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  1. Preface
  2. Unit 1: Levels of Organization
    1. 1 An Introduction to the Human Body
      1. Introduction
      2. 1.1 Overview of Anatomy and Physiology
      3. 1.2 Structural Organization of the Human Body
      4. 1.3 Functions of Human Life
      5. 1.4 Requirements for Human Life
      6. 1.5 Homeostasis
      7. 1.6 Anatomical Terminology
      8. 1.7 Medical Imaging
      9. Key Terms
      10. Chapter Review
      11. Interactive Link Questions
      12. Review Questions
      13. Critical Thinking Questions
    2. 2 The Chemical Level of Organization
      1. Introduction
      2. 2.1 Elements and Atoms: The Building Blocks of Matter
      3. 2.2 Chemical Bonds
      4. 2.3 Chemical Reactions
      5. 2.4 Inorganic Compounds Essential to Human Functioning
      6. 2.5 Organic Compounds Essential to Human Functioning
      7. Key Terms
      8. Chapter Review
      9. Interactive Link Questions
      10. Review Questions
      11. Critical Thinking Questions
    3. 3 The Cellular Level of Organization
      1. Introduction
      2. 3.1 The Cell Membrane
      3. 3.2 The Cytoplasm and Cellular Organelles
      4. 3.3 The Nucleus and DNA Replication
      5. 3.4 Protein Synthesis
      6. 3.5 Cell Growth and Division
      7. 3.6 Cellular Differentiation
      8. Key Terms
      9. Chapter Review
      10. Interactive Link Questions
      11. Review Questions
      12. Critical Thinking Questions
    4. 4 The Tissue Level of Organization
      1. Introduction
      2. 4.1 Types of Tissues
      3. 4.2 Epithelial Tissue
      4. 4.3 Connective Tissue Supports and Protects
      5. 4.4 Muscle Tissue and Motion
      6. 4.5 Nervous Tissue Mediates Perception and Response
      7. 4.6 Tissue Injury and Aging
      8. Key Terms
      9. Chapter Review
      10. Interactive Link Questions
      11. Review Questions
      12. Critical Thinking Questions
  3. Unit 2: Support and Movement
    1. 5 The Integumentary System
      1. Introduction
      2. 5.1 Layers of the Skin
      3. 5.2 Accessory Structures of the Skin
      4. 5.3 Functions of the Integumentary System
      5. 5.4 Diseases, Disorders, and Injuries of the Integumentary System
      6. Key Terms
      7. Chapter Review
      8. Interactive Link Questions
      9. Review Questions
      10. Critical Thinking Questions
    2. 6 Bone Tissue and the Skeletal System
      1. Introduction
      2. 6.1 The Functions of the Skeletal System
      3. 6.2 Bone Classification
      4. 6.3 Bone Structure
      5. 6.4 Bone Formation and Development
      6. 6.5 Fractures: Bone Repair
      7. 6.6 Exercise, Nutrition, Hormones, and Bone Tissue
      8. 6.7 Calcium Homeostasis: Interactions of the Skeletal System and Other Organ Systems
      9. Key Terms
      10. Chapter Review
      11. Review Questions
      12. Critical Thinking Questions
    3. 7 Axial Skeleton
      1. Introduction
      2. 7.1 Divisions of the Skeletal System
      3. 7.2 The Skull
      4. 7.3 The Vertebral Column
      5. 7.4 The Thoracic Cage
      6. 7.5 Embryonic Development of the Axial Skeleton
      7. Key Terms
      8. Chapter Review
      9. Interactive Link Questions
      10. Review Questions
      11. Critical Thinking Questions
    4. 8 The Appendicular Skeleton
      1. Introduction
      2. 8.1 The Pectoral Girdle
      3. 8.2 Bones of the Upper Limb
      4. 8.3 The Pelvic Girdle and Pelvis
      5. 8.4 Bones of the Lower Limb
      6. 8.5 Development of the Appendicular Skeleton
      7. Key Terms
      8. Chapter Review
      9. Interactive Link Questions
      10. Review Questions
      11. Critical Thinking Questions
    5. 9 Joints
      1. Introduction
      2. 9.1 Classification of Joints
      3. 9.2 Fibrous Joints
      4. 9.3 Cartilaginous Joints
      5. 9.4 Synovial Joints
      6. 9.5 Types of Body Movements
      7. 9.6 Anatomy of Selected Synovial Joints
      8. 9.7 Development of Joints
      9. Key Terms
      10. Chapter Review
      11. Interactive Link Questions
      12. Review Questions
      13. Critical Thinking Questions
    6. 10 Muscle Tissue
      1. Introduction
      2. 10.1 Overview of Muscle Tissues
      3. 10.2 Skeletal Muscle
      4. 10.3 Muscle Fiber Contraction and Relaxation
      5. 10.4 Nervous System Control of Muscle Tension
      6. 10.5 Types of Muscle Fibers
