What is drug addiction and why do people become dependent on drugs? Explain why alcohol is a drug and list the health effects of smoking.

Here are the answers to your questions: 10. Drug addiction is a chronic, relapsing brain disease characterized by compulsive drug seeking and use, despite harmful consequences. It involves a physical and/or psychological dependence on a substance. 11. Four reasons why people become dependent on drugs include: Genetic predisposition: Some individuals may have a genetic vulnerability to addiction. Mental health disorders: People may use drugs to self-medicate symptoms of anxiety, depression, or other mental health conditions. Peer pressure and social influence: Desire to fit in with a social group can lead to drug use. Trauma or stress: Using drugs as a coping mechanism for past trauma or ongoing stress. 12. Alcohol is considered a drug because it is a psychoactive substance that alters the function of the central nervous system. It affects mood, perception, and behavior, and can lead to physical and psychological dependence. 13. Cigarette smoking can affect your health in many ways, including: Increased risk of lung cancer, throat cancer, and mouth cancer. Development of cardiovascular diseases like heart attack and stroke. Chronic respiratory conditions such as emphysema and chronic bronchitis. Reduced fertility in both men and women. Weakened immune system. 14. • Exocrine glands secrete substances through ducts onto an epithelial surface or into a body cavity. Example*: Salivary glands secrete saliva into the mouth; sweat glands secrete sweat onto the skin. • Endocrine glands are ductless glands that secrete hormones directly into the bloodstream. Example*: The thyroid gland secretes thyroid hormones into the blood; the pituitary gland secretes growth hormone. 15. Three differences between nervous and hormonal coordination: Speed of action: Nervous coordination is very fast (milliseconds), while hormonal coordination is generally slower (seconds to days). Duration of effect: Nervous effects are typically short-lived, whereas hormonal effects can be long-lasting. Specificity of target: Nervous responses are highly localized to specific muscles or glands, while hormones can have widespread effects on many target cells throughout the body. 16. The sequence of events in a reflex arc when the hand is withdrawn from a sharp object: 1. Receptors in the skin detect the sharp object (stimulus). 2. A sensory neuron transmits the nerve impulse from the receptor to the spinal cord. 3. In the spinal cord, a relay neuron (interneuron) processes the impulse and passes it to a motor neuron. 4. A motor neuron transmits the impulse from the spinal cord to an effector muscle in the arm. 5. The effector muscle contracts, causing the hand to be withdrawn rapidly. 17. Balance is maintained while walking through the coordinated action of several systems: The vestibular system in the inner ear detects head movements and changes in position. Proprioceptors in muscles, tendons, and joints provide information about body position and movement. Vision helps orient the body in space. The cerebellum in the brain integrates all this sensory information and sends signals to muscles to adjust posture and maintain equilibrium. 18. The causes of: a)* Long-sightedness (Hyperopia): Occurs when the eyeball is too short, or the cornea/lens is too flat, causing light rays to focus behind the retina instead of directly on it. b)* Astigmatism: Caused by an irregular curvature of the cornea or, less commonly, the lens. This uneven curvature prevents light from focusing uniformly on the retina, leading to blurred or distorted vision at all distances. 19. Sound passes from the tympanic membrane (eardrum) to the oval window as follows: 1. Sound waves cause the tympanic membrane to vibrate. 2. These vibrations are transferred to the first ossicle, the malleus (hammer), which is attached to the eardrum. 3. The malleus transmits the vibrations to the incus (anvil). 4. The incus then passes the vibrations to the stapes (stirrup). 5. The stapes, the smallest bone, vibrates against the oval window, transferring the mechanical vibrations into the fluid of the inner ear. 20. Causes for youth engaging in drug abuse include: Peer pressure: Desire to be accepted by friends who use drugs. Curiosity and experimentation: Wanting to experience the effects of drugs. Stress and emotional escape: Using drugs to cope with academic pressure, family problems, or emotional distress. Lack of parental supervision or guidance: Insufficient monitoring or guidance from adults. Media influence: Portrayals of drug use in media that may normalize or glamorize it. 21. The concentration of sugar (glucose) in blood is maintained constant in humans primarily by the hormones insulin and glucagon, produced by the pancreas: When blood glucose levels rise (e.g., after a meal), the pancreas releases insulin. Insulin promotes the uptake of glucose by cells for energy and its conversion to glycogen for storage in the liver and muscles, thus lowering blood glucose. When blood glucose levels fall (e.g., during fasting), the pancreas releases glucagon. Glucagon stimulates the liver to convert stored glycogen back into glucose and release it into the bloodstream, thereby raising blood glucose levels. This forms a negative feedback loop. 22. Comparison of functions of parts of the mammalian eye and a camera: Cornea and Lens (Eye) vs. Lens (Camera): Both focus light rays to create a sharp image. The cornea provides most of the focusing power in the eye, while the lens fine-tunes it. A camera lens performs all the focusing. Iris and Pupil (Eye) vs. Aperture (Camera): Both control the amount of light entering. The iris adjusts the size of the pupil in the eye, similar to how the aperture blades adjust the opening in a camera. Retina (Eye) vs. Film/Sensor (Camera): Both are light-sensitive surfaces where the image is formed. The retina contains photoreceptor cells that convert light into electrical signals, while film or a digital sensor records the image. Eyelids (Eye) vs. Lens Cap/Body (Camera): Eyelids protect the eye from damage and excessive light, similar to how a lens cap protects a camera lens or the camera body protects its internal components. 3 done, 2 left today. You're making progress.