UC 8022 Exam 5 practice questions
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Questions and Answers

What stimulates osteoblasts to produce osteocalcin?

  • Vitamin A
  • Vitamin K
  • Vitamin D (correct)
  • Vitamin C

    • Which type of bone cells follow Wolfe's law, shaping bone according to its function?

  • Osteoclasts
  • Osteoblasts (correct)
  • Osteocytes
  • Mesenchymal cells

    • What is the main function of osteocytes in bone maintenance?

  • Secreting hydrochloric acid
  • Developing dendritic processes
  • Synthesizing osteoid
  • Coordinating osteoblast and osteoclast functions (correct)

    • Which cells are responsible for resorbing bone by secreting hydrochloric acid and enzymes?

    <p>Osteoclasts</p> Signup and view all the answers

    Which type of bone is also known as cortical bone?

    <p>Compact bone</p> Signup and view all the answers

    What do osteoclasts attach to bone through in order to resorb it?

    <p>Integrins by podosomes</p> Signup and view all the answers

    What is the basic structural unit in compact bone?

    <p>Haversian system</p> Signup and view all the answers

    What type of bone lacks the Haversian system and is filled with red bone marrow?

    <p>Spongy bone</p> Signup and view all the answers

    In bone repair, what phase replaces the callus with lamellar bone or trabecular bone?

    <p>Callus formation</p> Signup and view all the answers

    Which type of joints are directly united to bone by dense fibrous connective tissue?

    <p>Fibrous joints</p> Signup and view all the answers

    What type of joint is characterized by bones being united by a pad or disk of fibrocartilage?

    <p>Symphysis</p> Signup and view all the answers

    Which phase involves the activation of the remodeling cycle and the resorption of old bone in the bone-remodeling process?

    <p>Activation</p> Signup and view all the answers

    What is the main difference between a sprain and an avulsion?

    <p>Sprain is a tear in a ligament, while avulsion is a complete separation of a tendon or ligament from its bony attachment site.</p> Signup and view all the answers

    Which condition is characterized by the inflammation of a bursa?

    <p>Bursitis</p> Signup and view all the answers

    Myositis ossificans is known to happen more often in athletes due to:

    <p>Repetitive trauma to the same area before the muscle has appropriate time to heal</p> Signup and view all the answers

    What is the classic triad of symptoms seen in Rhabdomyolysis?

    <p>Muscle pain, weakness, dark urine</p> Signup and view all the answers

    Compartment syndrome is mainly characterized by:

    <p>Pain out of proportion to the injury and paresthesia</p> Signup and view all the answers

    What is the defining characteristic of osteoporosis?

    <p>Imbalance of bone resorption and formation</p> Signup and view all the answers

    What is the primary function of muscle in the human body?

    <p>To accomplish work</p> Signup and view all the answers

    Which type of muscle fibers are known for slow contractions?

    <p>Type I fibers</p> Signup and view all the answers

    What is the purpose of the Ryanodine receptors (RyRs) in muscle contraction?

    <p>Control calcium release</p> Signup and view all the answers

    Which phase of muscle contraction involves the formation of a cross-bridge between actin and myosin filaments?

    <p>Contraction phase</p> Signup and view all the answers

    In which type of muscle contraction does the muscle maintain a constant length as tension is increased?

    <p>Isometric contraction</p> Signup and view all the answers

    What is the primary characteristic of an open or compound fracture?

    <p>Skin is broken</p> Signup and view all the answers

    What distinguishes a transverse fracture from an oblique fracture?

    <p>Occurs straight across the bone</p> Signup and view all the answers

    What is the result of an improper reduction during bone healing processes?

    <p>Nonunion</p> Signup and view all the answers

    Which term describes an injury involving a tendon connecting muscle to bone?

    <p>Strain</p> Signup and view all the answers

    What happens during sarcopenia, an age-related muscular change?

    <p>Decrease in muscle mass</p> Signup and view all the answers

    What stimulates osteoblasts to produce osteocalcin?

    <p>Parathyroid hormone</p> Signup and view all the answers

    Which cells are responsible for signaling osteoblasts and osteoclasts to form and reabsorb bone?

    <p>Osteocytes</p> Signup and view all the answers

    What is the main function of integrins attached to podosomes in osteoclasts?

    <p>Binding to bone</p> Signup and view all the answers

    What kind of cells cause resorption of bone by secreting hydrochloric acid and a protease enzyme?

    <p>Osteoclasts</p> Signup and view all the answers

    During bone repair, what do osteoblasts synthesize that brings on the formation of new bone?

