Physiology Topics and Vocabulary from Chapters 7, 8, 10, 11 of Essentials of Hum
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- 2 Components of Structural Classification for the Nervous System
- Central nervous system + Peripheral nervous system
- Central nervous system (CNS) consists of: (2)
- brain + spinal cord
- What does the CNS do?
- Interpret incomy sensory information and issue instructions based on past experience and current conditions.
- Peripheral nervous system (PNS) consists of: (2)
- Spinal nerves + cranial nerves
- 2 Components of Functional Classification of the Nervous System
- sensory/afferent division + motor/efferent division
- consists of nerve fibers that convey impulses to the CNS from the sensory receptors located in various parts of the body
- sensory/afferent division
- Carries impulses from CNS to effector organs, muscles, and glands
- motor/efferent division
- 2 subdivisions of the motor division
- somatic + autonomic
- somatic nervous system
- voluntary movement/control + skeletal muscle reflexes
- autonomic nervous system
- regulates events that are automatic/involuntary ie; activity of smooth and cardiac muscles and glands
- 2 subdivisions of the autonomic nervous system
- sympathetic and parasympathetic
- Supporting cells in the CNS that are like "nerve glue."
- neuroglia
- 5 types of glial cells in the CNS
-
Astrocyte
microglial cell
ependymal cells
oligodendrocyte
sensory neuron w/ Schwann cells and satellite cells - abundant star-shaped cells that account for nearly half of the neural tissue w/ swollen ends that cling to neurons. _____ form a living barrier between capillaries and neurons and play a role in making exchanges between the two; protect neurons from harm
- astrocytes
- spiderlike phagocytes that dispose of debris, including dead brain cells and bacteria
- microglia
- line the cavaties of the brain and the spinal cord. the beating of their cilia helps to circulate the cerebrospinal fluid that fills those cavaties and forms a protective cushion around the CNS.
- ependymal cells
- glia that wrap their flat extensions tightly around the nerve fibers, producing fatty insulating coverings called myelin sheaths; not able to transmit impulses
- oligodendrocytes
- 2 types of glial cells in the PNS
-
Schwann cells
satellite cells - glial cells that form the myelin sheaths around nerve fibers in the PNS
- Schwann cells
- glial cells that act as protective, cushioning cells.
- satellite cells
- nueron processes that convey incoming messages toward the cell body
- dendrites
- Neuron processes that convey incoming messages away from the cell body
- axons
- conelike region of the cell body
- axon hillock
- Part of the Schwann cell that is external to the myelin sheath
- neurilemma
- gaps between Schwann cells
- nodes of Ranvier
- unlike Schwann cells, oliogodendrocytes don't have ____.
- neurilemma
- 1 difference between oliogodendrocytes and Schwann cells
- oliogodendrocytes can cover up to 60 different fibers at the same time
- neurons carrying impulses from sensory receptors
- sensory/afferent neurons
- sensory receptors in the skin are called ____ whereas sensory receptors in muscles and tendons are called ____.
- cutaneous sense organs, proprioceptors
- The pain receptors (actually ____ dendrite endings) are the ____ specialized of the cutaneous receptors.
- bare; least
- Strong stimulation of any of the cutaneous receptros is also interpreted as ____.
- pain
- The proprioceptors detect the amount of ____ or ____ in skeletal muscles, their tendons, and their joints.
- stretch; tension
- Neurons carrying impulses from the CNS to the viscera and/or muscles and glands.
- motor/efferent neurons
- The cell bodies of sensory neurons are always found in a ____ outside the CNS.
- ganglion
- The cell bodies of motor neurons are always located in the ____.
- CNS
- ____ connect the motor and sensory neurons in neural pathways. Their cell bodies are always located in the CNS.
- association neurons or interneurons
- If there are several processes extending from the cell body, the neuron is a ____.
- multipolar neuron
- ____ is the most common neuron structural type.
- multipolar neruon
- Neurons with two processes - an axon and a dendrite - are called ____.
- bipolar neurons
- ____ are rare in adults and are found in only some special sense organs like the eyes and nose.
