Science 9 Reviewer 1st Periodic Examination PDF

**Science 9 Reviewer 1^st^ Periodic Examination** **Respiratory System Overview** - **Function:** - **Pulmonary Ventilation:** Moves oxygen into the body and removes carbon dioxide. - **Additional Functions:** Assists in smelling, producing sound, and maintaining ho...

**Science 9 Reviewer 1^st^ Periodic Examination** **Respiratory System Overview** - **Function:** - **Pulmonary Ventilation:** Moves oxygen into the body and removes carbon dioxide. - **Additional Functions:** Assists in smelling, producing sound, and maintaining homeostasis. **Breathing Mechanics** - **Inhalation:** - Diaphragm and external intercostal muscles contract. - Ribcage elevates, lung volume increases, air pressure drops, air rushes in. - **Exhalation:** - Muscles relax, lung volume decreases, air pressure rises, air is expelled. **Parts of the Respiratory System** **Upper Respiratory Tract** - **Nose and Nasal Cavity:** - **Nostrils:** External openings leading to the nasal cavity. - **Vestibule Region:** Contains epithelial cilia that trap unwanted material. - **Respiratory Region:** Warms and humidifies inhaled air. - **Olfactory Region:** Contains cells responsible for the sense of smell. - **Pharynx:** - Connects the nasal and oral cavities to the larynx and esophagus. - **Nasopharynx:** Passageway for air, posterior to the nasal cavity. - **Oropharynx:** Contains palatine tonsils, posterior to the oral cavity. - **Laryngopharynx:** Connects to the larynx and esophagus, posterior to the epiglottis. - **Larynx:** - **Function:** Keeps air passages open and produces sound. - **Epiglottis:** Prevents food from entering the windpipe. - **Vocal Folds:** Vibrate to produce sound; tension affects pitch. **Lower Respiratory Tract** - **Trachea:** - **Structure:** Tube reinforced with cartilaginous rings, provides a clear airway. - **Function:** Conducts air from the larynx to the bronchi. - **Bronchus:** - **Structure:** Branches into secondary and tertiary bronchi, leading to bronchioles. - **Function:** Delivers oxygen-rich air to the lungs and removes carbon dioxide during exhalation. - **Lungs:** - **Gas Exchange:** Takes place in the lungs between inhaled air and blood. - **Lobes:** - Right lung: Three lobes. - Left lung: Two lobes with a cardiac notch for the heart. - **Alveoli:** - **Structure:** Microscopic air sacs at the end of bronchioles. - **Function:** Site of gas exchange (oxygen and carbon dioxide). - **Surfactant:** Prevents alveolar collapse by reducing surface tension; also has antibacterial properties. **Pulmonary Ventilation Process** - **Inhalation:** Air is drawn into the lungs as the diaphragm contracts. - **Exhalation:** Air is expelled as the diaphragm relaxes. **Gas Exchange** - **Oxygen Diffusion:** Oxygen moves from alveoli to capillaries. - **Carbon Dioxide Removal:** Carbon dioxide moves from blood to alveoli for exhalation. **Importance of Surfactant** - **Prevents Collapse:** Keeps alveoli inflated by reducing surface tension. - **Prevents Infections:** Has antibacterial properties that help prevent lung infections. **Additional Functions of the Respiratory System** - **Sound Production:** The larynx and vocal cords are involved in phonation. - **Smell:** The olfactory region in the nasal cavity is responsible for the sense of smell. - **Protective Mechanisms:** Mucous and cilia trap and expel foreign particles from the respiratory tract. **Key Components of the Circulatory System** - **Heart**: A muscular organ that pumps blood throughout the body via the circulatory system. It has four chambers: two atria (upper) and two ventricles (lower). - **Blood Vessels**: Tubes through which blood flows. There are three main types: - **Arteries**: Carry oxygen-rich blood away from the heart to the body. - **Veins**: Carry deoxygenated blood back to the heart. - **Capillaries**: Tiny vessels where oxygen and nutrients are exchanged with tissues. - **Blood**: The fluid that circulates through the vessels, composed of: - **Red Blood Cells (Erythrocytes)**: Carry oxygen to tissues and remove carbon dioxide. - **White Blood Cells (Leukocytes)**: Part of the immune system; defend against infection. - **Platelets**: Cell fragments involved