phys ex2 Flashcards
Insulin is a _____ hormone.
protein
Type II diabetes mellitus results from
insulin receptor insensitivity
The receptor for insulin is
tyrosine kinase linked
Glucagon
increases blood glucose
Polyuria, polydipsia and polyphagia are cardinal signs of
both type I and type II diabetes mellitus
Insulin
decreases blood glucose
Insulin is produced by the _____ cells of the pancreas.
beta
The alpha cells of the pancreas secrete a hormone that
increases blood glucose
Vitamin D
increases the intestinal absorption of calcium
Vitamin D deficiency in children results in
rickets
Parathyroid hormone (PTH)
increases calcium in the blood
Low calcium in the blood is known as
hypocalcemia
High calcium levels in the blood stimulates the secretion of
calcitonin
The action potentials of a neuron
all have the same amplitude
Action potentials in a myelinated axon
are saltatory
The rapid depolarization phase of an action potential is produced by
voltage-gated Na+ channels
Voltage (mV) measured across a membrane is known as
membrane potential
The concentration gradients of sodium and potassium ions across the cell membrane of neurons is established by
the Na+/K+ ATPase (sodium pump)
The resting membrane potential of cells is established and maintained by
K+ leak channels
Graded membrane potentials
vary with stimulus strength
Open Na+ channels
depolarize the cell membrane
Action potentials begin
in the axon hillock
The hyperpolarization phase of an action potential is produced by
open K+ channels
Which cell type has multiple processes that simultaneously form myelin sheathing around multiple axons?
oligodendrocyte
Secretes, circulates and maintains cerebrospinal fluid
ependyma
Which cell type forms myelin sheathing in the peripheral nervous system?
Schwann
Neuronal cell type with 2 processes emanating from the cell body
Bipolar
Glial cell that has perivascular feet
Astrocyte
Phagocytic cell of the nervous system
microglia
Nodes of Ranvier
are the sites of action potentials in myelinated axons
Acetycholine neurotransmission is terminated by
acetycholinesterase
Norepinephrine directly activates
g-protein linked receptors
Norepinephrine neurotransmission is terminated by
reuptake into the presynaptic terminal
Ligand gated channels for which ion create EPSPs?
sodium
The nicotinic acetycholine receptor
is both a sodium and potassium channel
The ion that triggers presynaptic exocytosis of neurotransmitter:
calcium
Ligand gated channels for which ion create IPSPs?
potassium
Which of the following are functions of the basal nuclei?
Plan, initiate and maintain voluntary motor activities
Regulate voluntary control of eye movements
Inhibit antagonistic and unnecessary movements
Which part of the cerebrum is involved in speech preparation and production?
Broca’s area
Which part of the brain continually produces new neurons and is crucial for learning and memory?
the hippocampus
Which cerebral lobe is involved in cutaneous and muscular sensations?
Parietal
Which cerebral lobe is involved in voluntary motor control of skeletal muscles; personality; and higher intellectual processes?
Frontal
Which is a descending (motor) spinal tract?
pyramidal
Stretch reflexes are initiated by activation of a
muscle spindle
Which is an ascending (sensory) spinal tract?
Lateral spinothalamic
The efferent component of a stretch reflex:
Alpha motor neuron
Spinal nerves contain the axons of both sensory and motor neurons.
True