    <p>Osteoid</p> Signup and view all the answers

    What property of bones does Wolfe's law refer to?

    <p>Bone shape being determined by function</p> Signup and view all the answers

    What is the primary function of the Haversian system in compact bone?

    <p>Providing channels for bone cell communication</p> Signup and view all the answers

    In bone repair, what role does hematoma formation play?

    <p>Initiates clot formation</p> Signup and view all the answers

    What is the main difference between symphysis joints and synchondrosis joints?

    <p>Type of cartilage connecting bones</p> Signup and view all the answers

    During the remodeling phase of bone repair, what happens at the endosteal surfaces?

    <p>Resorption of old bone</p> Signup and view all the answers

    What differentiates fibrous joints from cartilaginous joints structurally?

    <p>Type of connective tissue uniting bones</p> Signup and view all the answers

    What distinguishes synarthrosis joints from diarthrosis joints based on their mobility?

    <p>Type of movement allowed</p> Signup and view all the answers

    What is the primary function of proteoglycans in cartilage?

    <p>Ensure a fluid film is present on cartilage</p> Signup and view all the answers

    Which ion channels control calcium release in skeletal muscles?

    <p>Ryanodine receptors</p> Signup and view all the answers

    What is the main function of the sarcolemma in muscle contraction?

    <p>Propagates impulse</p> Signup and view all the answers

    What is the 'all or nothing' principle in muscle contraction?

    <p>Either a muscle fiber contracts completely or not at all</p> Signup and view all the answers

    Which type of muscle contraction maintains a constant length as tension is increased?

    <p>Isometric contraction</p> Signup and view all the answers

    What is the result of an open or compound fracture?

    <p>Skin is broken</p> Signup and view all the answers

    During aging, what happens to muscle strength and bulk?

    <p>Decrease significantly</p> Signup and view all the answers

    What occurs during a strain injury?

    <p>Tear or injury to a tendon</p> Signup and view all the answers

    Which type of fractures runs parallel to the long axis of the bone?

    <p>Linear</p> Signup and view all the answers

    What is the key difference between epicondylitis and tendinopathy?

    <p>Epicondylitis is inflammation of a tendon's attachment to bone, while tendinopathy refers to painful degradation of collagen fibers.</p> Signup and view all the answers

    What differentiates Myositis Ossificans from Rhabdomyolysis?

    <p>Myositis Ossificans is a reaction to a bruise causing bone-like structure in the muscle, whereas Rhabdomyolysis results in rapid muscle breakdown.</p> Signup and view all the answers

    What are the clinical manifestations of Compartment Syndrome?

    <p>Paresthesia, dark urine, and pulselessness</p> Signup and view all the answers

    How does Rhabdomyolysis differ from Osteoporosis?

    <p>Rhabdomyolysis involves life-threatening muscle breakdown, while Osteoporosis is characterized by reduced bone mass and density.</p> Signup and view all the answers

    What characterizes the pathophysiology of Avulsion injuries?

    <p>Complete separation of a tendon or ligament from its bony attachment site</p> Signup and view all the answers

    How does Subluxation differ from Dislocation?

    <p>Subluxation leads to complete loss of motion in the joint, while Dislocation only partially loses connection between bones.</p> Signup and view all the answers

    What skin lesion is characterized by an irregular red line produced by capillary dilation?

    <p>Wheal</p> Signup and view all the answers

    Which of the following represents full-thickness skin loss involving damage to muscle, bone, or supporting structures?

    <p>Stage IV pressure ulcer</p> Signup and view all the answers

    Which skin lesion is caused by excessive collagen formation during the healing process?

    <p>Keloid</p> Signup and view all the answers

    What type of lesion presents as an elevated, circumscribed, and superficial lesion filled with serous fluid?

    <p>Vesicle</p> Signup and view all the answers

    What skin manifestation results from a loss of part of the epidermis and appears as a depressed, moist, and glistening area?

    <p>Erosion</p> Signup and view all the answers

    Which factor is NOT related to the mechanisms for crystal deposition in gout?

    <p>Increased uric acid secretion in the kidneys</p> Signup and view all the answers

    What is the distinguishing characteristic between physiologic and pathologic contractures?

    <p>Cause of muscle fiber shortening</p> Signup and view all the answers

    Which symptom is NOT typically seen in patients with fibromyalgia?

    <p>Nausea</p> Signup and view all the answers

    What element does NOT contribute to disuse atrophy in muscles?

    <p>Increased protein synthesis</p> Signup and view all the answers

    What is the primary source of muscle weakness in polymyositis?

