Chapter 1 introduction to the nervous system quiz 1 Flashcards
Central Nervous System (CNS)
– brain and spinal cord
Peripheral Nervous System (PNS) –
cranial nerves, spinal nerves, ganglia, enteric plexuses, receptors
The branch of medical science that deals with the normal functioning and disorders of the nervous system is called ______
neurology
The nervous system uses electrical signals (nerve impulses or action potentials) versus the endocrine system which uses chemical signals (hormones)
The cells that conduct these impulses are called _____ or nerve cells
neurons
sensory is always ____ the central nervous system
towards
____ - sensory receptors sense stimuli or changes inside and outside the body
Sensory Function
_______ (nerve cells) conduct impulses away from a sensory structure such as the eyes toward the central nervous system (input) (PNS)
sensory neurons
_____ - analyzes the sensory information and determines an appropriate response
Integrative Function
______- respond to sensory information (after integration) by initiating glandular secretions or muscle contractions
Motor Function
motor neurons carry impulses _____ from the central nervous system to muscles or glands (output) (PNS)
away
_____ means means nerve glue
neuroglia
_________Support and protect neurons, help to maintain proper chemical environment for nervous impulses
astrocytes (astro = star)
_______-Phagocytes, can engulf microbes or injured nerve tissue
microglia
_____ and _____
Lay down myelin around axons which act as a layer of insulation to speed up the conduction of the nerve impulse
oligodendrocytes (CNS) and Schwann cells (PNS)
Gaps in the myelin are called the ______
nodes of Ranvier
______
Produce cerebrospinal fluid (CSF) which is found in brain ventricles, central canal of the spinal cord and the subarachnoid space within the meninges
ependymal cells
Slide 11 figure 15.3 p408 quiz image no neurofibers no nissl bodies
______ are the functional cell of nervous tissue
Neurons
Both are able to produce _______ or electrical impulses in response to stimuli
action potentials
Neurons consist of what 3 things?
cell body, dendrites, axon
dendrites - short, branching, processes extending from the cell body which function to _____ impulses and conduct these impulses to the cell body
receive
axon - long cylindrical process extending from the cell body that _______ ___ ____ from the cell body to another neuron, muscle fibre or gland cell
conduct impulses away
axon (continued) - axon side branches are called ______ and axons and collaterals end by dividing into many axon terminals
axon collaterals
At the ends of the axon terminals are ______ possessing _____ which store neurotransmitters
synaptic end-bulbs, synaptic vesicles
______ are chemical substances released from axons that will affect the cell they communicate with (neuron, muscle cell or gland)
Neurotransmitters
The “contact” between two neurons or between the neuron and the effector (muscle or gland) is called a _____
synapse
_____ synapse with a muscle cell
neuromuscular junction:
______ synapse with gland cell
neuroglandular junction:
the cytoplasm of an axon is called the _____ and the the plasma membrane of the axon is called the ______
axoplasm, axolemma
_____ refers to an axon or a dendrite
Nerve fiber
a ____ is comprised of a bundle of myelinated axons in the ______ covered with connective tissue
nerve, peripheral nervous system
____ are bundles of myelinated axons in the ______ which lack a protective connective tissue covering
tracts, central nervous system
______many dendrites, one axon
multipolar
_____one dendrite and one axon
bipolar
____one process emerging from the cell body
unipolar:
Neurons communicate with other neurons via electrical signals called _______ or nerve impulses
action potentials
The _______is the voltage difference between the inside and outside of an excitable cell (neuron or muscle fiber) when the cell is not stimulated, for a neuron the value is –70 mV
resting membrane potential
The cytoplasm just inside the cell membrane is _____ charged
negatively
The extracellular fluid just outside the cell membrane _____ charged
positively
______ : Inside of plasma membrane becomes less negative due to influx of Na+. If change reaches threshold, lots more Na+ rushes into the cell and depolarization occurs
Depolarization
_____ return towards resting membrane potential. Na+ stops moving into the cell, K+ moves out, inside becomes more negative.
Repolarization:
_____: Spread from one location to another. Action potential does not move along the membrane: new action potential at each successive location. Like falling dominos.
Propagation
When the cell is sufficiently stimulated (by various means such as neurotransmitters or touch) and _____ is reached (-55 mV), an action potential is generated
threshold
oligoden means what?
cube
resting, threashold, depolarizing membrane charge
-70, -55, 30
saltatory conduction
jumping nerve impulses
_______ are chemicals that bind receptors on other neurons (dendrites) or on effectors such as muscles (skeletal, cardiac and smooth) or glands
Neurotransmitters
When a neuron communicates with another neuron via neurotransmitters, it is referred to as a ______
chemical synapse
Some neurons within the central nervous system communicate directly via ______ where the axons connect directly to dendrites via gap junctions
electrical synapses
_______ is the conscious or unconscious awareness of external or internal stimuli
Sensation
________Found on or near the body surface where they detect stimuli from the external environment; eg. visual, smell, taste, touch, pressure, vibration, temperature and pain
Exteroceptors
_______Corpuscles of touch or Meissner corpuscles located in the dermal papillae of skin
Touch Receptors
________ are dendrites surrounding hair follicle
Hair root plexuses
_______ is a long lasting sensation felt over a larger area than touch
Pressure
________ (aka lamellated corpuscles) found in subcutaneous tissues and other parts of the body
Pacinian corpuscles
______ both Meissner corpuscles and Pacinian corpuscles function in detecting vibration; results from fast, repetitive signals from Meissner and Pacinian corpuscles
Vibration
_______ we have both warm and cold receptors
Thermal sensations
______are usually free nerve endings
Nociceptors
_______are located within the body and include baroreceptors which detect stretch in smooth muscle and chemoreceptors which detect chemical changes in body fluids
Interoceptors
_______ located in muscles, tendons and joints as well as inner ear
Proprioceptors
_______detect stretch of a muscle
Muscle Spindles:
________ gives information to CNS regarding the force of contraction or tension in the muscle it is associated with
Golgi Tendon Organs
_______acceleration/deceleration of joint, pain
Joint Kinesthetic Receptors:
______stretching, touch, pressure, vibration, proprioception, hearing, equilibrium, blood pressure
mechanoreceptors -
_____ temperature receptors
thermoreceptors -
______ physical or chemical damage to tissue receptors
nociceptors
light receptors (retina of eye)
photoreceptors
_______detect chemicals in mouth, nose, body fluids such as blood
chemoreceptors
Efferent neurons are subdivided into 2 divisions
somatic motor division, autonomic division
Afferent neurons are subdivided into 3 divisions
i) somatic sensory division
ii) autonomic sensory division
iii) enteric sensory division
_______ concentration of myelinated axons; the myelin imparts a white color
White Matter -
____clusters of nerve cell bodies, dendrites, axon terminals, unmyelinated axons and/or neuroglia; greyish color due to lack of myelin and presence of Nissl Bodies (ribosomes)
Grey Matter -
_____ inner grey matter shaped like a butterfly & outer white matter
Spinal Cord
______opposite orientation; thin outer layer of grey matter & inner white region with nuclei of grey matter found in concentrations
Brain
____ are masses of cell bodies and dendrites deep within the brain
nuclei