      7. 10.6 Exercise and Muscle Performance
      8. 10.7 Cardiac Muscle Tissue
      9. 10.8 Smooth Muscle
      10. 10.9 Development and Regeneration of Muscle Tissue
      11. Key Terms
      12. Chapter Review
      13. Interactive Link Questions
      14. Review Questions
      15. Critical Thinking Questions
    7. 11 The Muscular System
      1. Introduction
      2. 11.1 Interactions of Skeletal Muscles, Their Fascicle Arrangement, and Their Lever Systems
      3. 11.2 Naming Skeletal Muscles
      4. 11.3 Axial Muscles of the Head, Neck, and Back
      5. 11.4 Axial Muscles of the Abdominal Wall, and Thorax
      6. 11.5 Muscles of the Pectoral Girdle and Upper Limbs
      7. 11.6 Appendicular Muscles of the Pelvic Girdle and Lower Limbs
      8. Key Terms
      9. Chapter Review
      10. Review Questions
      11. Critical Thinking Questions
  4. Unit 3: Regulation, Integration, and Control
    1. 12 The Nervous System and Nervous Tissue
      1. Introduction
      2. 12.1 Basic Structure and Function of the Nervous System
      3. 12.2 Nervous Tissue
      4. 12.3 The Function of Nervous Tissue
      5. 12.4 The Action Potential
      6. 12.5 Communication Between Neurons
      7. Key Terms
      8. Chapter Review
      9. Interactive Link Questions
      10. Review Questions
      11. Critical Thinking Questions
    2. 13 Anatomy of the Nervous System
      1. Introduction
      2. 13.1 The Embryologic Perspective
      3. 13.2 The Central Nervous System
      4. 13.3 Circulation and the Central Nervous System
      5. 13.4 The Peripheral Nervous System
      6. Key Terms
      7. Chapter Review
      8. Interactive Link Questions
      9. Review Questions
      10. Critical Thinking Questions
    3. 14 The Somatic Nervous System
      1. Introduction
      2. 14.1 Sensory Perception
      3. 14.2 Central Processing
      4. 14.3 Motor Responses
      5. Key Terms
      6. Chapter Review
      7. Interactive Link Questions
      8. Review Questions
      9. Critical Thinking Questions
    4. 15 The Autonomic Nervous System
      1. Introduction
      2. 15.1 Divisions of the Autonomic Nervous System
      3. 15.2 Autonomic Reflexes and Homeostasis
      4. 15.3 Central Control
      5. 15.4 Drugs that Affect the Autonomic System
      6. Key Terms
      7. Chapter Review
      8. Interactive Link Questions
      9. Review Questions
      10. Critical Thinking Questions
    5. 16 The Neurological Exam
      1. Introduction
      2. 16.1 Overview of the Neurological Exam
      3. 16.2 The Mental Status Exam
      4. 16.3 The Cranial Nerve Exam
      5. 16.4 The Sensory and Motor Exams
      6. 16.5 The Coordination and Gait Exams
      7. Key Terms
      8. Chapter Review
      9. Interactive Link Questions
      10. Review Questions
      11. Critical Thinking Questions
    6. 17 The Endocrine System
      1. Introduction
      2. 17.1 An Overview of the Endocrine System
      3. 17.2 Hormones
      4. 17.3 The Pituitary Gland and Hypothalamus
      5. 17.4 The Thyroid Gland
      6. 17.5 The Parathyroid Glands
      7. 17.6 The Adrenal Glands
      8. 17.7 The Pineal Gland
      9. 17.8 Gonadal and Placental Hormones
      10. 17.9 The Endocrine Pancreas
      11. 17.10 Organs with Secondary Endocrine Functions
      12. 17.11 Development and Aging of the Endocrine System
      13. Key Terms
      14. Chapter Review
      15. Interactive Link Questions
      16. Review Questions
      17. Critical Thinking Questions
  5. Unit 4: Fluids and Transport
    1. 18 The Cardiovascular System: Blood
      1. Introduction
      2. 18.1 An Overview of Blood
      3. 18.2 Production of the Formed Elements
      4. 18.3 Erythrocytes
      5. 18.4 Leukocytes and Platelets
      6. 18.5 Hemostasis
      7. 18.6 Blood Typing
      8. Key Terms
      9. Chapter Review
      10. Interactive Link Questions
      11. Review Questions
      12. Critical Thinking Questions
    2. 19 The Cardiovascular System: The Heart
      1. Introduction
      2. 19.1 Heart Anatomy
      3. 19.2 Cardiac Muscle and Electrical Activity
      4. 19.3 Cardiac Cycle
      5. 19.4 Cardiac Physiology
      6. 19.5 Development of the Heart
      7. Key Terms
      8. Chapter Review
      9. Interactive Link Questions
      10. Review Questions
      11. Critical Thinking Questions
    3. 20 The Cardiovascular System: Blood Vessels and Circulation