    <p>Humoral dysregulation</p> Signup and view all the answers

    What distinguishes osteosarcoma from chondrosarcoma based on their clinical manifestations?

    <p>Infiltration of spongy bone</p> Signup and view all the answers

    Which factor contributes to the classification of a malignant bone tumor?

    <p>Prominent nucleolus</p> Signup and view all the answers

    What differentiates fibrosarcoma from myelogenic tumors based on their characteristics?

    <p>Development from bone marrow cells</p> Signup and view all the answers

    How does osteosarcoma differ from myelogenic tumors based on their location?

    <p>Frequently affects the metaphyses of long bones</p> Signup and view all the answers

    What distinguishes chondrosarcoma from fibrosarcoma based on their composition?

    <p>Contains lobules of hyaline cartilage</p> Signup and view all the answers

    What type of skin disorder is characterized by a T-cell autoimmune-mediated mechanism?

    <p>Psoriasis</p> Signup and view all the answers

    Which skin condition involves acute recurring episodes with 'bull's eye' or target lesions?

    <p>Erythema Multiforme</p> Signup and view all the answers

    Which skin disease is caused by circulating IgG autoantibodies directed against cell surface adhesion molecules?

    <p>Pemphigus</p> Signup and view all the answers

    Which skin disorder involves a butterfly pattern over the nose and cheeks and can lead to systemic lupus erythematosus?

    <p>Discoid Lupus Erythematosus</p> Signup and view all the answers

    Which skin condition involves involvement of T cells, adhesion molecules, inflammatory cytokines, and antigen-presenting cells?

    <p>Lichen Planus</p> Signup and view all the answers

    Which skin infection is caused by candida albicans and is normally found on skin, in the gastrointestinal tract, and in the vagina?

    <p>Candidiasis</p> Signup and view all the answers

    What skin infection is characterized by cauliflower-like lesions occurring in moist areas such as the glans of the penis, vulva, and anus, and is highly contagious and sexually transmitted?

    <p>Warts</p> Signup and view all the answers

    Which viral infection presents with initial pain and paresthesia localized to a dermatome, followed by vesicular eruptions along specific dermatome areas like the face, neck, or lower back?

    <p>Chickenpox</p> Signup and view all the answers

    What characterizes cellulitis as an infection of the skin?

    <p>Infection of dermis and subcutaneous tissue</p> Signup and view all the answers

    What skin infection is a rapidly spreading inflammation starting in the fascia, muscles, and subcutaneous fat with subsequent necrosis of the overlying skin?

    <p>Necrotizing Fasciitis</p> Signup and view all the answers

    Which factor contributes to the progression of albicans from a commensal organism to a pathogen?

    <p>Systemic administration of antibiotics</p> Signup and view all the answers

    What is the main cause of the thin-walled pustule producing a whitish-yellow, curdlike substance?

    <p>Histamine release causing endothelial cell contraction</p> Signup and view all the answers

    What distinguishes ticks from other insects in terms of feeding behavior?

    <p>Releasing toxins during feeding</p> Signup and view all the answers

    Which gene mutation is associated with Squamous Cell Carcinoma of the skin?

    <p>TP53</p> Signup and view all the answers

    How does Kaposi Sarcoma primarily manifest on the skin?

    <p>Purple-brown macules progressing into nodules</p> Signup and view all the answers

    Which type of cells line the CSF-filled cavities of the CNS?

    <p>Ependymal cells</p> Signup and view all the answers

    What is the term for the degeneration of a nerve fiber separated from its nutritive source by injury or disease?

    <p>Wallerian degeneration</p> Signup and view all the answers

    What is the process where myelin sheath reforms into Schwann cells after nerve injury?

    <p>Schwann cell remyelination</p> Signup and view all the answers

    Where are neurotransmitters stored before release across the synaptic cleft?

    <p>Synaptic knobs</p> Signup and view all the answers

    Which cells are responsible for removing debris through phagocytosis in the CNS?

    <p>Microglia</p> Signup and view all the answers

    What is the function of the reticular formation in the Central Nervous System?

    <p>Regulates vital reflexes like cardiovascular and respiratory function</p> Signup and view all the answers

    Which lobe of the Forebrain is responsible for the reception and interpretation of speech?

    <p>Temporal lobe</p> Signup and view all the answers

    What is a characteristic feature of the cerebellum's function?

    <p>Conscious and unconscious muscle synergy</p> Signup and view all the answers

    Which structure in the Brain Stem controls important activities like heart rate, respiration, swallowing, and vomiting?

    <p>Medulla Oblongata</p> Signup and view all the answers

    Which area in the cerebral cortex is primarily responsible for goal-oriented behavior and short-term memory?