- bipolar neurons
- ____ have a single process emerging from the cell body. However, it is very short and divides almost immediately into proximal and distal processes.
- Unipolar neurons
- Sensory neurons found in PNS ganglia are ____.
- unipolar
- The plasma of a resting, or inactive, neuron is ____.
- polarized
- The major positive ions inside the neuron cell are ____.
- potassium (K+)
- The major positive ions outside the neuron cell are ___.
- sodium (Na+)
- This inward rush of sodium ions changes the polarity of the neuron's membrane at a site.
- depolarization
- The ____ or nerve impulse is an ____ response.
- action potential; all-or-none
- This outflow of positive ions from the cell restores the electrical conditions at the membrane to the poloarized, or resting, state.
- repolarization
- Until ____ occurs, a neuron cannot conduct another impulse.
- repolarization
- The sodium-potassium pump uses ____ to pump excess sodium ions out of the cell and to bring potassium ions back into it.
- ATP
- Fibers that have ____ conduct impulses much faster.
- myelin sheaths
- sedatives and anesthetics block nerve impulses by altering ____.
- membrane permeability
- ____ are rapid, predictable, and involuntary responses to stimuli.
- Reflexes
- ____ reflexes include all reflexes that stimulate the skeletal muscles.
- somatic
- ____ reflexes regulate the activity of smooth muscles, the heart, and glands.
- autonomic
- ____ reflexes regulate such body functions as digestion, elimination, blood pressure, and sweating
- autonomic
- The entire surface of the cerebral hemispheres exhibits elevated ridges of tissue called ____, separated by shallow grooves called ____. Less numerous are the deeper grooves called ____.
- gyri; sulci; fissures
- 4 cranial lobes
- frontal, parietal, occipital, temporal
- The somatic sensory area is located in the ____ lobe posterior to the central sulcus.
- parietal
- The ____ that allows us to consciously move our skeletal muscles is anterior to the central sulcus in the ____ lobe.
- primary motor area; frontal
- ____ is a specialezed area that is very involved in our ability to speak.
- Broca's area
- Areas involved in ____ and ____ are believed to be in the ____ part of the ____ lobes.
- higher intellectual reasoning; socially acceptable behavior; anterior; frontal
- Complex memories appear to be stored in the ____ and ____ lobes.
- temporal; frontal
- The ____ is located at the junction of the temporal, parietal, and occipital lobes.
- speech area
- The cell bodies of neurons involved in the cerebral hemisphere functions are found only in the outermost ____ of the cerebrum, the ____.
- gray matter; cerebral cortex
- Most of the remaining cerebral hemisphere tissue - the deeper cerebral ____ - is composed of fiber tracts carrying impulses to or from the cortex.
- white matter
- One very large fiber tract, the ____, connects the cerebral hemispheres.
- corpus callosum
- Isolated spots of gray matter, called ____, help regulate voluntary motor activities by modifying instructions sent to the skeletal muscles by the primary motor cortex.
- basal ganglia
- The ____ sits atop the brain stem and is enclosed by the cerebral hemispheres.
- diencephalon
- Major structures of the diencephalon (3)
- thalamus, hypothalamus, epithalamus
- The ____, which encloses the shallow third ventricle of the brain, is a relay station for sensory impulses passing upward to the sensory cortex.
- thalamus
- As impulses surge through the ____, we have a crude recognition of whether the sensation we are about to have is pleasant or unpleasant.
- thalamus
- The ____ makes up the floor of the diencephalon and is an important autonomic nervous system center b/c it plays a role in the regulation of body temperature, water balance, and metabolism. It is also the center for many drives and emotions and an import
- hypothalamus
- Thirst, appetite, sex, pain, and pleasure centers are in the ____.
- hypothalamus
- The ____ hangs from the anterior floor of the hypothalamus by a slender stalk.
- pituitary gland
- The ____, reflex centers involved in olfaction, bulge from the floor of the hypothalamus posterior to the pituitary gland.
- mammillary bodies
- The ____ forms the roof of the third ventricle. Important parts are the pineal body and the choroid plexus of the third ventricle.
