Human Biology: Systems and Processes

Posted on Nov 28, 2024 in Biology

Exam 2 Review

Chapter 8: Circulatory System

Arteries and Veins

Arteries carry blood away from the heart, usually carrying deoxygenated blood (except for the pulmonary artery). The largest artery is the aorta.

Veins carry blood towards the heart, usually carrying deoxygenated blood (except for the pulmonary vein). The largest vein is the vena cava.

Blood Flow Path

  1. Superior Vena Cava: Blood enters the heart from the upper body.
  2. Right Atrium: Blood flows into the right atrium.
  3. Tricuspid Valve: Blood passes through into the right ventricle.
  4. Right Ventricle: Contracts, sending blood through the pulmonary valve into the pulmonary artery.
  5. Pulmonary Valve:
  6. Pulmonary Artery:
  7. Arterioles:
  8. Pulmonary Capillaries: Gas exchange occurs.
  9. Venules:
  10. Pulmonary Veins: Oxygenated blood returns to the heart.
  11. Left Atrium: Blood enters the left atrium.
  12. Bicuspid Valve:
  13. Left Ventricle: Contracts, pumping blood through the aortic valve into the aorta.
  14. Aortic Valve:
  15. Aorta:
  16. Arteries:
  17. Capillaries:
  18. Venules:
  19. Veins:
  20. Vena Cava:

Systemic and Pulmonary Circuits

Systemic Circuit: Carries oxygenated blood from the heart to the body and returns deoxygenated blood to the heart.

  • Aorta: Distributes oxygenated blood from the left ventricle.
  • Arteries: Carry oxygenated blood to tissues and organs.
  • Arterioles: Smaller branches leading to capillaries.
  • Capillaries: Gas and nutrient exchange occurs.
  • Venules: Collect deoxygenated blood from capillaries.
  • Veins: Carry deoxygenated blood back to the heart.
  • Vena Cavae: Return deoxygenated blood to the right atrium.

Pulmonary Circuit: Carries deoxygenated blood to the lungs and returns oxygenated blood to the heart.

  • Pulmonary Arteries: Carry deoxygenated blood to the lungs.
  • Pulmonary Capillaries: Gas exchange (oxygen in, carbon dioxide out).
  • Pulmonary Veins: Return oxygenated blood to the left atrium.

Red Blood Cells (Erythrocytes)

  • Lifespan: 120 days
  • Production: Bone marrow stem cells
  • Stimulating Hormone: Erythropoietin (EPO) from kidneys

Platelets: Help clot blood.

Plasma: Mostly water, contains iron for RBC production, hemoglobin (protein) for oxygen transport, and albumin (carries waste).

Blood Disorders

  • Sickle Cell Anemia: Genetic disorder causing misshapen RBCs, clotting, and reduced oxygen transport.
  • Anemia: Insufficient red blood cells.
  • Malaria: Parasitic infection of RBCs.

Blood Clots

Good Clots: Stop bleeding (bruises, scabs).

Bad Clots: Block blood flow (thrombosis, embolism).

  • Pulmonary Embolism: Clot in the lungs.
  • Stroke: Clot in the brain.

Blood Pressure

Systolic: High pressure during ventricular contraction.

Diastolic: Low pressure during atrial/ventricular filling.

Healthy Range: 100-120/60-80 mmHg

Hypertension: High blood pressure (“silent killer”).

Hypotension: Low blood pressure.

Heart Murmur: Abnormal heartbeat.

Leading Causes of Death (US 2020)

  1. Heart Attack
  2. Cancer
  3. COVID-19
  4. Accidents/Injuries

Chapter 9: Respiratory System

Respiratory Path

  1. Nose/Nasal Cavity: Filters, warms, and humidifies air.
  2. Pharynx: Back of throat.
  3. Larynx: Voice box.
  4. Epiglottis: Covers trachea during swallowing.
  5. Trachea: Windpipe.
  6. Bronchi: Tubes into lungs.
  7. Bronchioles: Smaller branches in lungs.
  8. Alveoli: Air sacs for gas exchange.

Carbon Dioxide Transport: Primarily as bicarbonate (CO2 + H2O), also as dissolved gas or bound to hemoglobin.