    <p>Prefrontal cortex</p> Signup and view all the answers

    What is the main cause of Glaucoma?

    <p>Increased pressure that compresses and damages the optic nerve</p> Signup and view all the answers

    Which type of hearing loss is age-related and usually affects high frequencies?

    <p>Sensorineural hearing loss</p> Signup and view all the answers

    What does vertigo refer to?

    <p>Sensation of spinning due to inflammation of the ear's semicircular canals</p> Signup and view all the answers

    What do cognitive functions related to awareness embody?

    <p>Awareness of self, environment, and affective states</p> Signup and view all the answers

    Which condition is characterized by a lack of verbal response to external stimuli?

    <p>Coma</p> Signup and view all the answers

    What causes functional hearing loss?

    <p>Emotional or psychologic factors</p> Signup and view all the answers

    What is the main cause of tinnitus?

    <p>Ringing of the ears due to emotional factors</p> Signup and view all the answers

    What is the primary function of the reticular-activating system?

    <p>Mediating wakefulness and consciousness</p> Signup and view all the answers

    What differentiates conductive hearing loss from sensorineural hearing loss?

    <p>Impaired sound conduction characterizes conductive, Organ of corti impairment characterizes sensorineural.</p> Signup and view all the answers

    How does mixed hearing loss differ from functional hearing loss?

    <p>Mixed hearing loss involves both conductive and sensorineural losses, Functional hearing loss is related to emotional or psychologic factors.</p> Signup and view all the answers

    What is the distinguishing feature between aseptic meningitis and fungal meningitis?

    <p>Type of inflammatory reaction</p> Signup and view all the answers

    Which characteristic is common among the most common forms of encephalitis?

    <p>Caused by arthropod-prone viruses</p> Signup and view all the answers

    What is the primary cause of demyelination in Multiple Sclerosis?

    <p>Viral infection</p> Signup and view all the answers

    What is a characteristic symptom of Cerebellar type multiple sclerosis?

    <p>Motor ataxia</p> Signup and view all the answers

    Which type of motor neurons are diffusely affected by Amyotrophic Lateral Sclerosis (ALS)?

    <p>Lower and upper motor neurons</p> Signup and view all the answers

    What is the primary cause of muscle weakness in Myasthenia Gravis?

    <p>Defect in nerve impulse transmission at NMJ</p> Signup and view all the answers

    What is the distinguishing feature of encephalitis from meningitis?

    <p>Involvement of the optic nerve</p> Signup and view all the answers

    Which condition results in scarring or plaque formation in the CNS?

    <p>Multiple Sclerosis</p> Signup and view all the answers

    What distinguishes Amyotrophic Lateral Sclerosis (ALS) from Myasthenia Gravis?

    <p>Disease progression leading to respiratory failure</p> Signup and view all the answers

    Which neurological condition primarily involves upper motor neurons?

    <p>Amyotrophic Lateral Sclerosis (ALS)</p> Signup and view all the answers

    What autoimmune disease results from a defect in nerve impulse transmission at the neuromuscular junction?

    <p>Myasthenia Gravis</p> Signup and view all the answers

    Which clinical manifestation is common between Myasthenia Crisis and Cholinergic Crisis?

    <p>Respiratory insufficiency</p> Signup and view all the answers

    What distinguishes myasthenic crisis from cholinergic crisis?

    <p>Onset time from taking anticholinesterase medication</p> Signup and view all the answers

    What is the primary cause of muscular fatigue in Myasthenia Gravis?

    <p>Defect in nerve impulse transmission at the NMJ</p> Signup and view all the answers

    What causes progressive weakness leading to respiratory failure in Amyotrophic Lateral Sclerosis?

    <p>Degeneration of lower and upper motor neurons</p> Signup and view all the answers

    Which autoimmune disease results from degeneration of non-motor neurons in the cortices and spinal cord?

    <p>Amyotrophic Lateral Sclerosis (ALS)</p> Signup and view all the answers

    What is the characteristic sign that differentiates encephalitis from meningitis?

    <p>Specific cranial nerve dysfunction</p> Signup and view all the answers

    Which virus is NOT commonly associated with causing encephalitis?

    <p>Influenza virus</p> Signup and view all the answers

    Which autoimmune disease is characterized by scarring or formation of plaque in the central nervous system?

    <p>Multiple Sclerosis (MS)</p> Signup and view all the answers

    In which type of Multiple Sclerosis do patients typically experience weakness, numbness, or both in one or more limbs?

