Unit 5 Flashcards
(27 cards)
Examples of pathogens
Bacteria, viruses, prions, fungous, cancerous cells
Pathogen
Biological agent that causes disease or illness to its host.
Three lines of defends against pathogens
External barriers
Inflammatory response
Immune system
External barriers
Skin prevents pathogen from entering body
Inflammatory response
White blood cells ingest bacteria
Immune system
B and t lymphocytes recognize specific antigens on pathogens and bind to them
Purpose of lymphatic system
- Defense against disease
- keeping body fluids at constant level
Flow of lymph
Always towards heart
Lymph node
Small mass of tissue that contains lymphocytes and filters pathogens from the lymph
What are tonsils made of
Clusters of lymph tissue
What do tonsils do
Provide protection against pathogens entering the mouth and nose
Spleen
Stores certain types of lymphocytes and filters and destroys bacteria and worn out red blood cells it does not filter lymph
What is the function of the nervous system
Send signals from one part of the body to another
Function of glial cells
- provide neurons with nutrients
- insulate neurons
- remove cellular debris when neurons die
How neurons communicate
Occurs at synapses
Chemical messengers in the nervous system
- neurotransmitters occur at the synapse between neurons
- hormones occur across the blood stream
Dendrites
Receive messages
Cell body
Contains machinery keeping neuron alive
Axon
Messages away from cell body to other neurons
Myelin sheath
Prevent cells signals from interfering and to speed up production of neural impulses
Axon terminal
Forms synapse with other neurons
Excitatory
Probability that the recieving neuron will fire increases
Inhibitory
Probability that the recieving neuron will fire decreases
.
Examples of neurotransmitters
Serotonin
Sleep
Apetite
Hormones
Messengers that travel across blood stream
Secreted glands