Air Composition: 79% nitrogen, 21% oxygen.

Diaphragm: Muscle for breathing.

Medulla Oblongata: Monitors blood CO2 and triggers breathing.

Sleep Apnea: Breathing cessation during sleep.

Bronchitis: Bronchial infection.

Pneumonia: Infection of bronchioles and alveoli.

Asthma: Bronchiole constriction.

Tobacco/Nicotine: Major respiratory threat, constricts blood vessels, leading to lung cancer.

Chapter 10: Digestive System

Digestive Process

  1. Mouth: Chewing, saliva mixes with food (bolus), salivary amylase digests carbohydrates.
  2. Pharynx: Bolus is swallowed.
  3. Esophagus: Peristalsis moves bolus to stomach.
  4. Stomach: Gastric juices turn bolus into chyme, pepsin digests proteins, lipase digests lipids, ghrelin stimulates appetite.
  5. Small Intestine: Most digestion and absorption occur.
  • Duodenum: Receives bile from gallbladder (made by liver) and enzymes from pancreas.
  • Jejunum and Ileum: Further digestion and absorption.
Large Intestine (Colon): Water absorption.Rectum: Stores waste.Anus: Waste elimination.

Accessory Organs

  • Pancreas: Produces digestive enzymes and insulin.
  • Liver: Produces bile, stores glycogen, makes fat, secretes leptin, converts ammonia to urea, detoxifies alcohol.
  • Gallbladder: Stores bile.
  • Salivary Glands: Produce saliva.

Hormones

  • Ghrelin: Stimulates appetite (stomach).
  • Leptin: Inhibits hunger (fat tissue).
  • PYY: Decreases appetite (small intestine).

Chapter 11: Nutrition

Nutrients

Macronutrients: Proteins, fats, carbohydrates.

Micronutrients: Vitamins and minerals.

Recommended Intake: 50% fruits/vegetables, 25% grains, 25% protein/fats.

Specific Nutrients

  • Carbohydrates: Primary energy source.
  • Proteins: 20 amino acids needed.
  • Fats: Unsaturated fats are healthier.
  • Fiber: 25g/day recommended.
  • Folic Acid: Coenzyme for nucleic acid synthesis.

BMI and BMR

BMI (Body Mass Index): Weight (lbs) / Height (in)^2 * 700

BMR (Basal Metabolic Rate): Calories needed for basic functions.

Eating Disorders

  • Anorexia: Insufficient nutrient intake.
  • Bulimia: Purging after eating.

Chapter 12: Urinary System

Kidney Function

Nephron: Functional unit of kidney (1 million per kidney).

  • Bowman’s Capsule: Blood filtration.
  • Proximal Tubule: Nutrient reabsorption.
  • Loop of Henle: Water and salt reabsorption.
  • Distal Tubule: Salt reabsorption.
  • Collecting Duct: Water reabsorption.

Hormones

  • Aldosterone: Activates salt pumps.
  • ADH (Antidiuretic Hormone): Increases water reabsorption.

Urinary Tract Infections

  • UTI: Bladder infection.
  • Pyelonephritis: Kidney infection.

Chapter 13: Nervous System

Types of Neurons

  • Sensory Neurons: Receive sensory input.
  • Interneurons: Transmit signals between neurons.
  • Motor Neurons: Cause muscle/gland responses.

Neuron Structure

  • Dendrites: Receive signals.
  • Axon: Transmits signals.
  • Myelin Sheath: Insulates axon (formed by Schwann cells).
  • Terminal Buds: Release neurotransmitters.
  • Synapse: Gap between neurons.

Nervous System Divisions

  • CNS (Central Nervous System): Brain and spinal cord.
  • PNS (Peripheral Nervous System): Connects CNS to body.

Motor System Divisions

  • Somatic: Voluntary muscle control.
  • Autonomic: Involuntary muscle control.
    • Sympathetic: “Fight or flight” response.
    • Parasympathetic: “Rest and digest” response.

Neurotransmitters

  • Acetylcholine (ACh): Muscle contraction, concentration.
  • Dopamine: Pleasure, reward, motivation.
  • Serotonin: Mood, sleep, appetite.
  • GABA: Inhibitory neurotransmitter.
  • Endorphins: Pain relief.