      1. Introduction
      2. 20.1 Structure and Function of Blood Vessels
      3. 20.2 Blood Flow, Blood Pressure, and Resistance
      4. 20.3 Capillary Exchange
      5. 20.4 Homeostatic Regulation of the Vascular System
      6. 20.5 Circulatory Pathways
      7. 20.6 Development of Blood Vessels and Fetal Circulation
      8. Key Terms
      9. Chapter Review
      10. Interactive Link Questions
      11. Review Questions
      12. Critical Thinking Questions
    4. 21 The Lymphatic and Immune System
      1. Introduction
      2. 21.1 Anatomy of the Lymphatic and Immune Systems
      3. 21.2 Barrier Defenses and the Innate Immune Response
      4. 21.3 The Adaptive Immune Response: T lymphocytes and Their Functional Types
      5. 21.4 The Adaptive Immune Response: B-lymphocytes and Antibodies
      6. 21.5 The Immune Response against Pathogens
      7. 21.6 Diseases Associated with Depressed or Overactive Immune Responses
      8. 21.7 Transplantation and Cancer Immunology
      9. Key Terms
      10. Chapter Review
      11. Interactive Link Questions
      12. Review Questions
      13. Critical Thinking Questions
  6. Unit 5: Energy, Maintenance, and Environmental Exchange
    1. 22 The Respiratory System
      1. Introduction
      2. 22.1 Organs and Structures of the Respiratory System
      3. 22.2 The Lungs
      4. 22.3 The Process of Breathing
      5. 22.4 Gas Exchange
      6. 22.5 Transport of Gases
      7. 22.6 Modifications in Respiratory Functions
      8. 22.7 Embryonic Development of the Respiratory System
      9. Key Terms
      10. Chapter Review
      11. Interactive Link Questions
      12. Review Questions
      13. Critical Thinking Questions
    2. 23 The Digestive System
      1. Introduction
      2. 23.1 Overview of the Digestive System
      3. 23.2 Digestive System Processes and Regulation
      4. 23.3 The Mouth, Pharynx, and Esophagus
      5. 23.4 The Stomach
      6. 23.5 The Small and Large Intestines
      7. 23.6 Accessory Organs in Digestion: The Liver, Pancreas, and Gallbladder
      8. 23.7 Chemical Digestion and Absorption: A Closer Look
      9. Key Terms
      10. Chapter Review
      11. Interactive Link Questions
      12. Review Questions
      13. Critical Thinking Questions
    3. 24 Metabolism and Nutrition
      1. Introduction
      2. 24.1 Overview of Metabolic Reactions
      3. 24.2 Carbohydrate Metabolism
      4. 24.3 Lipid Metabolism
      5. 24.4 Protein Metabolism
      6. 24.5 Metabolic States of the Body
      7. 24.6 Energy and Heat Balance
      8. 24.7 Nutrition and Diet
      9. Key Terms
      10. Chapter Review
      11. Review Questions
      12. Critical Thinking Questions
    4. 25 The Urinary System
      1. Introduction
      2. 25.1 Physical Characteristics of Urine
      3. 25.2 Gross Anatomy of Urine Transport
      4. 25.3 Gross Anatomy of the Kidney
      5. 25.4 Microscopic Anatomy of the Kidney
      6. 25.5 Physiology of Urine Formation
      7. 25.6 Tubular Reabsorption
      8. 25.7 Regulation of Renal Blood Flow
      9. 25.8 Endocrine Regulation of Kidney Function
      10. 25.9 Regulation of Fluid Volume and Composition
      11. 25.10 The Urinary System and Homeostasis
      12. Key Terms
      13. Chapter Review
      14. Review Questions
      15. Critical Thinking Questions
    5. 26 Fluid, Electrolyte, and Acid-Base Balance
      1. Introduction
      2. 26.1 Body Fluids and Fluid Compartments
      3. 26.2 Water Balance
      4. 26.3 Electrolyte Balance
      5. 26.4 Acid-Base Balance
      6. 26.5 Disorders of Acid-Base Balance
      7. Key Terms
      8. Chapter Review
      9. Interactive Link Questions
      10. Review Questions
      11. Critical Thinking Questions
  7. Unit 6: Human Development and the Continuity of Life
    1. 27 The Reproductive System
      1. Introduction
      2. 27.1 Anatomy and Physiology of the Male Reproductive System
      3. 27.2 Anatomy and Physiology of the Female Reproductive System
      4. 27.3 Development of the Male and Female Reproductive Systems
      5. Key Terms
      6. Chapter Review
      7. Interactive Link Questions
      8. Review Questions
      9. Critical Thinking Questions
    2. 28 Development and Inheritance
      1. Introduction
      2. 28.1 Fertilization
      3. 28.2 Embryonic Development
      4. 28.3 Fetal Development