- epithalamus
- The ____ consists of the midbrain, pons, and medulla oblongata
- brain stem
- The ____ extends from the mammillary bodies to the pons inferiorly.
- midbrain
- The ____ is a tiny canal that travels through the midbrain and connects the third ventricle of the diencephalon to the fourth ventricle below.
- cerebral aquaduct
- The ____ is the rounded structure that protrudes just below the midbrain and it has important nuclei involved in the control of breathing.
- pons
- The ____ is the most inferior part of the brain stem and it merges into the spinal cord below without any obvious change in structure. It is an important fiber tract area. It contains many nuclei that regulate vital visceral activities. It contains vente
- medulla oblongata
- Extending the entire length of the brain stem is a diffuse mass of gray matter, the ____, the neurons of which are involved in motor control of the visceral organs.
- reticular formation
- The large, cauliflowerlike ____ projects dorsally from under the occipital lobe of the cerebrum. It has two hemispheres and a convoluted surface.
- cerebellum
- The ____ provides the precise timing for skeletal muscle activity and controls our balance and equilibrium. This makes movements smooth and coordinated.
- cerebellum
- Three connective tissue membranes covering and protecting the CNS structures are ____.
- meninges
- The outermost layer of the meninges is called ____ and is a double-layered membrane where it surroundes the brain.
- dura mater
-
____
/
dura mater
\
____ -
periosteum
meningeal layer - The middle meningeal layer is the weblike ____.
- arachnoid mater
- The innermost membrane is called the ____ which clings to the surface of the brain.
- pia mater
- ____ is a watery "broth" similar in its makeup to blood plasma, from which it forms. However, it contains less protein, more vitamin C, and its ion composition is different.
- Cerebrospinal fluid
- The ____ is composed of the least permeable capillaries in the body in order to protect the brain's nerves from substances in the blood.
- blood-brain barrier
- A ____ is a bundle of neuron fibers found outside the CNS.
- nerve
- Fiber bundles, or ____ are bound together by a tough fibrous sheath, the ____, to form the cordlike nerve.
- fascicles, epineurium
- Name the 12 pairs of cranial nerves.
-
I. Olfactory
II. Optic
III. Oculomotor
IV. Trochlear
V. Trigeminal
VI. Abducens
VII. Facial
VIII. Vestibulocochlear
IX. Glossopharyngeal
X. Vagus
XI. Accessory
XII. Hypoglossal - CN: carries impulses for the sense of smell
- olfactory
- CN: carries impulses for vision
- optic
- CN: supplies motor fibers to four of the six muscles that direct the eyeball; to the eyelid; and to the internal eye muscles controlling lens shape and pupil size
- oculomotor
- CN: supplies motor fibers for one external eye muscle
- trochlear
- CN: conducts sensory impulses from the skin of the face and mucosa of the nose and mouth; also contains motor fibers that activate teh chewing muscles
- trigeminal
- CN: supplies motor fibers to the lateral rectus muscle, which rolls the eye laterally
- abducens
- CN: activates the muscles of facial expression and the lacrimal and salivary glands; carries sensory impulses from the taste buds of anterior tongue
- facial
- CN: transmits impuses for the sense of balance, and transmits impulses for the sense of hearing
- vestibulocochlear
- CN: supplies motor fibers to the pharynx that promote swallowing and saliva production; carries sensory impulses from taste buds of the posterior tongue and from pressure receptors of the carotid artery
- glossopharyngeal
- CN: fibers carry sensory impulses from and motor impulses to the pharynx, larynx, and the abdominal and thoracic viscera; most motor fibers are parasympathetic fibers that promote digestive activity and help regulate heart activity
- vagus
- CN: mostly motor fibers that activate the sternocleidomastoid and trapezius muscles
- accessory
- CN: motor fibers control tongue movements; sensory fibers carry impulses from the tongue
- hypoglossal
- ____ produce an oily secretion that lubricates the eye.
- Tarsal glands
- A delicate membrane, the ____, lines the eyelids and covers part of the outer surface of the eyeball. It also secretes mucus which helps to lubricate the eyeball and keep it moist.