    <p>Spinal type</p> Signup and view all the answers

    Which feature is NOT characteristic of Amyotrophic Lateral Sclerosis (ALS)?

    <p>Progressive weakness leading to bradycardia</p> Signup and view all the answers

    What distinguishes Myasthenia Crisis from Cholinergic Crisis?

    <p>Onset time after drug intake</p> Signup and view all the answers

    Study Notes

    Cold Injuries

    • A skin injury from exposure to extreme cold temperatures, affecting fingers, toes, ears, nose, and cheeks
    • Burning reaction caused by alternating cycles of vasoconstriction and vasodilation
    • Inflammation and reperfusion are part of the pathophysiology
    • Clinical manifestations: skin appears white or yellowish, waxy, and firm to the touch

    Burns

    • A cutaneous injury resulting from thermal, chemical, or electrical causes
    • Multisystem injuries with interactions with shock, inflammation, and immunocompromised state
    • Burn wound depths:
      • Partial-thickness injury: involves only the epidermis, no injury to underlying dermal and subcutaneous tissue
      • Clinical manifestations: local pain, erythema, and no blisters until 24 hours after injury
      • Superficial partial-thickness injury: thin-walled, fluid-filled blisters develop within minutes after injury
      • Deep partial-thickness injury: involves the entire dermis, sparing skin appendages
      • Clinical manifestations: waxy white skin, surrounding margins of superficial partial-thickness injury
      • Full-thickness injury: entire epidermis, dermis, and subcutaneous tissue destroyed
      • Clinical manifestations: burn color is white, cherry, red, or black; blisters are rare

    Burn Shock

    • Consequences of a major burn injury, leading to a life-threatening hypovolemic shock
    • Phenomenon consisting of both hypovolemic and cardiovascular components, and cellular components
    • Capillary seal indicates the end of burn shock

    Types of Cells

    • Neuron:
      • Primary information/communication cell of the nervous system
      • Variable size and structure throughout the nervous system
      • Primary fuel is glucose, no insulin required for cellular glucose uptake in CNS
      • Cell body (soma) located mainly in the CNS
      • Dendrites carry nerve impulses toward the cell body
      • Axons carry nerve impulses away from the cell body
      • Myelin: segmented layer of lipid material, insulating substance
      • Functional classification: sensory, associational, and motor neurons

    Synapses

    • Region between adjacent neurons
    • Impulses transmitted across the synapse by chemical and electrical conduction
    • Presynaptic neurons: proximal to the synapse, relay impulses toward the synapse
    • Postsynaptic neurons: distal to the synapse, relay impulses away from the synapse
    • Neurotransmitters formed in the neuron, stored in synaptic knobs or boutons

    Central Nervous System (CNS)

    • Reticular Formation: network of connected nuclei regulating vital reflexes
    • Forebrain (telencephalon):
      • Cerebrum: largest portion of the brain
      • Cerebral cortex: gray matter, organized into columns perpendicular to the surface
      • White matter: numerous tracts, composed of myelinated nerve fibers
      • Lobes: frontal, parietal, occipital, and temporal
      • Functions: voluntary motor, sensory, and cognitive processes

    Brain Stem (Hindbrain)

    • Midbrain: relay center for motor and sensory tracts
    • Cerebellum: maintains balance and posture
    • Pons: important center for control of respiration
    • Medulla oblongata: lowest portion of the brainstem, controls reflex activities

    Cranial Nerves (Peripheral Nervous System)

    • CN I: Olfactory (sensory)- smell
    • CN II: Optic (sensory)- vision
    • CN III: Oculomotor (motor)- pupil reaction, extraocular movement
    • CN IV: Trochlear (motor)- extraocular movement, superior oblique muscles
    • CN V: Trigeminal (motor & sensory)- mastication, face sensation
    • CN VI: Abducens (motor)- EOM, lateral rectus
    • CN VII: Facial (motor & sensory)- facial expression, taste on anterior of tongue
    • CN VIII: Vestibulocochlear (sensory)- hearing
    • CN IX: Glossopharyngeal (motor & sensory)- motor fibers serve pharynx and salivary glands
    • CN X: Vagus (motor & sensory)- motor and sensory for pharynx, parasympathetic motor fiber
    • CN XI: Spinal Accessory (motor)- sternocleidomastoid and trapezius muscles
    • CN XII: Hypoglossal (motor)- tongue muscles

    Spinal Cord

    • Lies within the vertebral canal, protected by the vertebral column
    • Connects the brain and the body, conducts somatic and autonomic reflexes
    • Modulates sensory and motor function
    • Regions: cervical, thoracic, lumbar, sacral, and coccygeal
    • Conus medullaris: end of the spinal cord
    • Cauda equina: nerve bundle at the end of the spinal cord

