, dopamine, norepinephrine), hormone shifts, and too little sunlight or vitamin D. |
| Genetic | Mood disorders that run in the family. |
| Psychosocial | Trauma, grief, long-term stress, and being cut off from others. |
| Medical | Long-term illness, side effects of medicine, and changes after childbirth. |
A serious disorder with a higher-than-average suicide risk. The mood swings hard between mania and depression:
Fear or worry that is too much and gets in the way of daily life. It hits the mind AND the body, bringing a fast heart rate, high blood pressure, and restlessness. Here are the types:
| Type | Main Feature |
|---|---|
| GAD | Worry and fear that are broad and never let up. |
| Social anxiety | Fear of being around people, or in public. |
| Panic disorder | Sudden, intense distress set off by stress, fear, or effort. |
| Specific phobia | Strong fear of one thing, such as heights or needles. |
These two used to sit with the anxiety disorders. In DSM-5 each one has its own chapter, so do not file them under anxiety. Anxiety is still part of the picture in both.
| Condition | Its own chapter | Main Feature |
|---|---|---|
| OCD | Obsessive-compulsive and related disorders | Two parts, and you need both. Obsessions are unwanted thoughts, images, or urges that push their way in and will not leave. Compulsions are repeated acts or mental rituals done to push the distress back down. Naming only the repeated acts leaves out half the disorder. |
| PTSD | Trauma- and stressor-related disorders | Comes after a traumatic event, with flashbacks, nightmares, avoiding reminders, a jumpy nervous system, and dark shifts in mood and thinking. |
A long-term, severe disorder. It pulls a person away from reality and disturbs thinking and daily function. It is tied to dopamine being out of balance. The symptoms fall into two groups:
| Positive (added), from too much dopamine | Negative (lost), from too little dopamine |
|---|---|
| Hallucinations, delusions, speech that does not hang together, and paranoia. Together these are psychosis | Alogia, meaning little speech. Avolition, meaning no drive. Anhedonia, meaning no pleasure. Also pulling away from people |
Positive means something abnormal was added, like a hallucination. Negative means normal function was taken away, like losing all drive.
A brain development disorder that usually starts in childhood, and it can carry into adult life. Dopamine and norepinephrine are out of balance, and both run low. The core symptoms are trouble paying attention, being very active, and acting on impulse. Risk factors are genes, a traumatic brain injury, and toxins before birth such as lead, alcohol, and cigarette smoke. It often comes with low self-esteem and trouble at school and with friends.
ICP is the pressure inside the hard skull. The skull holds 3 things, which is the Monro-Kellie idea: brain tissue, blood, and cerebrospinal fluid (CSF). The skull cannot stretch. So if any one of the three grows, the pressure climbs and squeezes the brain. Here are the causes:
| Component ↑ | Examples |
|---|---|
| Blood | Wider vessels from a high CO₂, blocked veins, very high BP, and bleeding. |
| Brain tissue | A tumor, or swelling after an injury or a bleed. |
| CSF | Hydrocephalus, where drainage is blocked or too much CSF is made. |
| Early | Late (and ominous) |
|---|---|
| Headache, nausea, vomiting, sleepiness, confusion, double vision | Cushing's Triad, pupils fixed and wide from pressure on cranial nerve III, a drop in level of consciousness, odd posturing, and coma |
Posturing shows severe damage. Decorticate means the arms bend in toward the core. Think "de-COR-ticate, arms to the core." Decerebrate means the arms stretch out straight, and that is worse.
| Type | Telltale Sign |
|---|---|
| Tension (most common) | A both-sided "tight band" around the head. It comes from tight muscles, poor posture, and stress. |
| Sinus | Over the forehead or under the eyes, with face pain. It often comes with a cold or stuffy nose. |
| Cluster | One-sided, stabbing pain around one eye. The eye waters and the nose runs. It is its own headache type, not a migraine. |
| Migraine | Severe, one-sided, and pounding. It brings nausea and vomiting, plus trouble with light and sound. Moving makes it worse. |
A stroke, also called a cerebrovascular accident or CVA, is the death of brain cells when blood flow is cut off. There are two very different types. Telling them apart matters, because their treatments are opposites.
