ch 6- homeostasis Flashcards
stimulus-response model
a model that describes how a system responds to a stimulus
positive feedback system
a stimulus–response process in which the response increases the stimulus
negative feedback system
a stimulus–response process in which the response counters the stimulus
stimulus (pl. stimuli)
an event or molecule that can initiate a response
receptor
a structure that detects a signal or external change, usually a protein
modulator
location where information from receptors is sent to and compared to a set point, and where molecules altering the functioning of an effector are released. Also known as the processing centre
effector
a molecule, cell, or organ that responds to a signal and produces a response
hormone
a signalling molecule released from endocrine glands that regulates the growth or activity of target cells
response
the action of a cell, organ, or organism caused by a stimulus
transduction
the series of events that occur after the reception of a signal which results in the generation of a response
Conduction
The transfer of heat through direct physical contact between two objects with different temperatures.
Convection
The transfer of heat by the movement of a liquid or gas. Warm fluids rise, carrying heat upwards, while cooler fluids sink, creating a circulation loop.
Evaporation
The process by which a liquid changes into a gas, absorbing heat from the surrounding environment in the process. This is why sweating helps cool the body.
Radiation
The transfer of heat through electromagnetic waves. This is how heat travels from the sun to Earth and how our bodies lose heat to the environment.
Metabolism
The set of chemical reactions that take place within cells to keep the body functioning. These reactions produce energy and also generate heat.
Thermoregulation
The process by which an organism maintains a constant internal body temperature despite changes in the external environment.
Endotherm
An animal (warm-blooded) that generates most of its own body heat through metabolic processes. Examples include mammals and birds.
Ectotherm
An animal (cold-blooded) that relies primarily on the external environment to regulate its body temperature. Examples include reptiles, amphibians, and fish.
Hypothalamus
A part of the brain responsible for regulating many vital functions, including body temperature, hunger, thirst, and sleep.
Vasodilation
The widening of blood vessels, allowing more blood flow to an area. This can help to increase heat loss from the body’s surface.
Cerebral Cortex
The outer layer of the brain responsible for higher functions like thinking, memory, and sensory perception.
Arrector Pili Muscles
Tiny muscles attached to hair follicles that contract in response to cold, causing hair to stand on end (goosebumps). This traps a layer of insulating air close to the skin.
Skeletal Muscle
Voluntary muscles attached to bones that allow for movement.
Vasoconstriction
The narrowing of blood vessels, reducing blood flow to an area. This can help to conserve heat within the body.
Brown Fat
A special type of fat tissue found in some mammals that generates heat when activated in cold environments.
Glucose
A simple sugar (monosaccharide) with six carbon atoms. It is the primary source of energy for most cells in the body and comes from the food we eat.
Carbohydrate
A biomolecule made up of carbon, hydrogen, and oxygen. It is a major source of energy for the body and comes in various forms, from simple sugars (monosaccharides) to complex chains (polysaccharides).
Glucose Transporter
A specialized protein embedded in the cell membrane that allows glucose to enter cells. Different types of transporters exist for various needs.
Glycogen
A complex sugar (polysaccharide) formed from linked glucose molecules. It serves as the main storage form of glucose in the body, primarily stored in the liver and muscles.
Glycogenesis
The process by which the body converts glucose into glycogen for storage.
Glycogenolysis
The breakdown of glycogen back into glucose for energy use by the body.
Blood Plasma
The liquid portion of blood, excluding blood cells. It carries various dissolved substances throughout the body, including nutrients, hormones, and waste products.