The Nervous system LO1-4 Flashcards
The Nervous System
Sensory functions
- receptors detect sensory input
- sensory input is sent to control centre
Integrative function
- analyses & interprets sensory input
- determines appropriate responses
- generates the motor output
that causes the response
Motor function
issues motor output to activate an effector
can be skeletal, cardiac and smooth muscles or gland secretion
General sensory receptors
Are located in the skin, skeletal muscles, tendons, joints & visceral organs and include:
thermoreceptors - detect changes in temperature
nociceptors - detect painful stimuli
mechanoreceptors:
- tactile receptors - detect touch, pressure & vibration stimuli
- baroreceptors - detect changes in blood pressure
- proprioceptors - detect changes in body position (proprioception)
Special sensory receptors
photoreceptors - detect light (vision)
chemoreceptors - detect chemicals in solution (taste & smell)
mechanoreceptors called hair cells - detect hearing & balance stimuli
CNS
- Consists of the brain and spinal cord
- Control centre à performs the function of integration
- Controls our emotions, behaviours and personality
- Performs intellectual (cognitive) functions
- Stores memories
PNS
Consists of sensory receptors and the cranial, spinal and
peripheral nerves that link all parts of the body to the CNS
- cranial nerves and their branches primarily
innervate structures of the head & neck
- spinal nerves branch to form the peripheral nerves that innervate all parts of the body below the head
Somatic Nervous System
Conveys “somatic” motor output from the CNS to the body’s skeletal muscles
Somatic motor output controls:
- voluntary skeletal muscle movements
- involuntary skeletal muscle movements = somatic reflexes
Autonomic Nervous System
Conveys “autonomic” motor output from the CNS to the body’s glands, cardiac & smooth muscles
- Autonomic motor output controls involuntary (automatic)
activities, e.g.
HR, respiration, BV, pupil diameter, digestion, urination, salivation
Sympathetic division
Controls “fight-or-flight” activities - activates body
functions that support physical activity and inhibits those that don’t, e.g.
increases heart rate, respiratory airflow, blood flow to skeletal
muscles & sweat gland activity, dilates pupils, inhibits digestive functions, inhibits urination
Parasympathetic division
Controls “rest and digest” activities à activates body functions
that conserve and restore body energy, e.g. stimulates digestive functions, urination, constricts pupils, decreases heart rate, decreases respiratory airflow
Neuroglia (“nerve glue)
Support neuron development and function
Six different types of cells which collectively nourish, protect,
insulate and structurally support neurons
Neurons
Specialised cells - perform the function of communication
- when stimulated they generate electrical signals called
graded potentials and action potentials to conduct sensory
and motor information from one part of the body to another
Dendrites
Receives information, and conveys information as GP towards the cell body
Cell body
Receives information, integrates & sends
incoming information to the axon
