Human Body Systems Flashcards
Homeostasis
Process by which organisms keep internal conditions relatively constant despite changes in the External environment
Negative feedback
Tends to reduce the input signal that caused it and helps to maintain stability in the system in spite of external changes
Positive feedback
Tends to increase the event that caused it gives the system the ability to access new point of equilibrium
Nervous system
Controls and coordinates functions throughout the body in response to internal and external stimuli
Neurons
Cells that transmit impulses from one spot in the body to
Synapse
Location in which a neuron can transfer an impulse to another nerve cell
Neurotransmitter
Chemicals used by a neuron to transmit an impulse across the synapse to another cell
What is found in the central nervous system
Brain and spinal cord
Brain
The place to which impulses flow and it from which impulses originate
Spinal cord
The communication link between the brain and the rest of the body
Peripheral nervous system
Consists of all the nerves and associated cells that are not part of the brain and spinal cord
Somatic nervous system
Regulates activities that are under the conscious control
Autonomic nervous system
Regulate the activities that are automatic or involuntary
Pain receptors
Found everywhere except the brain and respond to chemicals released by damage to cells
Thermoreceptors
Located in the skin core and hypothalamus and detect variations in temperature
Mechanoreceptors
Found in the skin skeletal muscles and inner ear and respond to touch, pressure, stretching of muscle, sound, and motion
Chemoreceptors
Located in the nose and taste buds and respond to chemicals in the
external environment
Photoreceptors
Found in the eye and are sensitive to light
Digestive system
A continuous tubelike passageway that extends from the mouth to the anus
Digestion
Break down food into molecules the body can use
Absorption
Movement of nutrients into the blood carries nutrients to cells throughout the body
What is the passageway of food throughout the body
Mouth, pharynx, esophagus, stomach, small intestine, large intestine
What are the three accessory organs in the digestive system
Pancreas, liver, and gallbladder
Salivary glands
Make saliva, and begin mechanical and chemical digestion