Test 4 Flashcards
What two systems work together to maintain HOMEOSTASIS against internal and external changes?
Endocrine and Nervous
What does the nervous system allow us to do?
Reason, conceptualize, and integrate information
nervous system is to ______ and the endocrine system is to ______
neurotransmitters, hormones
Functions of the nervous system include….
internal/external changes in the body, integrate, analyze, and store information within the central nervous system
What’s the path from sensory receptor to the effector?
Sensory input > integration > motor output
What does the Central Nervous System include?
Brain and spinal cord
What does the peripheral nervous system include ?
All nervous tissue outside the CNS
Sensory =
afferent
Motor =
efferent
Sensory impulses send impulses (in/out)
in
motor neurons send impulses (in/out)
out
Somatic Motor Division of the Nervous System
- Neurons carry impulses from the brain
- Connect ONLY with skeletal muscle
- Stimulate muscle contractions
- Voluntary
Autonomic Motor Division of the Nervous System
- Neurons carry impulses from the brain
- Connect with cardiac muscle, smooth muscle, and glands
- Stimulate or inhibit
- Automatic (involuntary)
Sympathetic Nervous System
Fight or Flight
Parasympathetic Nervous System
Rest or Digest
Characteristics of nervous tissue
- Conducts impulses
- Consists of two main cell types: neurons and neuroglia cells
- Usually have star-like appearance
Neuroglia
- Cannot transmit impulses
- Can protects repair, regulate and aid neurons and neuronal impulse transmission
- Can divide
- Vary in shape and function
Most brain tumors are due to…
neuroglia
Which neuroglia cells are found in the peripheral system?
Satellite cells and Schwann cells
Satellite cells
Surrounds neurons cell bodies in ganglia; regulate O2, CO2, nutrient, and neurotransmitter levels around neurons in ganglia
Schwann cells
Surrounds all axons in PNS; responsible for myelination of peripheral axons; participate in repair process after injury; forms MYELIN SHEATH in PNS
Oligocendrocytes
Myelinate CNS axons, provide structural framework, forms MYELIN SHEATH in CNS
Astrocytes
Maintain blood-brain barrier; provide structural support; regulate ion, nutrient, and dissolved-gas concentrations; absorb and recycle neurotransmitters; form scar tissue after injury
Microglia
Remove cell debris, wastes, and pathogens by phagocytosis
Ependymal cells
Line ventricles and central canal; assist in producing, circulating, and monitoring cerebrospinal fluid
The central nervous system contains
Oligodendrocytes, astrocytes, and microglia
Myelinations makes fibers appear…
white
Myelination speeds up the…
rate of impulse conduction
Characteristics of neurons
- Transmits impulses
- Highly sensitive to external changes
- High metabolic rate
- Cannot divide
- Show extreme longevity (100+ yrs)
- Appear gray
- Vary in size
Dendrite of neuron
Receptive region sometime forming free nerve receptors
Soma of neuron
cell body, has nucleus and nucleolus
Axon of neuron
- Transmitting fiber
* May be myelinated or un-myelinated
White matter
Primarily myelinated fibers
Gray matter
Primarily neuron cell bodies and un-myelinated neurons
Synaptic terminal
Forms synapse
Releases neurotransmitter
Pathway of neuron transmission
Dendrites > cell body > axon > terminal boutons
bipolar neurons are in charge of …
special senses
pseudounipolar neurons are in charge of …
sensory impulses
multipolar neurons are in charge of …
motor neurons
Neurons can be organized into smaller organized groups called…
neuronal pools
Neuronal pools are identified by…
neural circuit
Examples of neural circuit
Divergence, convergence, serial processing, parallel processing, reverberation
Divergence
A circuit spreading stimulation to multiple neurons or neuronal pools in the CNS
Convergence
a circuit providing input to a single neuron from multiple sources
Serial processing
a circuit in which neurons or pools work sequentially
Parallel processing
a circuit in which neurons or pools process the same information simultaneously
Reverberation
a positive feedback circuit
Reverberation
A positive feedback circuit
Nerves…
- contain neuron fibers
* Found in bundles
Forebrain =
prosencephalon
Midbrain =
mesencephalon
Hindbrain =
rhombencephalon
Forebrain contains which regions?
Telencephalon and Diencephalon
Midbrain contains which region?
mesencephalon
Hindbrain contains which brain regions?
Metencephalon and Myelencephalon
the telencephalon contains which main brain structure?
cerebrum
Diencephalon contains which main brain structures?
Thalamus and Hypothalamus
Mesencephalon contains which main brain structures?
