Responses to the environment

Questão	Responda
Environment	All livings things interact with it. It is always changing. To be able to survive and reproduce, living organisms must detect these changes and respond to them accordingly
Different stages	1. A stimulus is detected by structures or organs called RECEPTORS 2. the stimulus is relayed to COORDINATION systems, these interpret the signal and produce a responde 3. The organism responds by means of organs or structures called EFFECTORS
Internal conditions	Temperature, water content and the concentration of mineral salts and glucose in the blood
Homeostasis	The ability of an organism to maintain the internal conditions stable
Stimuli	changes that occur in an organism external and internal environment, which the organism can detect
Types of stimuli	Physical Chemical
Physical Stimuli	Light: caused by light radiation Electrical: caused by electrical phenomena. Gravitational Mechanical: changes in pressure, contact forces and vibrations Thermal: changes in temperature Magnetic
Chemical stimuli	caused by the presence of certain substances, either dissolved in air or water or a part of solids
Receptors	Structures through which living organisms detect stimuli
Classification of receptors	Interoceptors Exteroceptors Propioceptors
Interceptor	Collect information about the body's internal conditions. These respond to chemical stimuli
Exteroceptors	Also called external receptors, they provide information about the outside environment. Located on the body surface Ex: sense organs
Propioceptors	Provide information concerning body positions, the relative position of its different parts, and its state of motion.
Sense organs	Complex structures that contains receptors capable of detecting a specific type of stimulus.
Depending on the type of stimulus, receptors are classified as...	Photoreceptors Thermoreceptors Mechanoreceptors Electroreceptors Magnetoreceptors Chemoreceptors
Photoreceptors	The organs of sight Cells detect light stimuli
Thermoreceptors	Changes of temperature in the environment are detected by these. They are found in the skin of mammals and the head of some snakes.
Mechanoreceptors	Cells sensitive to touch, pressure or vibrations in the environment. They are found all over the body of animals. They also detect sound waves.
Electroreceptors	Animals such as the shark, eel and platypus have specialised organs that detect the electricity generated by the muscle movement of their prey
Magnetoreceptors	Animals that respond to the earth's magnetic fields. Ex: turtles, dolphins and the bees
Chemoreceptors	Specialised cells that detect the presence of substances in the environment, through the smell and taste of vertebrates animals.
Nociceptors	cells that detect different types of stimuli that are damaging to the organism and require and IMMEDIATE response. These receptors are linked to the pain.
Rods	Highly sensitive to changes in light intensity
Cones	Detect colors and fone details
Crypsis	Ability of living organisms to resemble their surroundings
Mimicry	ability of living organisms to closely imitate another organism
Coordination in animals	Multicellular organisms need all their cells, tissues and organs to be properly organized and coordinates
Roles	1. Perceive the stimuli 2. Interpretate the information 3. Produce a response
The nervous system	Is a set of structures and organs that receive and processes the information collected by the receptors and coordinates the actions. Formed by cells and neurons Electrical impulses with responses are immediate
Nervous system in living organisms	Plants: basic (network of neurons: nerve net) Invertebrates: organized into nerves and nerves cords Vertebrates: more complex, composed by the brain and the spinal cord and the network of nerves.
Central Nervous System (CNS)	Formed by the brain and the spinal cord Protected by the skull and the backbone
Peripheral Nervous System (PNS)	Formed by nerves Receptors -> nerves -> spinal cord -> brain -> form a response -> spinal cord -> motor nerves -> response
Neurons	Cells specialized in producing and transmiting electrical nerve impulses
Types of neurons	Sensory: detect external stimuli Motor: send responses to the CNS Relay: linked to other neurons, they produce a response
Parts of the neuron	Soma Axons Dendrites Image: Illustration Of The Main Parts Of A Neuron (binary/octet-stream)
Soma	Contains the nucleus
Axons	Neuron's extensions
Dendrites	come from the soma and connect with other neurons
Synapses	connects the axon of a neuron with another neuron
The endocrine system	Formed by endocrine glands that produces hormones Slow responses, longer lasting effects In charge of growth, development, metabolism and reproduction
Coordination in plants	Plant hormones are substances that regulate and coordinate life processes of plants
Objective of the plant hormones	To regulate processes such as growth, flowering, ripening of fruit, leaf fall and production of substances
Responses	Reactions of living organisms to stimuli, that are carried out by muscles or glands
Effectors	organs, tissues or cells that respond to stimuli
Motor responses	Movement Muscles are the effectors Ex: locomotor system
Secretory responses	Glands are the effectors ex: sweat and saliva

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Responses to the environment

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	Criado por Luciana Rosell mais de 2 anos atrás