    Upper and Lower Motor Neurons

    • Upper Motor Neurons:
      • Motor pathways completely contained within the CNS
      • Efferent pathways primarily relaying information from the cerebrum to the brainstem or spinal cord
      • Disruptions result in initial paralysis, followed by partial recovery
    • Lower Motor Neurons:
      • Neurons having direct influence on muscles
      • Cell bodies originate in the gray matter of the spinal cord
      • Destruction leads to permanent paralysis

    Meninges

    • Protective membranes surrounding the brain and spinal cord
    • Dura mater, arachnoid, and pia mater
    • Falx cerebri: dips between the two cerebral hemispheres along the longitudinal fissure
    • Form potential and real spaces important in understanding functional and pathologic mechanisms

    Blood Supply to the Brain

    • Blood supplied by two pairs of large blood vessels: carotid arteries and vertebral arteries
    • Circle of Willis: anterior, middle, and posterior cerebral arteries
    • ACA: supplies blood to the frontal lobe
    • MCA: supplies blood to the middle part of the brain
    • PCA: supplies blood to the back of the brain

    Blood Brain Barrier

    • Cellular structures that selectively inhibit certain substances from entering the brain or CSF
    • Functions: protects the brain, maintains a constant biochemical environment
    • Increases permeability or breakdowns: hypertension, dilutional hyponatremia, high doses of anesthetics, vasodilation, and hypercapnia

    Peripheral Nervous System (PNS) and Autonomic Nervous System (ANS)

    • PNS: cranial nerves and spinal nerves, peripheral nerve pathways
    • ANS: motor and sensory pathways regulating the body's internal environment
    • Somatic Nervous System: motor and sensory pathways regulating voluntary motor control of skeletal muscle
    • Autonomic Nervous System: motor and sensory pathways regulating the body's internal environment
    • Sympathetic Nervous System: mobilizes energy stores, increases HR and BP, and diverts blood from gut to skeletal muscle
    • Parasympathetic Nervous System: conserves and restores energy, promotes visceral activity and repose

    Neuroanatomy of Pain

    • Nociception: transduction, transmission, perception, and modulation
    • Primary-order neurons: nociceptors, bare nerve endings responding to chemical, mechanical, and thermal stimuli
    • Second-order neurons: interneurons in the dorsal horn of the spinal cord
    • Third-order neurons: afferent neurons in the spinothalamic tract
    • Types of pain: somatic, visceral, referred, and neuropathic pain

    Types of Acute Pain

    • Somatic pain: superficial, arises from connective tissue, muscle, bone, and skin
    • Visceral pain: internal, transmitted by sympathetic afferents, poorly localized
    • Referred pain: present in an area distant from its origin, supplied by the same spinal segment

    Chronic Pain and Neuropathic Pain

    • Chronic pain: persistent or intermittent, no physiological signs, significant behavior and psychological changes
    • Neuropathic pain: result of trauma or disease of the PNS and CNS, leads to abnormal central pain processing
    • Conditions: myofascial pain syndromes, chronic postoperative pain, low back pain, and chronic pain associated with cancer
    • Peripheral neuropathic pain: injured nerves become hyperexcitable
    • Central neuropathic pain: caused by lesion or dysfunction in brain or spinal cord
    • Clinical manifestations: paroxysmal with hyperesthesia and paresthesia, burning, shooting, or stabbing sensations### Temperature Regulation
    • Achieved through precise balancing of heat production, heat conservation, and heat loss
    • Mediated by the hypothalamus
    • Body temperature is maintained around 37°C (98.6°F)
    • Varies in response to: location, activity, environment, circadian rhythm, and gender
    • Peripheral thermoreceptors in the skin and central thermoreceptors in the hypothalamus, spinal cord, and abdominal organs provide information about skin and core temperatures

    Fever

    • Triggered by release of pyrogens from leukocytes and other cells involved in the immune response (endogenous pyrogens) and bacteria (exogenous pyrogens)
    • Both a symptom of a disease and a normal immunologic mechanism
    • Involves resetting of the hypothalamic thermostat to a higher level
    • Benefits of fever:
      • Kills many microorganisms
      • Decreases serum levels of iron, zinc, and copper needed for bacteria replication
      • Promotes lysosomal breakdown and auto-destruction of cells
      • Increases lymphocytic and phagocyte motility
      • Augments antiviral interferon production and phagocytosis