      5. 28.4 Maternal Changes During Pregnancy, Labor, and Birth
      6. 28.5 Adjustments of the Infant at Birth and Postnatal Stages
      7. 28.6 Lactation
      8. 28.7 Patterns of Inheritance
      9. Key Terms
      10. Chapter Review
      11. Interactive Link Questions
      12. Review Questions
      13. Critical Thinking Questions
  8. References
  9. Index
alkaloid
substance, usually from a plant source, that is chemically basic with respect to pH and will stimulate bitter receptors
amacrine cell
type of cell in the retina that connects to the bipolar cells near the outer synaptic layer and provides the basis for early image processing within the retina
ampulla
in the ear, the structure at the base of a semicircular canal that contains the hair cells and cupula for transduction of rotational movement of the head
anosmia
loss of the sense of smell; usually the result of physical disruption of the first cranial nerve
anterior corticospinal tract
division of the corticospinal pathway that travels through the ventral (anterior) column of the spinal cord and controls axial musculature through the medial motor neurons in the ventral (anterior) horn
aqueous humor
watery fluid that fills the anterior chamber containing the cornea, iris, ciliary body, and lens of the eye
ascending pathway
fiber structure that relays sensory information from the periphery through the spinal cord and brain stem to other structures of the brain
association area
region of cortex connected to a primary sensory cortical area that further processes the information to generate more complex sensory perceptions
audition
sense of hearing
auricle
fleshy external structure of the ear
basilar membrane
in the ear, the floor of the cochlear duct on which the organ of Corti sits
Betz cells
output cells of the primary motor cortex that cause musculature to move through synapses on cranial and spinal motor neurons
binocular depth cues
indications of the distance of visual stimuli on the basis of slight differences in the images projected onto either retina
bipolar cell
cell type in the retina that connects the photoreceptors to the RGCs
Broca’s area
region of the frontal lobe associated with the motor commands necessary for speech production
capsaicin
molecule that activates nociceptors by interacting with a temperature-sensitive ion channel and is the basis for “hot” sensations in spicy food
cerebral peduncles
segments of the descending motor pathway that make up the white matter of the ventral midbrain
cervical enlargement
region of the ventral (anterior) horn of the spinal cord that has a larger population of motor neurons for the greater number of and finer control of muscles of the upper limb
chemoreceptor
sensory receptor cell that is sensitive to chemical stimuli, such as in taste, smell, or pain
chief sensory nucleus
component of the trigeminal nuclei that is found in the pons
choroid
highly vascular tissue in the wall of the eye that supplies the outer retina with blood
ciliary body
smooth muscle structure on the interior surface of the iris that controls the shape of the lens through the zonule fibers
circadian rhythm
internal perception of the daily cycle of light and dark based on retinal activity related to sunlight
cochlea
auditory portion of the inner ear containing structures to transduce sound stimuli
cochlear duct
space within the auditory portion of the inner ear that contains the organ of Corti and is adjacent to the scala tympani and scala vestibuli on either side
cone photoreceptor
one of the two types of retinal receptor cell that is specialized for color vision through the use of three photopigments distributed through three separate populations of cells
contralateral
word meaning “on the opposite side,” as in axons that cross the midline in a fiber tract
cornea
fibrous covering of the anterior region of the eye that is transparent so that light can pass through it
corneal reflex
protective response to stimulation of the cornea causing contraction of the orbicularis oculi muscle resulting in blinking of the eye
corticobulbar tract
connection between the cortex and the brain stem responsible for generating movement
corticospinal tract
connection between the cortex and the spinal cord responsible for generating movement
cupula
