Body Systems and Respiration

• Body systems facilitate essential life processes like respiration, circulation, digestion, and excretion.

Respiration

• Respiration can be anaerobic, aerobic, or fermentation, depending on oxygen availability.

Anaerobic Respiration

• Occurs when the body cannot supply enough oxygen to cells for glucose breakdown.
• Results in glucose converting to lactic acid and energy.
• Lactic acid buildup causes fatigue and cramps.
• Oxygen is required to break down lactic acid into water and carbon dioxide.
• Oxygen debt refers to the amount of oxygen needed to remove lactic acid.

Aerobic Respiration

• Happens when the body provides sufficient oxygen to cells.
• Oxygen and glucose convert to carbon dioxide, water, and energy.

Fermentation

• Yeast performs fermentation in the absence of oxygen.
• Yeast consumes glucose from fruits, vegetables, and grains.
• Glucose is converted to carbon dioxide, alcohol, and energy during fermentation.

Respiratory System

• Cellular respiration is the process cells use to release energy from digested food and oxygen via aerobic respiration.
• The breathing system takes in oxygen for respiration and removes waste products like carbon dioxide.
• Inhalation and exhalation are distinct processes in breathing.

Gas Exchange at the Alveoli

• Alveoli are tiny air sacs in the lungs.
• Each air sac is called an alveolus, surrounded by capillaries.
• Gases diffuse through the thin walls of alveoli and capillaries into the bloodstream.
• Carbon dioxide is exchanged for oxygen in the capillaries through diffusion.

Circulatory System

• Transports food, gases, and waste throughout the body.
• Carries oxygenated blood and dissolved food for respiration.
• Consists of blood, blood vessels, heart, and lungs.
• Veins carry deoxygenated blood from the body to the heart and lungs.
• Arteries carry oxygenated blood from the lungs to the heart and body.
• The heart functions as a pump made of cardiac muscle.
• The heart has four chambers: two ventricles (pumping chambers) and two atria (top chambers).
• Pulmonary arteries and veins connect to the lungs; the aorta is the main artery, and the vena cava is the main vein.

Digestive System

• Includes the mouth, pharynx, esophagus, stomach, liver, gallbladder, pancreas, small intestine, large intestine, rectum, and anus.

Digestive System Parts and Functions

• Mouth: Physically breaks down food; saliva starts chemical breakdown.
• Pharynx: Opens to allow food into the esophagus.
• Esophagus: Pushes food down to the stomach.
• Stomach: Chemically breaks down food using acid.
• Liver: Produces bile (for fat breakdown) and stores glucose as glycogen.
• Gallbladder: Stores bile.
• Pancreas: Regulates blood sugar by producing insulin (lowers blood sugar) and glucagon (raises blood sugar).
• Small Intestine: Absorbs nutrients and water.
• Large Intestine: Absorbs water and ions.
• Rectum: Stores feces.
• Anus: Expels feces.

Mouth

• Teeth aid in physical digestion.
• Saliva, which contains enzymes, begins the chemical breakdown of food, softening it and forming it into a ball for easier passage to the esophagus.

Excretory System

• Organisms use chemicals for metabolism and must excrete waste, which can be toxic in high concentrations.

Eliminating Waste Products Through Kidneys and Bladder

• Organisms excrete waste products to survive.

Experimental Validity, Accuracy, Reliability

• Validity: Refers to whether the experiment measures what it intends to measure, requires one IV, five levels of IV, controlled variables, and a control test.
• Accuracy: Refers to how close the measured value is to the true value, related to the limit of reading.
• Reliability: Refers to the consistency of results from repeated experiments under similar conditions, related to the number of trials and reliability percentage.
• Reliability %: (Highest value - lowest value) / average

Control Test

• A trial conducted without the influence of the independent variable.

Aim and Stuff

• Aim: Includes the IV and DV and describes the effect, avoid pronouns.
• Format: "To determine the effect on DV as IV (increase/decrease)."
• Materials: List the equipment.

Hypothesis

• Predicts the relationship between variables.
• Format: "As the (NAME the IV) increases, then the (NAME the DV) increases/decreases."

Risk Assessment

• Identifies potential risks.

Method

• Numbered steps are in the way that experiments should be listed.
• Needs repeatability and finding values on the average.
• Five levels of independent variables.
• Explains how to control specific variables.
• Includes a control test.
• Names limit of reading.

Conclusion

• States whether the hypothesis was supported.
• Format: "In conclusion, the hypothesis was (supported/not supported/partially supported) as when IV (increased/decreases) the DV (increased/decreased). This can be seen in the results as (quote quantitative data)."

Graph

• The independent variable (IV) goes on the X-axis, and the dependent variable (DV) goes on the Y-axis.
• Include units
• Add compression lines if graph doesn't start from zero ( = )
• Fill as much of the graph as possible.
• Use column graph for non-continuous IV and line graph for continuous IV.
• Use a pencil.
• Plot line graphs with 'x' marks as points.
• Use averages to plot points.

Nervous System

Central Nervous System

• Main control center made up of the brain and spinal cord.

Peripheral Nervous System

• Consists of nerves throughout the rest of the body, divided into somatic and autonomic systems.

Somatic Nervous System

• Contains nerves carrying sensory signals from the body to the CNS and motor signals from the CNS to skeletal muscles.
• Associated with voluntary movement.

Autonomic Nervous System

• Regulates the body's internal environment, and is involuntary.
• Carries signals from internal organs to the CNS and back.
• Controls processes like digestion and heartbeat.
• Subdivided into sympathetic and parasympathetic nerve fibers.

Sympathetic Nerve Fibers

• Stimulates and mobilizes energy resources, involved in "fight or flight" responses.
• Increases heart rate, blood pressure, and sweat gland activity.

Parasympathetic Nerve Fibers

• Conserves energy resources, promoting "rest and digest" responses.
• Increases salivation and digestion, decreases heart rate.

Sensory (Afferent) Neurons

• Convert external stimuli into internal signals.
• Receive stimuli from senses (touch, taste, sight, smell, hearing).

Motor (Efferent) Neurons

• Send signals from the brain or spinal cord to effectors (e.g., muscles).
• Located in the CNS but project axons into the PNS.

External Stimuli

• Changes outside the body detected by the senses (e.g., temperature, light, danger).

Internal Stimuli

• Changes, experiences, or feelings within the body (e.g., hunger, thirst, emotions).

Neuron Parts and Functions

• Sensory Receptor: Detects external stimuli.
• Cell Body: Contains the nucleus and organelles.
• Nucleus: Contains the genetic material (DNA).
• Axon: Carries electrical impulses to the axon terminal.
• Myelin Sheath: Insulates the axon and speeds up impulse transmission.
• Dendrites: Receive signals from the environment.
• Axon Terminals: Send chemical messages to the next neuron.