Nervous System Flashcards
Neuromuscular system
Connection of the muscles to the brain and spinal cord
Kinesthetic sense
Kinesthesia is the awareness of the position and movement of the parts of the body using sensory organs, located in joints and muscles. Kinesthesia is a key component in muscle memory and hand-eye coordination.
Central nervous system (CNS)
Central nervous system consists of brain & spinal cord
Spinal Nerve
Large conduction tube made of thousands of nerve fibres. Starts in spinal cord in vertebrae of spine and branches out to rest of body through the PNS
Peripheral Nervous System (PNS)
Peripheral Nervous System consists of nerves that extend out from spinal cord transporting nerve impulses to/from CNS (power lines) and is divided into sensory and motor nervous systems
Sensory Nervous System
Sensory organs (eyes/ears/skin) receive info from outside peripheral world and send via sensory nerves back to CNS
Motor Nervous System
transmits info via nerve impulses away from CNS to move muscles & organs
Sympathetic Nervous System
Part of motor nervous system that prepares body for fight or flight / warm up stimulates this system
Parasympathetic nervous system
Part of motor nervous system that calms the body down (stretch exercise involving deep breathing stimulates this system)
Soma
The region of the neuron containing the nucleus is known as the cell body or soma. Located in spinal cord where axon comes out from body and connects to muscle /nerve fibres
Ganglia
Ganglia (nerve bulbs) located in spinal cord
Dendrites
Extension branches on soma, they RECEIVE impulses from other neurons within the spinal cord
Axon
Transmits signal from head to tail Trunk of neuron that conducts impulses from Soma away from spine towards muscle
Node of Ranvier
A notch on the Axon that allows impulse to jump quickly from one node of Ranvier to another on the axon
Saltatory Conduction
When impulses jump quickly from one node of Ranvier to another on the axon
Myelin sheath
Individual paddings of fat that cover the axon and allows quicker transmission of signal
Myelinated neurons
Myelin sheath is fat & protein covering axons
Nerve Fibres
Branch out from axon trunk and TRANSPORT impulses to muscle fibres
Neuromuscular Junction (NMJ)
The NMJ is the site where a motor neuron contacts muscle fibre
How does a muscle contract
- Neutral impulse sent from CNS to muscle fibre via motor neuron
- Impulse reaches NMJ and releases the neurotransmitter acetylcholine
- acetylcholine crosses synaptic cleft to muscle fibre which causes muscle to contract
Synaptic Cleft
Gap between nerve & muscle / pre and post synaptic membrane
Synaptic vesicle
Storage compartment for neutral transmitter acetylcholine
acetylcholine
Neutral transmitter that couriers the impulse from nerve to muscle
Cholinesterase
Enzyme that breaks down acetylcholine after it has transmitted the impulse
Reflex Arc (3 phases)
Reaction to danger/ pain
1. Pain stimulus (peripheral sensory perceives stimulus /pain & sends message to CNS)
2. CNS process info (processes pain as threat)
3. CNS Stella muscle to contract (pull away from threat)
Proprioceptors
Specialized sensory organs (eyes/ears) that receive & transmit info to CNS. These Proprioceptors are called muscle spindles and golgi tendon organs (GTO)