Help
Options
Didn't know it?
click below
click below
Knew it?
click below
click below
Don't Know
Remaining cards (0)
Know
retry
shuffle
restart
0:00
Embed Code - If you would like this activity on your web page, copy the script below and paste it into your web page.
Normal Size Small Size show me how
Normal Size Small Size show me how
Bio
Exam 4
| Question | Answer |
|---|---|
| What is gas exchange? | The interchange of O₂ and CO₂ between an organism and its environment, providing O₂ for cellular respiration and removing CO₂. |
| What are the three main phases of gas exchange in humans? | (1) Breathing, (2) transport of gases by the circulatory system, and (3) exchange of gases with body cells. |
| What happens during the third phase of gas exchange? | Body tissues take up oxygen from the blood and release Carbon dioxide into the blood. |
| What must respiratory surfaces be like for gas exchange to occur? | They must be thin and moist for diffusion of Oxygen and carbon dioxide. |
| What are the four types of respiratory surfaces found in animals? | Skin, gills, tracheal systems, and lungs. |
| What types of animals use their skin as a gas exchange organ? | Some amphibians and earthworms. |
| How do gills function in aquatic animals? | Gills absorb dissolved Oxygen in water and release Carbon dioxide; gas exchange is enhanced by ventilation and countercurrent exchange. |
| What is countercurrent exchange in fish? | The transfer of oxygen between water and blood flowing in opposite directions, maximizing Oxygen absorption. |
| Why is breathing air easier than gas exchange in water? | Air contains a higher concentration of Oxygen and is lighter and easier to move than water. |
| How does the tracheal system in insects work? | Air enters through openings into branching tubes (tracheae) that deliver O₂ directly to cells and remove CO₂, minimizing water loss. |
| Why was the evolution of lungs important for vertebrates moving onto land? | It enabled air breathing, supporting life on land along with skeletal changes like the development of legs from fins. |
| What fossil shows evidence of this transition? | Tiktaalik, an air-breathing fish with skeletal adaptations for movement on land. |
| What muscle separates the thoracic and abdominal cavities and helps with ventilation? | The diaphragm. |
| Describe the path of air through the human respiratory system. | Air enters the nasal cavity → pharynx → larynx → trachea → bronchi → bronchioles → alveoli. |
| What is the function of surfactant in alveoli? | It prevents alveolar surfaces from sticking together. |
| What protects the lungs from debris and pathogens? | Mucus traps particles, and cilia move them out of the respiratory passages. |
| How does smoking affect the respiratory system? | It damages cilia, causes lung cancer, and leads to diseases like COPD and emphysema. |
| What type of breathing do humans use? | Negative pressure breathing — air is pulled into the lungs as the thoracic cavity expands. |
| How does the diaphragm move during inhalation and exhalation? | Contracts and moves down during inhalation; relaxes and moves up during exhalation. |
| What controls the rate and depth of breathing? | Breathing control centers in the medulla oblongata respond to CO₂ levels and pH in cerebrospinal fluid. |
| What happens when blood CO₂ levels rise? | pH drops, triggering the medulla to increase breathing rate and depth. |
| How does blood transport respiratory gases? | The heart pumps oxygen-poor blood to the lungs for O₂ pickup and CO₂ release, then sends oxygen-rich blood to tissues. |
| What is partial pressure? | The portion of total gas pressure contributed by one gas in a mixture; gases diffuse from higher to lower partial pressures. |
| What is hemoglobin and its function? | An iron-containing protein in red blood cells that carries O₂, helps transport CO₂, and buffers blood pH. |
| How does hemoglobin aid in CO₂ transport? | It binds some CO₂ and helps convert the rest to bicarbonate ions for transport in plasma. |
| How does fetal hemoglobin differ from adult hemoglobin? | It has a higher affinity for O₂, allowing oxygen transfer from maternal blood in the placenta. |
| What triggers the first breath at birth? | Rising CO₂ levels in fetal blood stimulate the breathing control center. |
| What are the three main functions of the respiratory system? | Supply Oxygen and remove Carbon dioxide from the blood, and regulate blood pH. |
| How are the circulatory and respiratory systems connected? | The circulatory system transports gases between lungs and body tissues. |
