Unit A - General Nervous system Flashcards
What are the four general functions of the nervous system?
- Reception - of stimuli and conduction of impulses (message) to the central nervous system (CNS)
- Interpretation of Impulses - followed by decisions
- Sorting of impulses - setting or priorities for action upon them (insignificant info is ignored while urgent info is given priority)
- Transmission - Impulses to effectors - carry out appropriate activities
What are the two different types of cells in the nervous system?
- Neurons
- Glial Cells
What are the three characteristics of neurons?
- Specialized to respond to Physical and Chemical stimuli
- Conduct electrochemical signals (impulses)
- Release chemicals that regulate various body processes
What are the five characteristics of Glial Cells?
- non-conducting cells
- Nourish neurons
- remove neuron waste
- defend against infection
- Provide a supporting framework for the nervous system tissue
What cell in the nervous system has the largest volume and is most abundant?
Glial Cells (outnumber neurons by as many as 50:1).
What do sensory neurons do?
Relay information about the environment to the CNS for processing (Eyes - light, temperature).
Where is the cell body found in a sensory neuron?
midway through the axon.
Which neuron cells are myelinated?
Sensory Neurons & Motor Neurons.
Interneurons are not myelinated
What do Interneurons do?
Integrate and interpret sensory information and connect to outgoing motor neurons.
Where are interneurons found?
In the brain and the spinal cord.
What often bridges a sensory and a motor neuron?
An interneuron.
What is the PNS?
The peripheral nervous system.
What is the CNS?
The central nervous system.
What are effectors?
Muscles/glands.
What do motor neurons do?
Relay information from the CNS to the effectors.
Which neuron is shorter in length than the rest?
Interneurons.
Which neurons are found in the PNS?
Sensory and Motor Neurons.
Which neuron(s) are found in the CNS?
Interneurons.
What is a cell body?
The main mass of the cell which contains the nucleus and organelles.
What are Dendrites?
Tubelike extensions of the cell which contains the nucleus and organelles.
What are Axons?
Single, tubelike extension which carries nerve impulses away from the cell body.
What are Glial cells (Schwann, neuroglial)?
A type of cell that surrounds a neuron and appears to nourish and protect the neuron.
What are Schwann cells?
Special glial cells surrounding the axon of many neurons; aids in the production of myelin.
What is the Myelin sheath?
- white, fatty protien around the axon
What are the Nodes of Ranvier?
Gaps between adjacent Schwann cells which may help to boost the impulse along a fibre.
What is the Neurilemma?
Specialized cells that make up the Nervous system; task is to transmit impulses between the brain and all other body parts.
What is the sensory (afferent) neuron?
Transmits impulses from receptors to the CNS.
What is the Interneuron (association)?
Transmits impulses from sensory to motor neurons or
other neurons located in the brain, spinal cord or
ganglia.
What is the Motor (efferent) Neuron?
Transmits impulses to effectors.
What is a nerve?
A bundle of hundreds to thousands of axon fibres.
Lable the reflex arc in order (7).
Starting with stimulus
- Stimulus
- Pain receptor
- sensory neuron
- Interneuron
- Spinal cord
- Motor neuron
- Effector
4 & 5 are interchangeable
Lable a neuron in order.
If in same spot go from smallest to largest
- Dendrite
- Nucleus
- Cell body
- Axon
- Myelin sheath
- Schwann cell
- Node of Ranvier
- (repeat several times)
- Axon terminal
What is positive feedback?
stiumulates the horomone production of more of itself.
(very rare) oxytocin in labour
What is negative Feedback?
Inhibit the horomone production of more of itself.
(very common) Thyroxine levels in the blood
What are endocrine glands?
Release horomones into the bloodstream.
What is Hyper-_ or Hypo-_?
Hyper-_ → EXTRA-_
Hypo-_ → LOW-_
What are the two Horomones produced in the Hypothalamus?
Oxytocin and ADH
What are the two releasing Horomones produced in the Hypothalamus?
there are more, but only two for the diploma
TRH, and GnRH
What are the different Horomones released in the pituitary gland?
G - HGH
O - Oxytocin
A - ADH
T - TSH
F - FSH
L - LH
A - ACTH
P - PRL
GOAT FLAP to remember
What is TSH?
Thyroid Stimulating Horomone → Stimulates the thyroid gland to release horomones.
what is ACTH?
Adrenocorticotropic Hormone → stimulates the adrenal gland to relase hormones.
What is hGH?
Human growth hormone → stimulates liver to relase growth factors that impact bones and muscles.
What is PRL?
Prolactin → stimulates mammary glands to produce milk
What is Oxytocin?
Stimulates uterus contraction and mammary glands
