Ch 12
Nervous Tissue
Nervous Tissue
Which glial cells are considered the cleanup crew for cleaning up dead cells and debris?
Microglial Cells
What is the essential function of the brain stem?
Pathway for higher and lower brain centers
In the spinal cord, which of these areas would you find white matter?
Funiculi
Where is a spinal tap performed?
Between L3 - L5 in the subarachnoid space.
What are the 5 characteristics of neurons?
Exitability
Conductivity
Secretion
Extreme Longevity
Amitotic
Name at least 4 functions of the hypothalamus
Homeostasis:
-Feeding, thirst, and satiety centers
-Control body temp
-Regulate daily sleep patterns
-Regulate rage, aggresion, pain, pleasure, and arousal
-Endocrine fxn - hormone secretion
What happens if damage occurs above C3?
Respiratory arrest, due to damage to the phrenic nerve
This CN supplies the muscles of mastication and has sensory functions as well.
V - Trigeminal
Motor = mastication
Sensory = touch, pain, and temp receptors of the face
What is a Glioma? What causes them?
Tumor in the Nervous system, caused by mitotic glial cells.
Name 3 neurotransmitters from class with a function
ACH
Glutamate
GABA
Histamine
Norepinephrine
Dopamine
Serotonin
NO
What is the Limbic sytem consist of? What are some functions?
-Hippocampus - stores long-term memories
-Amygdala - emotional experiences, expression, perception
-Olfactory Bulb - emotional reponses to odor.
How do you identify the anterior and posterior sides of the spinal cord?
The anterior ramus is larger
Posterior horns are "sharper"
Ganglion present posteriorly
Which cranial nerve is responsible for hearing and equilibrium and has two branches?
VIII - Vestibulocochlear
Vestibule / Cochlea
Where is the cerebellum, and what are some functions?
Dorsal to pons/medulla, large mass of white/gray matter behind pons.
Corrects volunatry skeletal muscle contraction and posture.
Sense of balance/equilibrium
Language & problem solving
Recognize and predict patterns/sequences
Alcohol
What is Summation? What are the two types of summation, with an example?
Summation is the additive effect of GP's. As stimulus strength increases, the amplitude of each GP increases.
Spatial - multiple signals, multiple GPs
Temporal - Same signal causes GP's over time.
Name 5 characteristics of aging within the nervous system.
- Brain weight decreases
- Fewer synaptic contacts
- Info processing diminishes
- Voluntary motor movements slow down
- Slower reflexes
- Conduction velocity decreases (slowed AP's)
Compare and contrast Spastic and Flaccid Paralysis
Flaccid - damage to lower motor neurons characterized by paralysis on the same side as the injury, no reflex action, and decreased muscle tone (hence flaccid)
Spastic - Damage to Upper motor neurons characterized by paralysis on the opposite side of the injury, exaggerated reflexes, and increased muscle tone (stiffness)
Describe CN VII
VII - Facial
Motor fxn = facial expression, salivary glands, nasal & oral mucous glands & tears
Bell's Palsy
Describe Multiple Sclerosis (MS)
Autoimmune disorder in which myelin sheaths are destroyed by the patient's immune system (T-cells).
Loss of function over time
Symptoms: muscle weakness, abnormal sensations, double vision
No cure.
Compare and Contrast Graded potentials vs Action potentials
(At least 4 differences)
GP - in cell body/dendrites, ligand/mech gated channels, localized conduction, size and duration of GP vary upon stimulus, summation
AP - arises at the axon hillock, voltage gated channels, conducted down the axon, always the same size (all-or-nothing), very quick, refractory period
What are the 5 lobes of the brain, and what is a general function of each?
1. Frontal: personality, concentration, decision-making, planning; voluntary control of skeletal muscle.
2. Parietal: Interpret shapes & texture, understand speech and produce words, and express thoughts and emotions (Wernicke - words become speech)
3. Temporal: Understand speech, interpretation, and storage of auditory and olfactory sensations.
4. Occipital: Vision (eye focusing, interpret images)
5. Insula: Interprets taste, taste memories
1. Stimulus activates the receptor
2. Nerve signal is propagated through SENSORY neuron to spine
3. Nerve signal is processed by interneurons in the integration center.
4. Nerve signal is propagated by a MOTOR neuron
5. The effector responds.
Describe CN X
X - Vagus
Sensory = proprioception/stretching or organs
Motor =
-supplies muscles of the pharynx, larynx, & soft palate that are involved in swallowing & vocalization
-Controls cardiac/smooth muscle of viscera
-Secretion of digestive fluids, movement of food
Compare and Contrast a TIA and CVA
TIA (Transient Ischemic Attack) - "Mini stroke" caused by impaired blood flow to the brain.
Sx - dizziness, slurred speech, numbness, double vision, one-sided paralysis
Use aspirin or anticoagulants to treat; may require grafting
CVA - stroke caused by a blood clot/burst in the brain. 2 types: Ischemic & Hemorrhagic; Know risk factors..
Tx - t-PA