    Hyperthermia

    • Marked warming of core temperature
    • Not mediated by pyrogens
    • No resetting of the hypothalamic set point
    • Consequences:
      • 41°C (105.8°F): nerve damage produces convulsions
      • 43°C (109.4°F): death results
    • Forms of accidental hyperthermia:
      • Heat cramps
      • Heat exhaustion
      • Heatstroke (potentially lethal)
      • Malignant hyperthermia (potentially lethal)

    Sleep

    • Active, multiphase process
    • Hypothalamus is the major sleep center
    • Suprachiasmatic nucleus (SCN) controls the timing of the sleep-wake cycle
    • Hypocreatins (orexins) promote wakefulness and REM sleep
    • Two phases:
      • Rapid eye movement (REM) sleep (20% to 25% of sleep time)
      • Non-rapid eye movement (NREM) sleep (75% to 80% of sleep time)
    • Stages of NREM sleep:
      • Stage N1: light sleep (3% to 8% of sleep time)
      • Stage N2: longest sleep (45% to 55% of sleep time)
      • Stage N3: slow-wave sleep (15% to 20% of sleep time)

    Obstructive Sleep Apnea (OSAS)

    • Disorder of breathing during sleep, related to upper airway obstruction
    • Associated with reduced blood oxygen saturation and hypercapnia
    • Risk factors: obesity, male gender, and age
    • Clinical manifestations:
      • Loud snoring
      • Gasping
      • Intervals of apnea lasting 10-30 seconds
      • Fragmented sleep
      • Chronic daytime sleepiness
    • Drusen or retinal waste products accumulate in the deep retinal layers
    • An eye disease that can blur central vision
    • Happens when aging causes damage to the macula (the part of the eye that controls sharp, straight-ahead vision)
    • Two types:
      • Dry AMD (atrophic AMD): loss of retinal pigment epithelium photoreceptors with overall atrophy of cells
      • Wet AMD (neovascular AMD): abnormal blood vessels grow in the back of the eye and damage the macula

    Glaucoma

    • Intraocular pressures above the normal pressures of 12 to 20 mmHg are maintained by the aqueous fluid
    • Increased pressure that compresses and damages the optic nerve
    • Clinical manifestations:
      • Eye pain
      • Pressures
      • Headaches
      • Rainbow-colored halos around lights
      • Low vision, blurred vision, narrowed vision (tunnel vision), or blind spots
      • Nausea and vomiting

    Hearing Loss

    • Types:
      • Conductive hearing loss: impaired sound conduction from the outer to inner ear
      • Sensorineural hearing loss: impairment of the organ of corti or its central connections
      • Mixed hearing loss: combination of conductive and sensorineural losses
      • Functional hearing loss: no organic reason, thought to be caused by emotional or psychologic factors
      • Tinnitus: ringing of the ears

    Vertigo

    • Sensation of spinning that occurs with inflammation of the ear's semicircular canals
    • State of being awake
    • Mediated by the reticular-activating system

    Awareness

    • Cognitive functions that embody awareness of self, environment, and affective states (moods)
    • Content of thought

    Coma

    • No verbal response to the external environment or to any stimuli
    • Noxious stimuli such as deep pain or suctioning yields motor movement
    • Produced by either:
      • Bilateral hemisphere damage or suppression
      • Brainstem lesions or metabolic derangement that damages or suppresses the reticular activating system

    Brain Death

    • Brain has no potential for recovery and can no longer maintain the body's internal homeostasis
    • State laws: entire brain, brainstem, and cerebellum stops functioning or has already autolyzed on postmortem examination### Cerebral Edema
    • Increase in fluid (intracellular or extracellular) within the brain
    • Harmful effects cause distortion of blood vessels, displacement of brain tissues, and eventual herniation of brain tissue from one compartment to another
    • Results from infection, hemorrhage, tumor, ischemia, infarct, or hypoxia
    • Types of cerebral edema:
      • Vasogenic: most clinically important, caused by increased permeability of the capillary endothelium of the brain after injury to the vascular structure
      • Cytotoxic: metabolic, toxic factors directly affect cellular elements of the brain parenchyma, causing failure of the active transport system
      • Interstitial: seen most commonly with non-communicating hydrocephalus

    Hydrocephalus

    • Excess fluid within the cranial vault, subarachnoid space, or both
    • Caused by interference in CSF flow:
      • Decreased reabsorption: blockage of arachnoid villi (absorption) from SAH or infection
      • Increased fluid production: choroid plexus tumor
      • Obstruction within the ventricular system: tumor or congenital malformation
    • Types of hydrocephalus:
      • Communicating (extraventricular) hydrocephalus: from impaired absorption, CSF can flow through ventricles
      • Non-communicating hydrocephalus: internal or intraventricular, blockage occurs along narrow pathways that connect the ventricular system
      • Normal pressure hydrocephalus: occurs mostly in middle-aged people, long-term presentation: memory decline, gait disturbance, and incontinence

