Nervous System Flashcards
1
Q
Functions of the NS
A
- Sensory: Sense changes through sensory receptors that deviate from homeostasis
- Motor: Responde to stimuli as sensory information comes in
- Integrative: Analyze incoming sensory information, store some aspects (higher level processing of separating info), and make decisions regarding appropriate behaviours.
2
Q
What components are part of the NS
A
- Brain
- Spinal cord
- Nerves
- Sensory receptors
3
Q
Subdivisions
A
- Central nervous system (CNS): Brain and spinal cord
- Peripheral nervous system (PNS): Sesnory receptors and nerves
4
Q
Sensory receptors
Components of the PNS
A
- Ending of neurons or separate, specialized cells that detech things like temperature, pain, etc.
5
Q
Nerve
A
- A bundle of axons and their sheaths that connects the CNS to sensory receptors, muscles, and glands
1. Cranial nerves: Originate from the brain; 12 pairs
2. Spinal nerves: Originate from the spinal cord; 31 pairs
6
Q
Ganglion
A
- Collection of neuron cell bodies outside the CNS
- The sensory information from spinal nerves have their neuron cell bodies in ganglions
7
Q
Plexus
A
- Extensive network of axons, and sometimes neuron cell bodies located outside CNS
8
Q
Divisions of the PNS
A
- Sensory (afferent): Transmits action potential from receptors to CNS
- Takes the information from external environment via sensory receptors and beings it back to the CNS for processing. - Motor (efferent): Transmits action potention from CNS t othe effectors (muscles, glands etc.)
- Somatic or autonomic pathway with further subdivisions.
9
Q
Sensory Division of PNS
A
- Gathers information form external and internal environments
1. General senses: receptors spread thorughout the body (to feel temp, pressure)
2. Special senses: Receptors in specific organs (vision, hearining etc.)
SIDE NOTE: If we look at the spinal cord, doral part carries sensory information, while the front carries motor information.
10
Q
Somatic nervous system
Motor division of PNS
A
- Part of motor division
- CNS to skeletal muscles
- Voluntary control
- Single neuron system, where just the axon is going to the targe tissue.
- Synapse at the skeletal muscle occurs at the junction of a nerve cell with another cell. Neuromuscular junction is a synapse between a neuron and skeletal muscle cell.
- Once signal oes out, a contaction occurs.
11
Q
Automonic nervous system (ANS)
A
- From the CNS to smooth muscles, cardiac muscle and certain glands
- Involuntary control
- Two neuron system: first from the CNS to the ganglion; second from the ganglion to the effector
- Further division of the ANS include symapthetic and parasympathetic
12
Q
Symapthetic
A
- Prepares body for physical activity (fight or flight)
- Increase heart rate…goes from resting to active
13
Q
Parasymapthetic
A
- Regulates resting or vegetative functions such as digestion (rest and digest)
14
Q
Enertic nervious system (ENS)
A
- Plexuses within the wall of the digestive tract.
- Can control the digestive tract independently of the CNS, but still communicate with the CNS via the ANS (parasympathetic and sympathetic neurons contribute to the plexus)
Sensory: Monitor chemical and enviornmental and stretching of wall
Motor: Contracts smooth muscle and control secretions of GI organs and endocrine walls.
15
Q
Cells of Nervous System (brief)
A
- Neurons or nerve cells receive stimuli and transmit action potential via cell bodies, denderites, and axons
- Neuroglia or glial cells are non neural cells (cannot generate action potential), they support and protect neurons