Cerebral peduncle and corpora quadrigemina
Metencephalon contains which main brain structures?
pons and cerebellum
Myelencephalon contains which brain structures?
medulla oblongata
Dura mater
- tough superficial layer
- not attached to bone in spinal cavity
- has two layers: endosteal layer (attached to cranium) and meningeal layer (deep)
Arachnoid layer
• cerebral spinal fluid found within sub-arachnoid space
Pia mater
• directly attached to brain and spinal cord
cranial meninges
surrounds the brain and the spinal cord
What are the three layers of the cranial meninges?
dura mater, arachnoid mater, and pia mater
Cerebral Spinal Fluid
- Protects, cushions, and nourishes the brain and spinal cord
- Removes waste
- produced by choroid plexus
- Recirculated back into blood at arachnoid granulations every 8 hours
- Found around brain/spinal cord and within ventricles in brain
Smell Nerve Tracing
Olfactory receptors > olfactory bulb > olfactory tract > sensory cortex of cerebrum (Rats Bite The Squirrels)
Vision Nerve Tracing
Light rays > cornea > anterior chamber > pupil > posterior chamber > lens > posterior cavity > retina > rods and cones > bipolar cell > ganglion cells > optic nerve > optic chiasma > thalamus > sensory cortex cerebrum > occipital lobe
Facial nerve tracing
Gustatory receptor cells in anterior 2/3 of tongue > facial nerve > medulla oblongata > thalamus > sensory cortex of cerebrum
Glossopharyngeal Nerve Tracing
Gustatory receptor cells in posterior 1/3 of tongue > glossopharyngeal nerve > medulla oblongata > thalamus > sensory cortex of cerebrum
Vagus Nerve
Gustatory receptor cells in pharynx > vagus nerve > medulla oblongata > thalamus > sensory cortex of cerebrum
Hearing - Cochlear Nerve Tracing
Sound > external ear > tympanic membrane > malleus, incus, stapes > moves perilymph in vestibular and tympanic ducts > vibrates vestibular and basilar membrane > vibrates spiral organ > tectorial membrane distorts receptor cells > cochlear nerve > thalamus > sensory cortex cerebrum > temporal lobe
Equilibrium - Vestibular Nerve tracing
Hair cells in utricle, saccule, and ampullae > vestibular nerve > medulla oblongata > cerebellum
Mechanoreceptor sensations
hearing, soft touch, and equilibrium
Proprioreceptor sensations
position of body in space
Chemoreceptor sensations
smell, taste, and pH of blood
Thermoreceptor sensations
warm and cold sensation
photoreceptor sensations
vision
baroreceptor sensation
stretch of hollow organ or tube
nociceptor sensation
painful sensation
Cranial Nerves
Olfactory, optic, oculomotor, trochlear, trigeminal, abducens, facial, vestibulocochlear, glossopharyngeal, vagus, accessory, hypoglossal
Acronym for cranial nerves
Old Owls On Tree Tops Are Forever Viewing Green Valleys And Hills
Acronym for cranial nerves sensory/motor
Some Say Money Matters But My Brother Says Big Brains Matter Most
s= somatic m= motor b=both
Olfactory nerve sensory/motor function
Sensory = smell Motor = none
Optic Nerve sensory/motor function
Sensory = vision Motor = none
Oculomotor Nerve Sensory/Motor Function
Sensory = none Motor = skeletal eye muscles and smooth eye muscles
Trochlear nerve sensory/motor function
Sensory = none Motor = skeletal eye muscles
Trigeminal sensory/motor function
Sensory = general sensation from face, eyes, mouth Motor = skeletal muscles of masticulation
Abducens sensory/motor function
Sensory = none Motor = skeletal eye muscles
Facial sensory/motor function
Sensory = taste - anterior tongue
Motor (somatic) = muscles of facial expression
Motor (Visceral) = salivary glands
Vestibulocochlear sensory and motor function
Sensory = hearing and equilibrium Motor = none
Glossopharyngeal Nerve Sensory/Motor Function
Sensory = taste; general sensations from middle ear and throat; BP and gas content in blood vessels Motor = swallowing muscles and salivary gland
Vagus nerve sensory and motor function
Sensory = general sensations from thoracic and abdominal viscera Motor = thoracic and abdominal viscera; larynx and swallowing muscles
Accessory nerve sensory and motor function
Sensory = none Motor = swallowing muscles, sternocleidomastoid and trapezius
Hypoglossal Sensory and Motor Function
Sensory = none Motor = tongue muscles
Flow of CSF Tracing