- conjunctiva
- The ____ are located above the lateral end of each eye. They continually release a dilute salt solution (tears) onto the anterior surface of the eyeball through several small ducts.
- lacrimal glands
- The eyeball has a wall composed of three ____, or coats, and its interior is filled with fluids called ____ that help maintain its shape.
- tunics, humors
- The outermost tunic, the protective ____ is thick, white connective tissue.
- sclera
- The transparent "window" of the eye is the ____ through which light enters the eye.
- cornea
- The ____ is the only tissue of the body that can be transplanted from one person to another without the worry of rejection.
- cornea
- The ____ tunic is composed of the choroid, ciliary body, and iris
- vascular
- The ____ is a blood-rich tunic that contains a dark pigment in order to keep light from scattering inside the eye.
- choroid
- The choroid is modified to form two smooth muscle structures, the ____, to which the ____ is attached by a suspensory ligament called the ____.
- ciliary body; lens; ciliary zonule
- The pigmented ____ has a rounded opening, the ____, through which light passes.
- iris; pupil
- The innermost sensory tunic of the eye is the delicate white ____, which extends anteriorly only to the ciliary body.
- retina
- The retina contains millions of receptor cells, the ____ and ____ which are called photoreceptors because they respond to light.
- rods; cones
- Lateral to each blind spot is the ____, a tiny pit that contains only cones.
- fovea centralis
- Cones respond to ____, ____, and ____ light.
- red, green, blue
- When all three cone types are being stimulated, we see ____.
- white
- The lens divides the eye into two chambers: the anterior segment, anterior to the lens, contains a clear watery fluid called ____ and the posterior segment, posterior to the lens, is filled with a gel-like substance called ____.
- aqueous humor; vitreous humor
- ____ helps precent the eyeball from collapsing inward.
- vitreous humor
- ____ is similar to blood plasma and is continually secreted by a special area of the choroid.
- aqueous humor
- Aqueous humor is reabsorbed into the venous blood through the ____, which is located at the junction of the sclera and cornea.
- scleral venous sinus
- The ____ the lens convexity, the more it bends the light whereas the ____ the lens, the less it bends light.
- greater; flatter
- The ability of the eye to focus specifically for close objects is called ____.
- accommodation
- At the ____ the fibers from the medial side of each eye cross over to the opposite side.
- optic chiasma
- The external muscles of the eye are responsible for ____, which is a reflexive movement of the eyes medially when we view close objects.
- convergence
- When the eyes are suddenly exposed to bright light, the pupils immediately constrict; this is the ____.
- photopupillary reflex
- The pupils constrict refelxively when we view close objects; this ____ provides for more acute vision.
- accommodation pupillary reflex
- The outer ear is composed ot the pinna, or ____, is what most people call the "ear" - the shell-shaped structure surrounding the auditory canal opening.
- auricle
- The ____ is a short, narrow chamber carved into the temporal bone of the skull.
- external acoustic meatus
- Sound waves entering the external auditory canal eventually hit the ____, or eardrum, and cause it to vibrate.
- tympanic membrane
- The middle ear, or ____, is a small, air-filled cavity within the temporal bone.
- tympanic cavity
- The auditory tube runs obliquely downward to link the middle ear cavity with the ____.
- throat
- The tympanic cavity is spanned by the three smallest bones in the body, the ____, which transmit the vibratory motion of the eardrum to the fluids of the inner ear.
- ossicles
- The three ossicles:
-
hammer (malleus)
anvil (incus)
stirrup (stapes) - The inner ear is a maze of bony chambers called the ____, or bony, labyrinth, located deep within the temporal bone, and just behind the eye socket.
- osseous
- The 3 subdivisions of the bony labyrinth
- cochlea, vestibule, semicircular canals
- The bony labyrinth is filled with a plasmalike fluid called ____.
- perilymph
- Suspended in the perilymph is a ____, a system of membrane sacs that more or less follows the shape of the bony labyrinth.
- membranous labyrinth
- The membranous labyrinth contains a thick fluid called ____.
- endolymph