in blood clotting. - **Plasma**: The liquid component of blood, carrying cells, nutrients, waste products, and hormones. **Circulatory Process** - **Pulmonary Circulation**: Circulation of blood between the heart and the lungs. Deoxygenated blood is pumped from the right side of the heart to the lungs to be oxygenated, and then back to the left side of the heart. - **Systemic Circulation**: Circulation of oxygenated blood from the left side of the heart to the rest of the body and returning deoxygenated blood to the right side of the heart. **Important Concepts in the Circulatory System** - **Oxygenated Blood**: Bright red blood that is rich in oxygen, carried by arteries. - **Deoxygenated Blood**: Dark red blood that contains carbon dioxide and waste products, carried by veins. - **Hemoglobin**: A protein in red blood cells that binds to oxygen and transports it through the bloodstream. - **Capillary Exchange**: The process of oxygen, nutrients, and waste products moving between blood and tissues at the capillary level. **Functions of the Circulatory System** - **Transportation**: Carries oxygen, nutrients, hormones, and waste products to and from cells. - **Protection**: White blood cells protect the body from infection, and platelets help prevent blood loss through clotting. - **Regulation**: Maintains body temperature, pH balance, and fluid balance. **Common Diseases of the Respiratory and Circulatory Systems** **Cardiovascular Diseases** - **Congenital Heart Disease** - **Description**: An inherited disorder causing abnormal blood flow due to heart malfunction. - **Symptoms**: - Excessive sweating - Extreme tiredness and fatigue - Rapid heartbeat and breathing - Shortness of breath, chest pain - Cyanosis (blue tinge to the skin) - Clubbed fingernails - **Rheumatic Heart Disease** - **Description**: A potential consequence of rheumatic fever. - **Symptoms**: - Chest pain or swelling - Joint pain and inflammation - **High Blood Pressure (Hypertension)** - **Description**: Occurs when the force against artery walls is too high. - **Symptoms**: - Dizziness - Frequent headaches - Ringing in the ears - Palpitation - **Leukemia** - **Description**: Excessive production of abnormal white blood cells. - **Symptoms**: - Fatigue, easy bruising, bleeding gums - Paleness, headache, night sweats - Vomiting - **Anemia** - **Description**: Decrease in red blood cells due to severe hemorrhage. - **Symptoms**: - Extreme fatigue, pale skin - Weakness, shortness of breath - Chest pain, frequent infections - Headache, dizziness - **Atherosclerosis** - **Description**: Thickening or hardening of arteries due to plaque buildup. - **Risk Factors**: High cholesterol, hypertension, smoking, diabetes, obesity, inactivity, poor diet. - **Symptoms**: Chest pain, cold sweats, dizziness, heart palpitations, shortness of breath, nausea. **Respiratory Infections** - **Upper Respiratory Tract Infections** - **Common Cold** - **Description**: Viral infection affecting the nasal mucosa, pharynx, and throat. - **Symptoms**: - Rhinitis, sinusitis, pharyngitis - Headache, nasal congestion, discharge - **Influenza** - **Description**: A viral infection causing systemic symptoms and respiratory inflammation. - **Symptoms**: - Fever, chills, muscle aches - Unproductive cough, sore throat - **Treatment**: - Bed rest, fluids, warmth - Antiviral drugs and yearly vaccine **Chronic Respiratory Diseases** - **Asthma** - **Description**: A chronic lung disease causing airflow obstruction. - **Symptoms**: - Coughing, wheezing, shortness of breath, chest tightness - Triggered by pollutants, allergens, certain foods, and medications - **Laryngitis** - **Description**: Inflammation of the larynx leading to hoarse voice or loss of voice. - **Bronchitis** - **Description**: Inflammation of the main air passages to the lungs. - **Symptoms**: - Malaise, chilliness, slight fever - Sore throat, dry cough progressing to mucus production - **Pneumonia** - **Description**: Infection causing the alveoli in the lungs to fill with pus or liquid, leading to breathing difficulties. - **Symptoms**: - Fever, bluish skin, difficulty breathing - Mucus cough, mental confusion - **Treatment**: - Antibiotics like amoxicillin, fluid intake, and