Patho exam 3 pt 2

Chapter 5: Infection

Key Concepts of Infection

  • Normal Flora: Refers to the microorganisms that reside in the body without causing disease under normal circumstances. They play a crucial role in maintaining health by preventing pathogenic colonization.

  • Pathogenicity: The ability of an organism to cause disease, influenced by factors such as virulence (degree of pathogenicity) and infectivity (ability to establish infection).

  • Types of Pathogens: Includes bacteria, viruses, and fungi, each with distinct characteristics and mechanisms of causing disease.

Pathogens and Disease Mechanisms

  • Communicable Diseases: Diseases that can be transmitted from one individual to another, often through direct or indirect contact. Examples include influenza and tuberculosis.

  • Universal Precautions: Guidelines to prevent the transmission of infections, emphasizing the importance of hand hygiene and the use of personal protective equipment (PPE).

  • Chain of Infection: A model illustrating how infections spread, including the infectious agent, reservoir, portal of exit, mode of transmission, portal of entry, and susceptible host.

Clinical Models of Infection

  • Acute Infection Phases: Includes five phases: incubation, prodromal, acute, decline, and convalescence, each representing a stage in the infection process.

  • Local vs Systemic Manifestations: Local manifestations are confined to a specific area (e.g., redness, swelling), while systemic manifestations affect the entire body (e.g., fever, malaise).

  • Septicemia: A severe complication of infection characterized by the presence of bacteria in the bloodstream, leading to systemic inflammatory response syndrome (SIRS).

  • Immunocompromised: Having a weakened immune system

Diagnostic Tests and Clinical Examples

  • Laboratory Tests: Common tests to detect infection include blood cultures, urinalysis, and imaging studies.

  • Clinical Models: Examples include influenza, viral hepatitis (focus on A, B, C), tuberculosis, and urinary tract infections (UTIs), each with specific pathophysiology, clinical manifestations, and treatment protocols.

  • Tables and Figures: Reference to Table 5.1 for viruses and diseases, Chain of Infection, including Figure 5.10, and Table 5.2 for diagnostic tests.

Chapter 10: Altered Neural Function

Neurons and Nervous System

  • Neurons: The basic unit of the nervous system, responsible for transmitting signals. Key components include the cell body, dendrites, and axon.

  • Afferent neurons (sensory neurons) carry information from body tissues and sensory organs toward the central nervous system (CNS). Efferent neurons (motor neurons) carry signals away from the CNS to effector organs, muscles, and glands to initiate actions.

  • Action Potential: Involves three phases: resting membrane potential, depolarization, and repolarization, crucial for neuronal communication.

  • Neuronal communication is how nerve cells, or neurons, send messages to each other to share information throughout the body. They do this using electrical signals and chemical substances called neurotransmitters, allowing us to think, move, and respond to our environment.

  • Divisions of the Nervous System: Includes the central nervous system (CNS) and peripheral nervous system (PNS), each with distinct functions.

Brain and Spinal Cord Injuries

  • Blood-Brain Barrier vs Cerebral Spinal Fluid: The blood-brain barrier protects the brain from harmful substances, while cerebrospinal fluid cushions the brain and spinal cord.

  • Traumatic Brain Injury (TBI): Risk factors include falls, vehicle accidents, and sports injuries. Symptoms can range from mild concussions to severe brain damage.

  • Spinal Cord Injury (SCI): Can lead to loss of function below the injury site, with potential complications such as autonomic dysreflexia, a complication that may occur in those with Spinal Cord Injury (SCI) above thoracic level six (T-6)

Autonomic Nervous System and Assessment

  • Autonomic Nervous System: Divided into the sympathetic (fight or flight) and parasympathetic (rest and digest) systems, each regulating different bodily functions.

  • Neuro Assessment: Involves evaluating cranial nerves and neurological function,

  • Posturing in Brain Injury: Includes decorticate (flexed posture) and decerebrate (extended posture) responses, indicating different levels of brain dysfunction.

Clinical Case Examples

  • Cerebral Palsy: A group of disorders affecting movement and muscle tone, often due to brain damage before or during birth.

  • Multiple Sclerosis: An autoimmune disease affecting the CNS, leading to a range of neurological symptoms.

  • Parkinson Disease: A progressive neurological disorder characterized by tremors, rigidity, and bradykinesia.

Chapter 12: Altered Somatic and Special Sensory Function

Somatosensory Function

  • Neuronal Organization: Neurons can be organized in layers, where first-order neurons detect signals (like touch), second-order neurons relay these signals to the brain, and third-order neurons carry the information to specific areas in the brain for processing.

  • Neurotransmission: The process by which neurons communicate, including the role of neurotransmitters and synaptic transmission.

  • Dermatomes: Areas of skin supplied by sensory fibers of a single spinal nerve root, important for diagnosing nerve injuries.

Understanding Pain

  • Definition of Pain: An unpleasant sensory and emotional experience associated with actual or potential tissue damage.

  • Types of Pain: Nociceptive pain arises from tissue injury, while neuropathic pain results from nerve damage. Neurogenic pain is a type of pain that occurs when there's damage to the nervous system, either due to injury, disease, or malfunction, it's your nervous system misfiring signals that can lead to persistent pain even when there's no injury present.

  • Pain Theories: Gate control theory suggests that our bodies have a system that can 'gate' or control the flow of pain signals to the brain, meaning not all pain is perceived the same way; for example, you might feel less pain if you're distracted. In contrast, specificity theory posits that certain pain signals are specifically dedicated to conveying intense pain, making it a direct pathway to your brain that doesn't change based on distractions.

Pain Management and Treatment

  • Classification of Pain: Pain can be classified based on duration (acute vs chronic) and origin (somatic vs visceral).

  • Treatment Approaches: Includes pharmacological (e.g., NSAIDs, opioids) and non-pharmacological methods (e.g., physical therapy, cognitive-behavioral therapy).

  • Application Questions: Understanding how to apply knowledge of pain management in clinical scenarios.

Chapter 7: Altered Cellular Proliferation and Differentiation

Cellular Mechanisms

  • Cellular Proliferation vs Differentiation: Proliferation refers to cell division, while differentiation is the process by which cells become specialized. Cancer can arise when these processes are dysregulated.

  • Causes of Cancer: Factors include genetic mutations, environmental exposures, and lifestyle choices.

  • The Initiation-Promotion-Progression Theory describes how cancer develops in three main stages: initiation, where cells are damaged and become prone to cancer; promotion, where these damaged cells start to multiply due to specific factors; and progression, where the cells grow uncontrollably, leading to cancer. Think of it like a tree: the initiation stage is like planting a seed, the promotion stage is nurturing the seed to grow, and the progression stage is the tree becoming fully grown and potentially invasive.

Cancer Classifications and Types

  • Benign vs Malignant Tumors: Benign tumors are non-cancerous and do not spread, while malignant tumors invade surrounding tissues and can metastasize.

  • Cancer Classifications: Based on the tissue of origin, including carcinomas, sarcomas, leukemias, and lymphomas.

  • Clinical Signs and Symptoms: General manifestations of cancer include unexplained weight loss, fatigue, and changes in appetite.

Cancer Treatment and Prevention

  • Treatment Modalities: Include surgery, chemotherapy, radiation therapy, and immunotherapy, each with specific indications and side effects.

  • Cancer Prevention Strategies: Emphasize lifestyle modifications such as smoking cessation, healthy diet, and regular screenings.

  • Clinical Models: Examples include lung cancer, colon cancer, brain cancer, and leukemia, each with unique pathophysiology and treatment approaches.