Review of the 5 Human Senses

SightSoundTouchTasteSmell

Regulation Our environment, both inside and

outside our body, is constantly changing. Regulation is the life process by which cells and organisms respond to changes within and around them.

The control and coordination of all of the activities of an organism is known as REGULATION

In humans, regulation is carried out by the nervous system and the endocrine system. These two systems allow us to adjust to internal as well as external environmental changes, which enables us to maintain ________________

Regulation by an organism begins when the organism encounters a _______________________

A STIMULUS is a change in the environment that causes a change or activity in an organism

The action resulting from a stimulus is called a RESPONSE

The _________is carried out by a type of cell known as an effector cell

A STIMULUS is a change in the environment that causes a change or activity in an organism

The action resulting from a stimulus is called a RESPONSE

The stimulus is perceived by a receptor, which is a specialized nerve tissue which is sensitive to the stimulus

A receptor can be the ends of a dendrite, such as for touch and temperature, or specialized tissues such as the eye or ear

The neuron or nerve cell is the basic unit of the nervous systemIt is composed of three parts: 1) The cyton or soma 2) Axon 3)Terminal branches

A nerve impulse carries the signal from the receptor to the effector cell

A nerve impulse is an electrical signal that travels along a nerve fiber.

The nerve impulse is an electrochemical transmission of the nerve signal along the length of the neuron. A stronger stimulus will not produce a larger nerve impulse, but will produce more impulses in a given time period

The effector cell is the cell that performs the action specified by the nerve impulse. In humans, effector cells are either muscle cells which contract, or glands which secrete.

Once the stimulus is perceived by the receptor, a nerve impulse travels along the axon to the ends of the terminal branches. There is a small gap between the terminal branches and the next cell. This gap is called a SYNAPSE

The nerve impulse crosses the synapse through the action of special chemical messengers released by the terminal branches of the sensory neuron and received by another neuron

The sensory neuron will lead to either another sensory neuron, the brain, or an interneuron cell within the spinal cord. An interneuron cell in the spinal cord can transmit the nerve impulse either to the brain or to a motor neuron. A motor neuron will carry the signal away from the spinal cord and toward an effector cell.