rest - **Emphysema** - **Description**: A chronic disease that destroys lung tissue, leading to breathing difficulties. - **Risk Factors**: Smoking, air pollution, heredity, age - **Tuberculosis (TB)** - **Description**: Caused by *Mycobacterium tuberculosis*, primarily affecting the lungs. - **Transmission**: Spread through air when an infected person coughs or sneezes. - **Symptoms**: - Persistent cough, weight loss, fever, night sweats - **Treatment**: - Long-term medication (6-12 months), critical to follow regimen to prevent drug resistance **Lung Cancer** - **Description**: Leading cause of cancer-related deaths, largely attributed to smoking. - **Symptoms**: - Fatigue, persistent cough, shortness of breath - Chest pain, loss of appetite, hemoptysis (coughing up blood) - **Diagnosis**: - Chest x-rays, CT scans, biopsy - **Treatment**: - Surgery, radiation therapy, chemotherapy, targeted therapy depending on the stage Examples: **Asthma** - **Cause:** - Chronic inflammation of the airways, often triggered by allergens or irritants. - **Signs and Symptoms:** - Wheezing - Shortness of breath - Chest tightness - Coughing, especially at night or early morning - **Treatment:** - **Quick-relief medications:** Short-acting beta agonists (e.g., albuterol) - **Long-term control medications:** Inhaled corticosteroids (e.g., fluticasone), leukotriene modifiers (e.g., montelukast) - Avoidance of triggers - Asthma action plan for self-management **Hypertension (High Blood Pressure)** - **Cause:** - Often idiopathic (unknown cause), but can be influenced by genetics, lifestyle factors (e.g., diet, exercise), and underlying conditions (e.g., kidney disease). - **Signs and Symptoms:** - Often asymptomatic - Severe cases may present with headaches, dizziness, or nosebleeds - **Treatment:** - Lifestyle modifications: Diet (e.g., DASH diet), exercise, weight management, reduced sodium intake - **Medications:** ACE inhibitors (e.g., lisinopril), ARBs (e.g., losartan), diuretics (e.g., hydrochlorothiazide) - Regular blood pressure monitoring **Pneumonia** - **Cause:** - Bacterial (e.g., Streptococcus pneumoniae), viral (e.g., influenza), fungal, or parasitic infections - Aspiration of food, liquid, or vomit into the lungs - **Signs and Symptoms:** - Cough, often producing phlegm - Fever, chills - Chest pain, especially when breathing deeply - Shortness of breath - Fatigue - **Treatment:** - Antibiotics (for bacterial pneumonia) - Antiviral medications (for viral pneumonia) - Supportive care: Rest, fluids, pain relief - Oxygen therapy if necessary GENETICS  **Allele**: A variant form of a gene. Different alleles can result in different traits, such as flower color in plants or eye color in humans.  **Dominant**: An allele that expresses its trait even when only one copy is present. It \"masks\" the effect of a recessive allele when paired together (e.g., brown eyes are dominant over blue eyes).  **Genetics**: The branch of biology that studies genes, heredity, and the variation of organisms. It explains how traits are passed from parents to offspring.  **Genotype**: The genetic makeup of an individual, referring to the combination of alleles inherited from the parents (e.g., BB, Bb, or bb for a gene controlling eye color).  **Heterozygous**: Having two different alleles for a particular gene (e.g., Bb, where one allele is dominant and the other is recessive).  **Heredity**: The passing of traits from parents to offspring through genes. It explains why children inherit certain characteristics from their parents.  **Homozygous**: Having two identical alleles for a particular gene (e.g., BB or bb). Both alleles are either dominant or recessive.  **Phenotype**: The physical expression of a genotype, or the observable characteristics of an individual (e.g., brown eyes, tall height).  **Punnett Square**: A diagram used in genetics to predict the possible genotypes of offspring from a cross between two parents. It shows the potential allele combinations and their likelihood.  **Sex Chromosomes**: Chromosomes that determine the biological sex of an individual. In humans, females typically have two X chromosomes (XX), while males have one X and one Y chromosome (XY). Please review some Punnett square.