| What happens when someone quits smoking? | Protective cells can repair damage, reducing future lung cancer risk. |
| What is the main function of a circulatory system? | The circulatory system facilitates exchange with all body tissues by acquiring nutrients, exchanging gases, and disposing of waste products. |
| What are the three basic components of a true circulatory system? | A muscular pump (the heart), a circulatory fluid (blood), and a set of tubes (vessels) to carry the fluid. |
| How do cnidarians and flatworms circulate materials? | They rely on a gastrovascular cavity that allows direct exchange of materials between the environment and body cells. |
| What is an open circulatory system? | A system where blood is pumped by a tubular heart through open-ended vessels, directly bathing cells in fluid that also acts as interstitial fluid; found in arthropods and most molluscs. |
| What is a closed circulatory system? | A system in which blood remains enclosed in vessels, distinct from interstitial fluid, as seen in vertebrates, earthworms, squids, and octopuses. |
| What are the three main types of blood vessels in a closed circulatory system? | Arteries carry blood away from the heart, veins return blood to the heart, and capillaries exchange materials between blood and tissues. |
| Describe the cardiovascular system of a fish. | Fish have a two-chambered heart (one atrium, one ventricle) and a single circulation system where blood passes once through the heart in each circuit of the body. |
| What is single circulation? | A circulation pattern, found in fish, where blood flows from the heart to the gills, then to the body, and back to the heart in one continuous loop. |
| How do vertebrate cardiovascular systems reflect evolution? | Land vertebrates developed double circulation, where blood is pumped a second time after losing pressure in the lungs, improving efficiency. |
| What are the two main circuits in double circulation? | The pulmonary circuit (between heart and lungs) and the systemic circuit (between heart and the rest of the body). |
| How is amphibian circulation different from fish? | Frogs have a three-chambered heart with two atria and one ventricle, where some oxygen-poor and oxygen-rich blood mix, but a ridge minimizes this mixing. |
| How does the reptilian heart differ from that of amphibians? | Turtles, snakes, and lizards have a partially divided ventricle to reduce mixing of blood, while crocodilians have a completely divided ventricle. |
| What is unique about the mammalian and avian heart? | Birds and mammals have a four-chambered heart that completely separates oxygen-rich and oxygen-poor blood, providing efficient double circulation. |
| Trace the path of blood through the human cardiovascular system. | Blood enters the right atrium via venae cavae, passes to the right ventricle, travels through the pulmonary artery to the lungs, returns via pulmonary veins to the left atrium, then exits the left ventricle through the aorta to the body. |
| What are the main features of the human heart? | The heart is about the size of a fist, composed of cardiac muscle, enclosed under the sternum, and contains valves to ensure one-way flow of blood. |
| What is the cardiac cycle? | The rhythmic sequence of heart contraction (systole) and relaxation (diastole) that pumps blood throughout the body. |
| What happens during diastole? | The heart relaxes, allowing blood to flow from veins into the heart chambers. |
| What happens during systole? | The atria and ventricles contract, pushing blood first into ventricles and then out of the heart into arteries. |
| What is cardiac output? | The volume of blood each ventricle pumps per minute, determined by heart rate and stroke volume. |
| What does the SA node do? | The sinoatrial (SA) node acts as the pacemaker of the heart, generating electrical impulses that trigger atrial contractions. |
| What is the role of the AV node? | The atrioventricular (AV) node relays the impulse from the atria to the ventricles, triggering ventricular contraction. |
| What is an electrocardiogram (ECG)? | A test that records the electrical impulses of the heart and provides data about heart health and rhythm. |
| What is an artificial pacemaker? | A medical device implanted in the chest that emits electrical signals to regulate heartbeat when the natural pacing system fails. |
| What causes a heart attack? | A blockage of a coronary artery that prevents oxygen from reaching cardiac muscle, causing tissue death or damage. |