| Ischemic (about 87%) | Hemorrhagic (about 13%) | |
|---|---|---|
| Cause | A vessel is blocked. The clot may form on the spot, from atherosclerosis, or travel there, often from A-fib | A weakened vessel bursts |
| Risk factors | Atherosclerosis, atrial fibrillation, and clots | High blood pressure, the #1 cause, plus aneurysm and trauma |
| Classic signs | A drooping face, weakness on one side, changed speech, and confusion | A sudden, severe "thunderclap" headache, with sudden vomiting or loss of consciousness |
| Treatment | Fibrinolytics, the clot busters. Only after a CT rules out a bleed | Stop the bleeding and control the BP. NO clot busters |
A brief blockage where the symptoms go away completely and leave no lasting damage. Treat it as a warning sign, because a full stroke is now much more likely. The modern definition rests on whether tissue was damaged, not on a strict time limit.
One-sided paralysis of the facial nerve, which is cranial nerve VII. The cause is usually unknown, though herpes infection and Lyme disease are suspected. The face is the only part affected. The arms and legs are fine. That is the key way to tell it from a stroke:
| Type | Where It Is, and How Fast |
|---|---|
| Epidural hematoma | Above the dura, between the skull and the dura. It is an artery, so it bleeds fast and hard. |
| Subdural hematoma | Below the dura, between the dura and the arachnoid. It is a vein, so it is usually slower. |
| Intracerebral hemorrhage | Inside the brain tissue. This is one kind of hemorrhagic stroke. It comes from high BP, an aneurysm, or trauma. |
| Subarachnoid hemorrhage | In the subarachnoid space. It often comes from a burst berry aneurysm. |
CSF piles up in the ventricles. Either the drainage is blocked, which is most common, or too much CSF is made. The signs depend on age:
| Infant (soft skull) | Adult (fixed skull) |
|---|---|
| The head grows larger, the level of consciousness changes, and the baby is irritable | Headache, vomiting, clumsy movement, loss of bladder control, sleepiness, coma |
An infant's skull bones have not fused yet, so the head can grow. An adult's skull is fused, so the pressure climbs instead.
| Meningitis | Encephalitis | |
|---|---|---|
| What is inflamed | The meninges, the membranes around the brain | The brain tissue itself |
| Cause | Bacteria, which is more severe, or a virus, which often clears on its own | Usually a virus, and herpes is the most common |
| Telltale Sign | The classic triad: a stiff neck (nuchal rigidity), a severe headache, and fever, plus trouble with light | Vague at first: fever, headache, trouble with light, and confusion |
Damage that cuts off the motor, sensory, or autonomic pathways. The most-injured areas are the cervical and lumbar spine, because they move the most. The level of injury decides what is lost:
Types of injury, by how it happened: flexion, as in a head-on car crash. Hyperextension, as in striking the chin in a fall. Compression, as in diving into shallow water or having an object land on the head. Subluxation, as in falling off a horse.
| Spinal Shock | Neurogenic Shock | |
|---|---|---|
| What it is | A brief loss of reflexes, with limp muscles, below the injury | Sympathetic signals are cut off, so blood pressure and heart rate go unstable. The injury is usually above T6 |
| Signs | No deep tendon reflexes, limp paralysis, and no feeling below the injury | Low blood pressure plus a slow heart rate, because nothing balances the parasympathetic system |
| How it runs | You will not know how bad the injury is for 4–6 weeks | The unstable blood pressure and heart rate usually run one to three weeks, not a day or two |
A dangerous surge of sympathetic activity in patients with an SCI at T6 or higher. Something irritating below the injury sets it off, such as a full bladder, constipation, or tight clothing. The body cannot pass signals across the injury to settle it down:
Use it to spot life-threatening problems fast in trauma, especially when the patient cannot respond. Work through it in order:
| Letter | What You Check |
|---|---|
| A — Airway | Is the airway blocked? |
| B — Breathing | Is breathing hard work? Do the breath sounds seem normal? |
| C — Circulation | Heart rate, pale skin, and how fast color returns to a pressed nail bed. |
| D — Disability | Nerve function. Can the patient respond? |
| E — Exposure/Environment | Uncover the patient to find injuries. Also think about the setting, such as cold and hypothermia. |
Use it to check the health of the tissue around a fracture or dislocation. Ask whether the bone has hurt a nearby nerve, artery, or vein.
