Disease Outbreaks and Respiratory Health

System Regulation

• Homeostasis maintains a constant internal environment within physiological tolerances.
• It uses both communication systems, the nervous and endocrine systems.
• Diseases arise when homeostasis is not maintained.

Negative Feedback

• Negative feedback loops use outcomes as inputs for action to maintain balance.
• Response opposes the input (change) and regulates variables around a set point.
• Examples include blood glucose levels, body temperature, and blood pH.

Vital Functions

• Blood glucose: Normal range is 75-95 mg/dL.
• Body temperature: Normal range is 36-38°C.
• Blood pH: Normal range is 7.35-7.45.
• Blood osmotic concentration varies based on body size.

Blood Sugar Regulation

• High blood sugar damages cells due to hypertonic solutions drawing water.
• Blood sugar levels are controlled by insulin and glucagon, pancreatic hormones.
• Insulin lowers blood glucose levels.
• Glucagon raises blood glucose levels.

Diabetes

• Diabetes mellitus is a metabolic disorder characterized by abnormally high blood glucose levels.
• Type 1 diabetes is caused by the body's immune system destroying insulin-producing cells, requiring insulin injections.
• Type 2 diabetes is caused by the body not responding to insulin, controlled by diet management and other factors.

Thermoregulation

• Vasodilation promotes heat loss from the blood via blood vessels.
• Sweating facilitates evaporative cooling.
• Vasoconstriction prevents heat loss and conserves heat.
• Shivering generates heat via cell respiration.
• Hair erection traps warm air around the skin.

Circadian Rhythms

• The body's physiological responses to a day-night cycle.
• Controlled by melatonin from the pineal gland.
• Melatonin secretion is light-dependent.
• Can be used to manage jet lag.

Physical Exertion

• Epinephrine (adrenaline) is a stress hormone released from the adrenal glands.
• It activates the sympathetic nervous system to prepare the body for vigorous activity.
• Increased heart rate, dilated arterioles in muscles, and increased ventilation rate are outcomes of this.

Heart Rate and Ventilation Rate

• Vigorous activity leads to increased heart rates due to increased oxygen consumption by respiring tissues.
• This causes a drop in blood pH, detected by chemoreceptors in the aorta and carotid arteries.
• The brainstem signals the diaphragm and thoracic muscles to increase ventilation rate and volume.
• Expelling excess CO2 restores blood pH to homeostasis.

Digestive Control

• Food movement is regulated by both voluntary and involuntary nerve pathways.
• The CNS controls swallowing and defecation (voluntary).
• Peristalsis involves smooth muscle contractions in the alimentary canal to move food (involuntary).

System Integration

• Interactions between organ systems create new functionalities—emergent properties.
• Coordination between systems allows for multicellular organisms to collectively perform life functions and maintain homeostasis.
• Animals use two communication systems: the nervous and endocrine systems, for coordination.

Communication

• The nervous system uses electrical impulses for rapid communication between different body organs.
• The endocrine system uses chemical messengers (hormones) for slower but more widespread communication.

Receptors

• Sensory organs contain specialized receptor cells that detect specific stimuli and generate nerve impulses.

Effectors

• Effectors are organs or cells that respond to stimuli, usually muscles or glands, triggered by nerve signals.

Nerves

• Signals are sent to and from body regions along nerves consisting of sensory and motor neurons.
• Nerves may be insulated by myelin sheaths which speeds up nerve conduction.
• The spinal cord is the body's central processing unit's connection to peripheral nerves.

Reflex Actions

• Reflexes are rapid and involuntary responses to stimuli.
• Reflexes involve the spinal cord, not the brain, for quick responses.

Brain

• The brain is an integration and coordination center for memory, emotions, and consciousness, including higher-order processing.
• Parts of the brain include: Cerebrum(predominant processing center), Cerebellum (Balance/proprioception control), and Brainstem (connecting the brain to the spinal cord).

Cerebral Hemispheres

• The two hemispheres of the cerebrum process information for opposite sides of the body.
• Left hemisphere is associated with analysis and calculations
• Right hemisphere is associated with spatial abilities.

Cerebellum

• Coordinates skeletal muscle contractions, posture, and muscle tone.
• Important for balance and proprioception (sense of body position).

Brain Stem

• Connects the cerebrum to the spinal cord.
• Regulates involuntary/unconscious functions, such as breathing and heart rate.

Endocrine System

• A network of ductless glands that release hormones into the bloodstream.
• Hormones bind to specific receptors to affect the target cells.
• Includes many glands including; pancreas, adrenal gland, thyroid gland, pineal gland, gonads (sex hormones).

Hypothalamus

• Connects the nervous and endocrine systems.
• Acts as a homeostasis control center, managing and releasing hormones to regulate body functions.

Immune System

• The immune system protects the body from pathogens.
• It comprises non-specific and specific components.
• Non-specific components form the first line of defense (physical barriers).
• Specific components respond and learn to recognize pathogens (more complex).