    Upper Motor Neuron Syndromes

    • Spastic paresis or paralysis:
      • Hemiparesis or hemiplegia: upper and lower extremities on one side
      • Paraparesis or paraplegia: affects lower extremities
      • Quadriparesis or quadriplegia: all 4 extremities
    • Associated with hyperreflexia, pyramidal motor syndrome
    • Spinal shock: complete cessation of spinal cord functions below the lesion, flaccid paralysis, absence of reflexes, and marked disturbances of bowel and bladder function

    Lower Motor Neuron Syndromes

    • Flaccid paresis or paralysis:
      • Caused by dysfunction of lower motor neurons (anterior horn cells and motor nuclei of the brainstem)
      • Impairs voluntary and involuntary movement
      • Degree of paralysis or paresis proportional to the number of lower motor neurons affected
      • Associated with areflexia or hyporeflexia

    Huntington Disease

    • Autosomal dominant hereditary degenerative disorder
    • Severe degeneration of the basal ganglia (caudate nucleus) and frontal cerebral atrophy
    • Clinical manifestations:
      • Abnormal movement (chorea)
      • Progressive dysfunction of intellectual processes (dementia)
      • Thought processes mark the onset of the disease
      • Choreiform movements begin in the face and arms and progresses to the rest of the body
      • Symptoms of frontal lobe dysfunction: executive attention deficits, short-term memory loss, reduced capacity to plan, organize, and sequence, bradyphrenia, and apathy
      • Euphoria and depression may be present

    Parkinson Disease

    • Degeneration of the dopaminergic pathway to the basal ganglia
    • Results in inhibition of the motor cortex, manifested with bradykinesia and rigidity
    • Hallmark pathologic features of PD: loss of dopaminergic pigmented neurons in the substantia nigra pars compacta with dopaminergic deficiency in the putamen
    • Clinical manifestations:
      • Insidious onset of symptoms
      • Classic motor manifestations: bradykinesia, tremor at rest, muscle rigidity, hypokinesia, and stooped posture
      • Non-motor symptoms: hyposmia, fatigue, pain, autonomic dysfunction, sleep fragmentation, depression, and dementia with or without psychosis

    Focal Brain Injuries

    • Contusion: bruising of the brain
    • Laceration: tearing of brain tissue
    • Extradural (epidural) hematoma: accumulation of blood above the dura mater
    • Subdural hematoma: blood between the dura mater and arachnoid membrane
    • Intracerebral hematoma: bleeding in the brain
    • Open head trauma: skull fracture with exposure of the cranial vault to the environment

    Diffuse Brain Injuries

    • Result from the effect of head rotation or shaking
    • Brain experiences shearing stresses, resulting in axonal damage
    • Pathophysiology can only be seen with a microscope
    • Oxygen free radicals contribute to secondary injury

    Concussions

    • Temporary axonal disturbance causing attention and memory deficits
    • Grade I: confusion, disorientation, and momentary amnesia, no loss of consciousness
    • Grade II: momentary confusion and retrograde amnesia, no loss of consciousness
    • Grade III: confusion with retrograde and anterograde amnesia, loss of consciousness for seconds to minutes
    • Grade IV: disconnection of cerebral systems from the brain stem and reticular activating system, loss of consciousness for more than 24 hours

    Spinal Cord Trauma

    • Most commonly occurs due to vertebral injuries
    • Traumatic injury of vertebral and neural tissues, resulting in compression, pulling, exerting tension on tissue, or shearing tissues
    • Often causes spinal shock with cessation of all motor, sensory, reflex, and autonomic functions below the transected area
    • Loss of motor and sensory function depends on the level of injury

    Cerebrovascular Accident (Stroke)

    • Thrombotic stroke: arterial occlusions caused by thrombi formed in arteries supplying the brain or in intracranial vessels
    • Embolic stroke: fragments that break from a thrombus formed outside the brain
    • Hemorrhagic stroke: bleeding into the brain, can occur secondary to TBI
    • Lacunar stroke: microinfarct smaller than 1cm in diameter, involves small perforating arteries, predominantly in the basal ganglia, internal capsules, and pons

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    Learn about the functions and characteristics of osteoblasts and osteocytes in bone formation and maintenance. Understand how osteoblasts produce osteocalcin and form new bone, while osteocytes play a role in maintaining bone health.

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