Interaction Processes
A physical or chemical change in the environment (internal or external) that can trigger a response in an organism is called a ___.
Stimulus.
The basic cells of the nervous system that transmit nerve impulses are called ___.
Neurons.
These chemical messengers, produced by endocrine glands and carried in the bloodstream, act on target organs to elicit responses.
Hormones.
Eyes, ears, nose, tongue, and skin are examples of these organs that detect stimuli in our environment.
Sensory Organs (Sense Organs).
The locomotor system is made up of these two main components that work together to allow movement.
Skeletal and muscular systems (bones and muscles).
In a stimulus–response pathway, muscles or glands that carry out the response (like moving a limb or releasing a hormone) are collectively called ___.
Effectors
The brain and spinal cord together make up this part of the nervous system.
The Central Nervous System (CNS).
Known as the "master gland," this gland at the base of the brain secretes hormones that control many other endocrine glands.
Pituitary gland.
Specialized cells or nerve endings that detect specific stimuli (like light, sound, or chemicals) are called these.
Sensory receptors.
A place where two bones meet (often allowing movement) is known as a ___.
Joint.
The process by which an organism maintains a stable internal environment (such as constant body temperature or blood sugar levels) is called ___.
Pulling your hand away from a hot stove without thinking is an example of this rapid, automatic response.
A reflex.
During a frightening or stressful situation, the adrenal glands release this hormone (also called epinephrine) to trigger the "fight or flight" response.
Adrenaline.
In the human eye, rod and cone cells are photoreceptors located in this light-sensitive layer at the back of the eye.
The retina.
These tough, fibrous tissues connect muscles to bones, allowing bones to move when muscles contract.
Tendons.
High blood sugar triggers insulin release, which lowers sugar levels and reduces further insulin production. This self-correcting regulation is an example of this type of feedback mechanism.
Negative feedback.
The tiny gap between two neurons, across which chemical neurotransmitters carry the signal, is called a ___.
Synapse.
This endocrine gland in the neck controls the body's metabolism by producing the hormone thyroxine.
The thyroid gland.
This thin membrane in the ear vibrates when sound waves hit it, transmitting sound into the middle ear.
The eardrum (tympanic membrane).
The name of the longer muscles that control movements of the body (ie. your biceps and triceps).
Fusiform muscles (long muscles).
Prolonged exposure to extreme cold can cause the body’s core temperature to drop dangerously low. This life-threatening failure of homeostasis is called ___.
Hypothermia.
This disease of the nervous system leads to tremors, muscle stiffness, and difficulty moving, and is linked to low levels of the neurotransmitter dopamine.
Parkinson's disease.
This common endocrine disorder results from the pancreas not producing enough insulin, leading to high blood sugar levels.
Diabetes.
In this common vision disorder, a person can see nearby objects clearly but distant objects appear blurry due to an elongated eyeball.
Nearsightedness (myopia).
This disease causes bones to become weak and brittle, often affecting older adults as bone density is lost.
Osteoporosis.