27 results found

Search Results for: excitation

Excitation

Excitation (Science: physics, psychology) An act of irritation or stimulation or of responding to a stimulus, the addition... Read More

Chlorophyll

Why are most plants green? Have you ever had the same question? Perhaps, you’ve been told that the plants are green... Read More

Sarcolemma

Sarcolemma Definition What is the sarcolemma? It is the thin, transparent, extensible plasma membrane of the muscle cell.... Read More

Circulation

Blood Blood is composed of a liquid, plasma, and blood cells such as erythrocytes (red blood cells,) leukocytes (white... Read More

Selectively-permeable membrane

Selectively Permeable Membrane Definition We can define selectively permeable membranes as those that are selectively... Read More

Photosynthesis

Photosynthesis is a physio-chemical process carried out by photo-auto-lithotrophs by converting light energy into chemical... Read More

Sensory Systems

A sensory system is a part of the nervous system consisting of sensory receptors that receive stimuli from the internal and... Read More

Photolysis

Photolysis Definition We define photolysis as a chemical process in which chemical compounds or molecules are split into... Read More

Light-dependent reaction

Many organisms, such as green plants, convert light energy into chemical energy through the mechanism of photosynthesis. In... Read More

Respiration

Organization of the Respiratory System Each lung is composed of air sacs called alveoli - the sites of gas exchange with... Read More

Muscle

Muscle cells are specialized to generate force and movement. There are three types of muscle tissue: (1) skeletal muscle,... Read More

Neural Control Mechanisms

Nerve cells called neurons generate electric signals that pass from one end of the cell to another and release chemical... Read More

Cyclic guanosine monophosphate

Definition noun plural: cyclic guanosine monophosphates (biochemistry) A cyclic form of guanosine monophosphate (chemical... Read More

Involuntary muscle

A muscle act typically either under the control of the will or without conscious control. Muscles that can be controlled at... Read More

Depolarization

Depolarization is the removal of polarity by a process or action. It might also be used to describe how such activity leads... Read More

Axon terminal

An axon terminal is any of the button-like endings of axons through which axons make synaptic contacts with other nerve... Read More

Muscular system

Muscular System Definition What is the muscular system? The muscular system is a system that includes muscle cells and... Read More

Chlorophyll c

Definition noun A form of chlorophyll that occurs only in algae, specifically the diatoms, dinoflagellates and brown algae.... Read More

Axon hillock

Axon Hillock Definition What is axon hillock? If you are familiar with the different parts of the neuron, the axon hillock... Read More

Chronaxia

Definition noun The shortest period of time required to produce an effective electrical current such that the stimulus... Read More

Myocardium

Myocardium Definition What is the myocardium of the heart?  It is the muscular middle layer of the heart that is... Read More

Adenosine

Definition noun plural: adenosines a·den·o·sine, əˈdɛn əˌsin A purine nucleoside that has adenine bound to a... Read More

Accommodation of nerve

Accommodation of nerve (Science: anatomy, nerve) The property of a nerve by which it adjusts to a slowly increasing strength... Read More

Overshoots

overshoot 1. Generally, any initial change, in response to a sudden step change in some factor, that is greater than the... Read More

Decremental conduction

Definition noun The impaired conduction in a portion of a fiber due to progressively lessening response of the unexcited... Read More

Utilization time

utilization time The minimum duration of a stimulus of rheobasic strength that is just sufficient to produce... Read More

Human Reproduction

Terminology and Concepts Primary reproductive organs are called gonads - testes in the male and ovaries in the female.... Read More