| What is cardiovascular disease? | A general term for disorders of the heart and blood vessels, including atherosclerosis, heart attacks, and strokes. |
| What is atherosclerosis? | A condition where fatty deposits (plaques) build up on arterial walls, narrowing arteries and restricting blood flow. |
| How are inflammation and atherosclerosis related? | Injury to artery walls triggers inflammation, which can promote plaque buildup and clot formation, increasing risk of heart attack. |
| What is a stroke? | The death of brain tissue due to lack of oxygen, usually caused by a blockage or rupture of arteries in the brain. |
| What are capillaries and their function? | Capillaries are the smallest blood vessels with thin epithelial walls that allow gas and nutrient exchange with interstitial fluid. |
| How do arteries and veins differ structurally? | Arteries have thick smooth muscle and elastic tissue for high-pressure flow, while veins have thinner walls and valves to prevent backflow. |
| What is blood pressure? | The force exerted by blood on vessel walls; it depends on cardiac output and vessel resistance and decreases with distance from the heart. |
| What are systolic and diastolic pressures? | Systolic pressure is the peak during ventricular contraction; diastolic pressure is the minimum between contractions. |
| How does blood travel upward in veins against gravity? | Muscle contractions squeeze veins, and one-way valves prevent backflow, ensuring blood moves toward the heart. |
| What is a typical blood pressure reading for a healthy adult? | About 120/70 mm Hg, with 120 being systolic and 70 being diastolic pressure. |
| What is hypertension? | Persistent high blood pressure (140/90 or above) that increases risk of heart disease, stroke, and kidney failure. |
| How does smooth muscle control blood distribution? | Arteriole smooth muscles contract or relax to regulate blood flow and pressure, aided by precapillary sphincters. |
| How do substances move through capillary walls? | By diffusion, vesicle transport, and pressure-driven flow through small clefts between epithelial cells. |
| What forces drive fluid movement in capillaries? | Blood pressure pushes fluid out at the arterial end; osmotic pressure draws fluid in at the venous end; excess fluid enters lymphatic vessels. |
| What are the main components of blood? | Plasma (liquid component) and cellular elements: red blood cells, white blood cells, and platelets. |
| What is plasma? | The liquid portion of blood (about 90% water) containing nutrients, ions, gases, proteins, hormones, and waste products. |
| What are red blood cells (erythrocytes)? | Cells containing hemoglobin that transport oxygen and help carry carbon dioxide; make up most of the cellular elements in blood. |
| What are white blood cells (leukocytes)? | Immune cells that defend the body; include phagocytes such as monocytes and neutrophils that engulf bacteria and debris. |
| What are platelets? | Cell fragments that function in blood clotting by forming plugs and initiating clotting reactions. |
| What is anemia? | A condition caused by not enough red blood cells or insufficient hemoglobin, leading to fatigue from oxygen deficiency. |
| What hormone regulates red blood cell production? | Erythropoietin (EPO), produced by the kidneys, stimulates bone marrow to make more red blood cells. |
| What is blood doping? | A practice where athletes increase red blood cell count (through EPO or reinfusion) to boost oxygen delivery, which can cause dangerous clots. |
| Describe the process of blood clotting. | When a vessel is damaged, platelets adhere to exposed tissue, release chemicals, form a plug, and trigger reactions converting fibrinogen to fibrin, forming a reinforced clot. |
| What are stem cells and their role in blood formation? | Undifferentiated cells in bone marrow that produce all types of blood cells, maintaining blood cell balance. |
| What are lymphoid and myeloid stem cells? | Lymphoid stem cells produce lymphocytes for immunity; myeloid stem cells produce red blood cells, platelets, and other white blood cells. |
| What is leukemia? | A cancer of white blood cells that results in nonfunctional leukocytes, crowding out healthy cells; treated with chemotherapy, radiation, or bone marrow transplant. |
| How does anorexia affect the heart? | It weakens heart muscles, slows heart rate, lowers blood pressure, and increases risk of heart failure due to poor nutrition and muscle deterioration. |
Created by:
user-2000883