Biology - Protection and Control Flashcards
Define Nerve Impulse - Action Potential
Each Neuron receives an impulse that is passed on to the next Neuron
where do chemical events happen?
The synapse between nerve cells
where do electrical events happen?
occurs along the axon of the neuron
How do chemical events trigger a nerve impulse?
messages are transferred across synapses by chemical changes
What are the 4 steps of Chemical change?
- Calcium gates open
- Neurotransmitter is released
- Neurotransmitter binds with receptors on the neuron
- Excitation or inhibition of the membrane occurs
Calcium Gates Open -
membrane depolarizes and calcium ions enter the cell
Define Depolarization
A change within a cell that causes a shift in electrical charge distribution causing the cell to be less negatively charged
Name 4 pathogens
- Bacteria
- Viruses
- Prions
- Fungus
Define Pathogen
A biological agent that causes diseases or illnesses in a person
Why are sweat and oil glands important?
-They produce chemicals that slow down/prevent the growth of bacteria
What enzyme is found in saliva and tears that kills bacteria?
Lysozyme
what are 3 lines of defense that the body has to protect against pathogens
- external barriers
- inflammatory system
- immune system
Are the 3 lines of defense specific or non-specific
Inflammatory Response - Non specific
Immune Response - Specific
External Barriers - Non specific
What is the difference between T - Lymphocytes and B - Lymphocytes?
T - Made in the thymus gland and react to cancerous cells or viruses
B - Made in the Spleen/bone marrow and react to bacterial pathogens
List 2 functions of the lymphatic system
- Defense against disease
- Keeping body fluids at a constant level
What is lymph?
-Tissue fluid found in lymph vessels
why are there no lymph arteries?
-Lymph only flows towards the heart and arteries take substances away from the heart
What is the function of the spleen?
-Holds onto extra blood
-Filters out and destroys bacteria
what is the role of the thymus gland?
It stores T lymphocytes until they mature and are released into the_____ (Ask Miss Brown)
What is the role of the nervous system?
Send signals from one part of the body to another
What are Neurons? why are they important
-They are a network of specialized cells in the nervous system
-They coordinate actions of animals and send signals from one part of the body to other parts
List 3 functions of glial cells
-Provide neurons with nutrients
-Insulate neurons
-Remove cellular debris when neurons die
What are 2 things that could happen if the neuron did not have a proper myelin sheath
-Signals from adjacent cells would interfere with each other
-Neural impulses would be too slow
What is Serotonin’s role?
Balances hormones that affect a person’s mood