| P | What It Means |
|---|---|
| Pain | Can the patient feel pain? |
| Pulse | Is blood still moving through? |
| Pallor | Pale skin means poor blood flow. |
| Paresthesia | Can the patient feel touch? |
| Paralysis | Can the patient move it? |
| Curve | What It Looks Like |
|---|---|
| Kyphosis | Too much forward rounding of the upper back, the "hunchback" shape. It often comes with osteoporosis. |
| Lordosis | Too much inward curve of the lower back, the "swayback" shape. |
| Scoliosis | A sideways curve of the spine. |
Four bone disorders that are easy to mix up. The key for each one is the problem underneath.
| Disorder | The Core Problem, and Key Facts |
|---|---|
| Osteoporosis | Minerals are lost from bone. The osteoclasts that break bone down outwork the osteoblasts that build it. The bone turns porous and brittle. Risk factors: menopause and low estrogen, age, Caucasian or Asian race, smoking, alcohol, steroids, too little calcium, sitting too much, and an overactive thyroid. Signs: bone pain, often in the back, plus kyphosis, loss of height, and easy fractures. |
| Osteomalacia | "Soft bone." The bone cannot take up minerals, because of too little vitamin D. In children this is called rickets. It goes with low calcium and phosphate, a high PTH, and kidney disease. Signs: bone pain and deformed bones, such as bowed legs and a jutting breastbone. |
| Osteoarthritis (OA) | "Wear and tear," with no immune attack. The cartilage wears away, and bone grinds on bone. It cannot be reversed, and it worsens slowly. The pain gets WORSE as the day goes on, and with use. It usually hits one side. Risks: age, being female, extra weight, an old injury, and using the same joint over and over. |
| Osteomyelitis | A bacterial infection INSIDE the bone. The risk is high with an open fracture, since the bone meets skin and the outside world. Signs: constant bone pain that rest does not ease, plus fever, chills, night sweats, warmth, and tenderness. An early X-ray may look normal. Untreated, it can lead to sepsis. |
| Complication | The Patho, and the Signs |
|---|---|
| Compartment syndrome | Pressure inside a muscle compartment climbs so high from swelling that it squeezes the nerves and vessels, so the tissue goes short on blood. The 6 P's: sudden severe Pain, Paresthesia, Pallor, Paralysis, Pulselessness, and Poikilothermia, which means the limb turns cool. This is an emergency. |
| Fat embolism | Fat droplets from the yellow bone marrow get into the blood and plug up vessels. It shows up 24 to 72 hours after the injury, not right away. The triad: confusion from the brain, petechiae, a pinpoint rash on the chest and upper body, and shortness of breath from the lungs. It is common after a long-bone fracture. |
| Rhabdomyolysis | Muscle breaks down fast, from overuse, trauma, a crush injury, or statins. That dumps myoglobin and potassium into the blood. The triad: muscle pain (myalgia), brown urine (myoglobinuria), and weakness. Labs show a high creatine kinase and a high potassium. It can injure the kidneys. |
| Injury | What Is Torn or Stretched |
|---|---|
| Sprain | A ligament, which joins bone to bone. It comes from a fast twist or pull. Signs are bruising, swelling, a wobbly joint, and pain on movement. It is common at joints, like the ankle. |
| Strain | A muscle or tendon. It is common in the big muscle groups, such as the low back, calf, and hamstring. |
| Rotator cuff injury | The shoulder. There is pain when lifting the arm out to the side (abduction), plus popping, clicking, and weakness. |
| ACL tear | A knee ligament. The classic cause is a "plant and twist" with no contact. It raises the risk of osteoarthritis later. |
Most come from Staphylococcus or Streptococcus. The key difference is how deep they go:
| Infection | How Deep, and the Telltale Sign |
|---|---|
| Impetigo | On the surface. The classic look is honey-colored crusts. It spreads very easily, and it is common in children. |
| Cellulitis | A deep infection of the dermis and the fat layer below it (hypodermis). The area is red, warm, swollen, and tender. The drainage can spread it. It can reach the blood and cause sepsis. |
Surface fungi, such as tinea, known as ringworm, and candida, love warm, damp places. Think skin folds, feet, and the groin. Deep fungal infections show up mainly in patients with a weak immune system.
