10+ Flashcards
The cytoplasmic extensions that, together with the cell body, provide the main receptive surfaces for neurons are
Dendrites
Masses of myelinated nerve fibers appear
White
Which of the following is a type of neuroglial cell?
Astrocyte
Oligodendrocyte
Ependymal cell
All of these are correct
What are three types of neuroglial cells?
Asrocytes, oligodendrocytes, and Ependymal cells
List the parts of a reflex arc.
Receptor, sensory neurons, inter neuron, motor neuron, effector
When a nerve fiber is polarized, the concentration of sodium ions is ____ while potassium ion are ______
Higher on outside of membrane
Potassium ions are higher on inside
Saltatory conduction is
Faster than conduction on an unmyelinated fiber
What produces myelin in the brain and spinal cord?
Oligodendrocytes
Thick and myelinated cells allow things to
Travel faster
What passes through cell membranes most readily? (Neuroglial cells)
Potassium
Most of the neurons in the brain and spinal cord are
Multipolar
Reflexes help control what three things
Heart rate
Blood pressure
And digestive activities
Three general functions of the nervous system are
Integrative, motor, and sensory neurons
Neurons are
Whereas neuroglial cells are
Nerve cells
Structural and functional units of the nervous system
What is myelin?
A lipoprotein on the outside of the axon
The somatic nervous system controls
Skeletal muscle contraction
What is under voluntary control of the nervous system?
The skeletal muscle system
When a stimulus is great enough to change the membrane potential and propagate an action it is called
Threshold potential
Nodes of ranvier occur between
Myelin sheaths
What is a reflex?
An automatic unconscious response to changes occurring inside or outside of the body
Outside of the brain and spinal cord, myelin sheaths of —– cells often enclose larger axons
Schwann
What occurs when you enter a room and smell a strong odor which fades?
Sensory adaptation
Olfactory receptors are
Chemoreceptors
5 primary taste sensations
Sweet, salty, sour, bitter, and umami
Loss of smell is called
Anosmia
Acupuncture relieves pain by releasing
Enkephalins
Treatment for cataracts usually involves the removal of the
Lens
Most common cause of deafness
Torn tympanic membrane
Glaucoma is caused by a
Build-up of aqueous humor
Special senses are found
In the head
Light touch receptors are
Tactile corpuscles
Deep pressure receptors
Lamellated corpuscles
Lacrimal glands
Produce tears
Thin and myelinated pain fibers
Vs thick and unmyelinated
Acute
Chronic
Rods are more/ less sensitive to light than cones
More
Cones for color
Rhodopsin is broken down by light into
Ops in
Pain receptors are generally stimulated by
Factors that can cause nerve damage
Taste receptors are
Modified epithelial cells
Lens of eye thickens when the
Ciliary muscles contract
Rhodopsin is found in
Rod cells
Temperature sensation depends on two types of
Free nerve endings
Dermal papillae are
Modified epithelial cells
The Eustachian tube connects the
Middle ear to the throat
Percentage of solids in blood
45%
55% plasma
Biconcave cells in blood that lack nuclei when mature
Red blood cells
Normal white blood cell count is
5,000-10,000 cells/ mm3 of blood
Platelets are
Cytoplasmic fragments of cells
Platelets release vasoconstricting substances called ____ when forming a plug
Serotonin
Sickle-cell anemia is caused by an
Abnormal form of hemoglobin
Pulmonary embolism comes from a clot reaching a lung through
A pulmonary artery
Thrombocytopenia is due to
A deficiency of platelets
Final formation in blood clot formation is
Thrombin converts fibrinogen to fibrin
What lack nuclei, release serotonin, and number from 130,000-360,000/mm3 blood?
Platelets