Pathogens

• Disease-causing agents, either cellular (living) or acellular (non-living).

Disease

• Illness with symptoms; caused by pathogens, environmental factors and genetics.

Surface Barriers

• Skin, mucous membranes, and chemical secretions protect the body from pathogen entry.

Innate Immunity

• Activated when surface barriers are breached.
• Non-specific responses, no memory, but react quickly to different pathogens.
• Phagocytic leukocytes (macrophages) are primary players.

Adaptive Immunity

• Slower response, but specific to different pathogens, with memory.
• Lymphocytes (B and T cells) are key players in adaptive immunity.
• Antibodies are proteins produced by B cells for specific target recognition.

Clotting

• Repairs damaged skin by forming a blood clot.
• A cascade of reactions involving clotting factors leads to the production of thrombin, converting fibrinogen to insoluble fibrin.
• The clot temporarily stops bleeding and is later replaced or cleared.

Antigens and Antibodies

• Antigens are molecules that stimulate an immune response.
• Antibodies are proteins produced by lymphocytes to specifically target antigens.
• Both play essential roles in the immune response.

Lymphatic System

• A vasculature system that drains excess fluid, lymph, and lymphocytes through lymph nodes (essential immune response).

B Lymphocytes

• B lymphocytes are a type of lymphocyte that produces antibodies for specific antigen targeting.

Antibody Action

• Antibodies bind to antigens and make them easier to identify for phagocytic leukocytes for destruction.
• Other mechanisms include precipitation, agglutination, and neutralization.

Secondary Immune Response

• Responds more rapidly to pathogens the body has encountered before.
• Memory cells are responsible for the faster response.

Immunodeficiency

• Occurs when the immune system is compromised or absent, making the body susceptible to opportunistic infections.

Zoonoses

• Infectious diseases transmitted from animals to humans.

Antibiotics

• Biological compounds that target prokaryotic metabolism in bacteria without harming host cells.

Vaccination and Immunization

• Vaccines use weakened pathogens to generate an immune response, leading to immunity against future exposure.
• Herd immunity protects individuals who cannot be vaccinated.

Respiratory System

• Responsible for gas exchange and supplies the body with oxygen and eliminates carbon dioxide through organs such as lungs.

Concentration Gradient

• Crucial for efficient gas exchange; gases diffuse across membranes from high to low concentration.

Respiratory Surface

• Large, thin, and moist surfaces for gases to diffuse in the respiratory system.
• Examples include; lungs, and bronchial tubes.

Lungs

• Specialized respiratory structures in mammals; facilitate gas exchange by providing a large surface area for efficient diffusion.
• Made up of alveoli, with high surface area to maximize gas exchange and surrounded by capillary networks.

Breathing Mechanism

• A mechanical process that drives respiration; influenced by atmospheric, thoracic, and abdominal pressure changes in the thorax.

Lung Capacity

• Measures lung volumes, including; total lung capacity, vital capacity, tidal volume, and residual volume.

Vascular System

• The blood circulatory system that transports materials throughout the body.
• Consists of; blood, vessels(arteries, veins, capillaries) and a heart.

Blood

• Liquid connective tissue that transports various substances throughout the body
• Consists of; blood cells(RBCs, WBCs, and platelets) and liquid plasma.

Vessels

• Arteries carry blood away from the heart under high pressure.
• Veins carry blood back to the heart under low pressure.
• Capillaries facilitate exchange of materials between tissues and the blood.
• Arteries/veins branch into smaller vessels and into the capillaries forming a network throughout the body.

Heart

• A muscular pump that drives blood circulation through the body.
• Contains four chambers: two atria and two ventricles.
• The left side pumps blood to the body (systemic circulation).
• The right side pumps blood to the lungs (pulmonary circulation).

Coronary Heart Disease

• Coronary arteries supply blood to the heart muscle.
• Narrowing/blockage of these arteries can deprive the heart muscle of oxygen leading to heart attack (myocardial infarction).

Risk Factors

• Various lifestyle factors increase the risk of blood clot formation and other cardiovascular issues such as; Hypertension, smoking, diet, obesity, sedentary lifestyles, genetic predispositions, and old age.

Membrane Potential

• The difference in electrical charge between the inside and outside of a neuron's plasma membrane.
• A resting potential (-70 mV): stable when not firing, maintained by ion pumps and channels.
• An action potential (+30 mV): rapid change in charge from resting potential, spreading through the neuron.

Synapses

• Junctions between two neurons or between a neuron and an effector (muscle or gland cell).
• An action potential triggers neurotransmitters release at presynaptic neurons, crossing onto the post-synaptic neuron receptor.

Explore factors influencing disease outbreaks in isolated communities and the globalization of trade. Understand the importance of concentration gradients and characteristics of respiratory surfaces for effective gas exchange. Examine the impact of new pathogen strains and the use of percentage difference in epidemiological data.