| Condition | The Patho, and the Telltale Sign |
|---|---|
| Eczema (atopic dermatitis) | Long-term inflammation. The skin is dry, itchy, and red. It is common in childhood, and it shows up classically on the bend side of joints, behind the knees and inside the elbows. It travels with asthma and allergies. |
| Urticaria (hives) | An itchy "wheal and flare" rash. IgE sets off a histamine release, so you see it with allergic reactions. |
| Acne vulgaris | Inflammation of the hair follicle and its oil gland. Three things go wrong: more oil (sebum), a follicle plugged with keratin, and bacteria (Propionibacterium, now called Cutibacterium). |
| Psoriasis | Long-term and autoimmune. It makes thick, silvery, scaly plaques, because the skin cells turn over far too fast. |
| Cancer | How It Behaves |
|---|---|
| Basal cell carcinoma | The most common one. It rarely spreads, so it is the least dangerous. |
| Squamous cell carcinoma | It can spread to lymph nodes and organs. |
| Melanoma | The most dangerous one. It spreads easily. Watch the ABCDEs. |
| Letter | Warning Sign |
|---|---|
| A — Asymmetry | One half does not match the other. |
| B — Border | The edges are ragged, uneven, or blurry. |
| C — Color | There is more than one color inside the spot. |
| D — Diameter | It is wider than about 6 mm, the size of a pencil eraser. |
| E — Evolving | It is changing in size, shape, or color over time. |
| Pressure Ulcer (decubitus) | Venous Stasis Ulcer | |
|---|---|---|
| Cause | Pressure that never lets up over a bony spot cuts off blood flow, and the skin breaks down. | The valves in the veins stop working, so fluid and waste pile up in the legs. That brings swelling and tissue damage. |
| Risk factors | Not moving, pressure, shearing, rubbing, and moisture. Also poor nutrition, older age, and steroids. | Long-term poor vein flow, swollen legs, and varicose veins. |
| Where you see it | Over bony points, such as the sacrum, heels, and hips. | The lower legs, usually around the ankles. |
The things that cause a pressure ulcer split into two groups. Outside forces are pressure, shear, rubbing, and moisture. Inside factors are not moving, poor nutrition, long-term illness, and older age.
| Degree | Depth, and How It Looks |
|---|---|
| Superficial (1st degree) | The epidermis only. It is red and painful, with no blisters, like a sunburn. |
| Partial thickness (2nd degree) | The epidermis plus part of the dermis. It is red, blistered, and very painful. |
| Full thickness (3rd degree) | Through the whole dermis, down into the fat. It looks white, charred, or leathery. The center is often painless, because the nerves are gone. |
| Pair | How They Differ |
|---|---|
| Cushing's Triad vs shock | Cushing's means BP up, HR down, and RR down, from high ICP. Shock means BP down and HR up. |
| Ischemic vs hemorrhagic stroke | A clot, where you give a clot buster after the CT, versus a bleed, tied to high BP and a thunderclap headache. |
| Epidural vs subdural | Arterial and fast, versus venous and slow. |
| Neurogenic shock vs autonomic dysreflexia | Both slow the heart. One drops the BP, the other sends it very high. |
| Osteoporosis vs osteomalacia | Too little bone, from lost minerals, versus soft bone, from too little vitamin D. |
| OA vs RA timing | OA is worse through the day. RA is worse in the morning. |
| Sprain vs strain | Ligament versus muscle or tendon. |
| Impetigo vs cellulitis | A honey crust at the surface versus a deep infection in the dermis. |
| Basal cell vs melanoma | Common and rarely spreading, versus the deadliest, which you track with ABCDE. |