Created by Luciana Rosell
over 2 years ago
|
||
Question | Answer |
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 |
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 |
Want to create your own Flashcards for free with GoConqr? Learn more.