Lesson 1 Flashcards
What is the nervous system
- Specialised network of cells in human body
* Two main functions
What are the two main functions of the NS
- Collect, process, respond to info in environment
* Coordinate working of different organs and cells in body
What are the two sub-systems of the NS
- Central Nervous System (CNS)
* Peripheral Nervous System (PNS)
What is the CNS made of
- Brain
* Spinal cord
What is the brain
• Centre of conscious awareness
• Outer layer (cerebral cortex) is highly developed
-distinguishes mental functions between humans and animals
• Two hemispheres (left and right)
What is the spinal cord
- Extension of brain
- Responsible for reflex actions (pulling hand away from hot plate)
- Passes messages between brain
• Connects nerves to PNS
-which connect to specific muscles & glands
What does the PNS do
Transmits messages via neurons between CNS
What are the two sub-systems of the PNS
- Autonomic Nervous System (ANS)
* Somatic Nervous System (SNS)
What does the ANS do
• Governs vital functions
breathing heart rate digestion sexual arousal stress responses
- Has motor pathways ONLY
- Has two components (sympathetic + parasympathetic NS)
What does the SNS do
- Controls muscle movement
- Receives info from sensory receptors
- Has sensory pathways AND motor pathways
What are the four main areas of the brain
Cerebrum
Cerebellum
Diencephalon
Brain Stem
What does the cerebrum do
- Largest part of brain
- Four lobes
- Split down the middle in two halves (left & right hemisphere)
What does the cerebellum do
- Responsible for motor skills
* Balance and coordinating muscles allowing precise movements
What does the diencephalon do
• Contains thalamus
-regulates consciousness, sleep, alertness
• Contains hypothalamus
-regulates body temperature, stress response, hunger, thirst
What does the brain stem do
Regulates breathing & heart rate
What is the sympathetic nervous system (SNS)
• Activated when person is stressed
- Heart rate and breathing increase
- Digestion stops
- Salivation reduces
- Pupils dilate
- Flow of blood diverted from surface of skins
What is the parasympathetic nervous system (PNS)
Activated when body relaxed
-conserves energy
Heart rate and breathing reduce
Digestion starts
Salivation increases
Pupils constrict
What are the similarities in the CNS
• Brain stem + spinal cord control both involuntary processes
(eg brain stems controls breathing & spinal cord controls reflexes)
What are the differences in the CNS
• Brain provides conscious awareness
-allows higher-order thinking
- Spine allows for simple reflex responses
• Brain consists of multiple regions
-responsible for diff functions
-Spinal cord has one main function
What are the similarities in the PNS
• Sympathetic nervous system and somatic nervous system respond to external stimuli
- Sympathetic NS responds
(by preparing body for fight or flight) - Somatic NS responds
(by carrying info from sensory receptors to spinal cord & brain)
What are the differences in the PNS
• ANS consists of 2 sub-components
-SNS only has one
• Somatic NS has sensory & motor pathways
-ANS only motor
• ANS controls internal organs + glands
-SNS controls muscles + movement
