UNIT1-BIOLOGICAL ASPECTS-NERVOUS SYSTEM Flashcards
What is the main function of the nervous system?
To relay messages through sensory nerves and enable the performance of tasks.
What are the two main parts of the human nervous system?
- Central Nervous System (CNS)
- Peripheral Nervous System (PNS)
What does the Central Nervous System (CNS) consist of?
The brain and spinal cord.
What does the Peripheral Nervous System (PNS) consist of?
All the nerves that exit the brain and spinal cord.
What is the role of the somatic nervous system?
Conveys messages from sense organs to the CNS and from the CNS to the muscles.
What does the autonomic nervous system (ANS) control?
- Heart
- Intestines
- Other organs
What are the two divisions of the autonomic nervous system?
- Sympathetic nervous system
- Parasympathetic nervous system
What response does the sympathetic nervous system activate?
Fight or flight response.
What are typical sympathetic responses?
- Dilation of pupils
- Constriction of peripheral arteries
- Secretion of epinephrine
- Reduction of stomach activity
What functions does the parasympathetic nervous system control?
- Rest
- Enjoyment
- Eating
- Sleep
- Sexual activity
What are the two types of cells in the nervous system?
- Neurons
- Glia
What is the primary function of neurons?
To process and transmit information.
What role do glial cells play in the nervous system?
Support functions for neurons.
How many neurons are in the adult human brain?
Approximately 86 million.
How many glial cells are in the adult human brain?
About 360 billion.
What are the main components of a neuron?
- Soma (cell body)
- Dendrites
- Axon
- Presynaptic terminals
What is the function of dendrites?
To receive information from other neurons.
What is the role of the axon?
To convey impulses towards other neurons, organs, or muscles.
What is the myelin sheath?
An insulating material that covers many vertebrate axons.
What are afferent and efferent axons?
- Afferent axon: Brings information into a structure
- Efferent axon: Carries information away from a structure
What are the four types of macroglia?
- Astrocytes
- Ependymal cells
- Oligodendrocytes
- Schwann cells
What is the function of astrocytes?
Provide structural support and nutrients to neurons and protect the blood-brain barrier.
What do ependymal cells do?
Line brain ventricles and the spinal canal, facilitate cerebro-spinal fluid movement.
What do oligodendrocytes and Schwann cells do?
Build myelin sheaths around axons.
What is the role of microglia?
Act as part of the immune system, removing viruses and damaged neurons.
Fill in the blank: The space separating pre-synaptic and post-synaptic membranes is known as the _______.
synaptic cleft.
