Nervous System and Senses Flashcards
The nervous system has two divisions:
The central nervous system (CNS)- consists of brain and spinal cord
The peripheral nervous system (PNS)- consists of cranial nerves and spinal nerves
The autonomic nervous system has two divisions:
Sympathetic and Parasympathetic
Dominant in stress situations, which include anger, fear or anxiety, as well as exercise:
Sympathetic divison
Dominates in relaxed (non-stressful) situations to promote normal functioning of several organ systems:
Parasympathetic division
Nerve cells are called:
Neurons or nerve fibers
What is essential for the continued life of the neuron:
The cell body with contains the nucleus
Extensions that transmit impulses towards the cell body:
Dendrites
Transmits impulses away from the cell body:
Axon
It is the cell membrane of the dendrites, axon and cell body that carries the:
Electrical nerve impulse
Axons and dendrites are wrapped in specialized cells called:
Schwann cells
The most important of the neuroglia in the peripheral nervous system:
Schwann cells
Phospholipid that electrically insulates neurons from one another:
Myelin
The spaces between adjacent a Schwann cells, or segments of the myelin sheath, are called:
Nodes of Ranvier (neurofibral nodes)
The nuclei and cytoplasm of the Schwann cells are outside the myelin sheath and are called:
The neurolemma
Produce a chemical growth that stimulates regeneration:
Schwann cells
Regulate the environment around the neurons, provide a supporting framework for neural tissue and acts as phagocytes:
Neuroglia
The small space between the axon of one neuron and the dendrites or cell body of the next neuron is the:
Synapse
One important consequence of the presence of synapses is that they ensure:
One-way transmission of impulses in a living person
Electrical change created by the movement of certain ions through the cell membrane:
Nerve impulse
Nerve impulse transmission changes from electrical to chemical and depends on the release of neurotransmitters:
At synapses
Neurons may be classified into three groups:
- Sensory neurons
- Motor neurons
- Interneurons
Carry impulses from the receptors to the central nervous system:
Sensory neurons
Carry impulses from the central nervous system to the effectors:
Motor neurons
Sensory and motor neurons make up the:
Peripheral nervous system
Interneurons are found entirely within:
The central nervous system
A group of axons and/or dendrites of many neurons with blood vessels and connective tissue:
Nerve
Groups of neurons within in the central nervous system:
Nerve tract
Movement of the eyeball, constriction of the pupil in bright light or for near vision:
Oculomotor
Sensory in cardiac, sensory for cardiac, respiratory, and blood pressure reflexes, decreases heart rate, contraction of alimentary tube (peristalsis), increases digestive secretions:
Vagus
Involuntary response to a stimulus, that is, an automatic action stimulated by a specific change of some kind:
Reflex
Help keep us upright without our having to think about doing so:
Stretch reflexes
Stimulus is something painful and potentially harmful, and the response is to pull away from it:
Flexor reflexes (withdrawal reflexes)
Pathway nerve impulses travel when a reflex is elicited:
Reflex arc
Four cavities within the brain, each contain a capillary network which forms cerebrospinal fluid:
Ventricles
Cardiac centers that regulate heart rate, vasomotor centers that regulate the diameter of blodd vessels and respiratory centers that regulate breathing:
Medulla
Two respiratory centers that work with the medulla to produce a normal respiratory rhythm:
Pons
Visual and auditory reflexes:
Midbrain
All functions are concerned with movement:
Cerebellum
Largest part of the brain:
Cerebrum
Surface of the cerebrum is called the:
Cerebral cortex
Motor areas that generate the impulses for voluntary movement:
Frontal Lobe
Reveice impulses from receptors in the skin and feel and interpret the cutaneous sensations:
Parietal Lobe
Auditory area and olfactory area for hearing and smelling:
Temporal Lobe
Impulses from the retinas of the eyes travel along the optic nerves to the visual areas of the:
Occipital Lobes
Connective tissue membranes that cover the brain and spinal cord are called:
Meninges
Three layers of the meninges:
- Dura mater
- Arachnoid membrane
- Pia mater
Constantly provide us with information about our surroundings: we see, hear and touch:
Our senses
Sensation seems to come from the area where the receptors were stimulated:
Projection
Sensations felt more distinctly and to a greater degree than are others:
Intensity
Effect of a previous or simultaneous sensation on a current sensation:
Contrast
Becoming unaware of a continuing stimulus:
Adaptation
Sensation remains in the sonsciousness even after the stimulus has stopped:
After-image
Provide us with information about the external environment and also about the skin itself:
Cutaneous senses
Pain that originates inan internal organ may be felt in a cutaneous area:
Referred pain
Detect stretching of muscles and generate impulses, which enable the brain to create a mental picture to know where the muscles are and how they are positioned:
Stretch receptors (prorioceptors or muscle spindles)
Conatin skeletal muscle that enables them to close and cover the front of the eyeball:
Keep dust out of the eyes, on the border of each eyelid:
Eyelashes
Eyelids lined with a thin membrane called the:
Conjunctiva
Located at the upper, outer corner of the eyeball, within the orbit:
Lacrimal glands
The eyeball is within and protected by the:
Orbit
Thickest layer of the eyeball and is made of fibrous connective tissue which is visible as the white of the eye:
Sclera
Differs from the rest of the sclera in that it is transparent and has no capillaries:
Cornea
Contains blood vessels and a dark blue pigment that absorbs light within the eyeball and thereby prevents glare:
Choroid layer
Transparent, elastic protein and has no capillaries:
Lens
Colored part of the eye:
Iris
Lines the posterior two thirds of the eyeball and contains the visual receptors, the rods and cones:
Retina
Detect the presence of light:
Detect colors:
Rods
Cones
A small depression directly behind the center of the lens and is the area for best color vision:
Fovea
These neurons, carrying the impulses generated by the rods and cones all converge at the:
Pass through the wall of the eyeball as the:
Optic disc
Optic nerve
The larger posterior cavity is found between the lens and retina and contains:
Vitreous humor
The anterior cavity found between the front of the lens and the cornea and contains:
Aqueous humor
Ear contains two receptors for two senses:
Hearing and equilibrium
The outer ear consists of:
Auricle and ear canal
An air-filled cavity in the temporal bone:
Middle ear
Stretched across the end of the ear canal and vibrates when sound waves strike it:
Ear drum or Tympanic membrane
Extends from the middle ear to the nasopharynx and permits air to enter or leave the middle ear cavity:
Eustachian tube
Cavity containing the structures concerned with hearing and equilibrium:
Inner ear
Membranous sacs in the inner ear:
Utricle and saccule
