Biology Chapter on Homeostasis and Plant Hormones

A key concept in the study of nervous systems, referring to the self-regulating process that maintains a stable internal environment within an organism. Its purpose is to ensure optimal conditions for survival and proper cell function.

A mechanism of homeostasis where a change in a regulated variable triggers responses that counteract the initial change, bringing the variable back to its set point. These responses are often inhibitory.

A mechanism of homeostasis that acts to amplify the initial change, enhancing the original stimulus rather than counteracting it. These responses typically amplify or accelerate a process.

The primary control center of the nervous system, responsible for receiving, processing, and integrating sensory information, generating motor commands, and facilitating complex cognitive functions.

The network of nerves that carry signals to and from the CNS, connecting the brain and spinal cord to the rest of the body. It's responsible for communication and sensory and motor control.

One of the two major divisions of the nervous system, responsible for controlling voluntary movements of skeletal muscles, allowing conscious control over bodily actions.

The division of the nervous system that controls involuntary processes of internal organs, such as heart rate, digestion, and breathing. It operates largely unconsciously.

A branch of the autonomic nervous system associated with the 'fight-or-flight' response. It prepares the body for stressful situations by increasing heart rate, dilating pupils, and diverting blood flow to muscles.

Internal, or external factors causing a change in the body's internal conditions.

Any structure that detects a change in a variable and sends a signal to the control center.

The part of the control system that receives information from the sensor and determines the appropriate response.

Muscle or gland that carries out the response to restore the variable to its set point.

The spiral organ located within the cochlea, responsible for detecting sound vibrations and transmitting this information to the brain via the auditory nerve.

Specialized receptors in the skin that respond to different types of touch, pressure, and texture.

Chemoreceptors located on the tongue that detect specific chemicals dissolved in food, leading to the sensation of taste.

Gustatory cells in taste buds release neurotransmitters when stimulated by chemicals, transmitting taste signals to the brain via nerve fibers.

The state of balance and stability within the body, maintained by various physiological processes.

Cells are surrounded by fluid, and maintaining the stability of this fluid is crucial for normal cell function.

Body temperature, fluid volume, and chemical composition are crucial factors that affect the body's stability.

Homeostasis refers to the body's ability to respond to internal and external changes to maintain a stable state, ensuring normal bodily functions.

The area in the brain that acts as the control center for body temperature regulation.

The response of the body when the temperature is below the set point. This involves shivering, vasoconstriction, and increasing metabolic rate.

The response of the body when the temperature is above the set point. This involves sweating, vasodilation, and decreasing metabolic rate.

The response of the body when the water level is critically low. This involves increasing thirst, releasing antidiuretic hormone (ADH), and constricting blood vessels.

The response of the body when the water level in the bodily fluids is too high. This involves decreasing thirst, reducing ADH release, and dilating blood vessels.

The response of the body when blood sugar levels are too high. This involves releasing insulin, which promotes glucose uptake by cells.

The response of the body when blood sugar levels are too low. This involves releasing glucagon, which stimulates the liver to release glucose into the bloodstream.

The response of the body when blood pressure is above normal. This involves releasing substances that dilate blood vessels and decrease heart rate.

The response of the body when blood pressure is below normal. This involves releasing substances that constrict blood vessels and increase heart rate.

A hormone released from the pituitary gland that signals the kidneys to reabsorb more water, resulting in less urine production.

A hormone released from the pancreas that helps lower blood sugar levels by promoting glucose uptake by cells.

A hormone released from the pancreas that helps raise blood sugar levels by stimulating the liver to release glucose into the bloodstream.

A mechanism that amplifies or accelerates a process, moving the body further away from its balanced state.

The part of a positive feedback loop that detects the initial change or stimulus. It sends information to the control center.

The component of a positive feedback loop that receives information from the sensor and determines the appropriate response, typically amplifying the initial change.

The component of a positive feedback loop that carries out the response determined by the control center, further amplifying the change.

The process of childbirth provides an example of a positive feedback mechanism. As the baby's head presses against the cervix, it triggers the release of oxytocin, which intensifies contractions. This cycle continues until the baby is born.

Positive feedback mechanisms are important for ensuring the completion of certain processes in the body, such as childbirth, blood clotting, and ovulation.

While positive feedback amplifies changes, negative feedback counteracts them, restoring the body to its balanced state. This is the more common mechanism in maintaining homeostasis.

Chemical messengers produced in small amounts by plants that influence various biological processes, such as growth, development, and flowering.

Substances that trigger a response in organisms.

The responses of plants to various factors in their environment such as light, water availability, and stress.

Physical and chemical defenses that plants have developed to deter herbivores from eating their parts.

Plants that have adapted to nutrient-poor environments by trapping and digesting small insects or mollusks.

How plants respond to environmental stimuli through the production of hormones.