specialized structure within the base of a semicircular canal that bends the stereocilia of hair cells when the head rotates by way of the relative movement of the enclosed fluid
decussate
to cross the midline, as in fibers that project from one side of the body to the other
dorsal column system
ascending tract of the spinal cord associated with fine touch and proprioceptive sensations
dorsal stream
connections between cortical areas from the occipital to parietal lobes that are responsible for the perception of visual motion and guiding movement of the body in relation to that motion
encapsulated ending
configuration of a sensory receptor neuron with dendrites surrounded by specialized structures to aid in transduction of a particular type of sensation, such as the lamellated corpuscles in the deep dermis and subcutaneous tissue
equilibrium
sense of balance that includes sensations of position and movement of the head
executive functions
cognitive processes of the prefrontal cortex that lead to directing goal-directed behavior, which is a precursor to executing motor commands
external ear
structures on the lateral surface of the head, including the auricle and the ear canal back to the tympanic membrane
exteroceptor
sensory receptor that is positioned to interpret stimuli from the external environment, such as photoreceptors in the eye or somatosensory receptors in the skin
extraocular muscle
one of six muscles originating out of the bones of the orbit and inserting into the surface of the eye which are responsible for moving the eye
extrapyramidal system
pathways between the brain and spinal cord that are separate from the corticospinal tract and are responsible for modulating the movements generated through that primary pathway
fasciculus cuneatus
lateral division of the dorsal column system composed of fibers from sensory neurons in the upper body
fasciculus gracilis
medial division of the dorsal column system composed of fibers from sensory neurons in the lower body
fibrous tunic
outer layer of the eye primarily composed of connective tissue known as the sclera and cornea
fovea
exact center of the retina at which visual stimuli are focused for maximal acuity, where the retina is thinnest, at which there is nothing but photoreceptors
free nerve ending
configuration of a sensory receptor neuron with dendrites in the connective tissue of the organ, such as in the dermis of the skin, that are most often sensitive to chemical, thermal, and mechanical stimuli
frontal eye fields
area of the prefrontal cortex responsible for moving the eyes to attend to visual stimuli
general sense
any sensory system that is distributed throughout the body and incorporated into organs of multiple other systems, such as the walls of the digestive organs or the skin
gustation
sense of taste
gustatory receptor cells
sensory cells in the taste bud that transduce the chemical stimuli of gustation
hair cells
mechanoreceptor cells found in the inner ear that transduce stimuli for the senses of hearing and balance
incus
(also, anvil) ossicle of the middle ear that connects the malleus to the stapes
inferior colliculus
last structure in the auditory brainstem pathway that projects to the thalamus and superior colliculus
inferior oblique
extraocular muscle responsible for lateral rotation of the eye
inferior rectus
extraocular muscle responsible for looking down
inner ear
structure within the temporal bone that contains the sensory apparati of hearing and balance
inner segment
in the eye, the section of a photoreceptor that contains the nucleus and other major organelles for normal cellular functions
inner synaptic layer
layer in the retina where bipolar cells connect to RGCs
interaural intensity difference
cue used to aid sound localization in the horizontal plane that compares the relative loudness of sounds at the two ears, because the ear closer to the sound source will hear a slightly more intense sound
interaural time difference
cue used to help with sound localization in the horizontal plane that compares the relative time of arrival of sounds at the two ears, because the ear closer to the sound source will receive the stimulus microseconds before the other ear
internal capsule
segment of the descending motor pathway that passes between the caudate nucleus and the putamen
interoceptor
sensory receptor that is positioned to interpret stimuli from internal organs, such as stretch receptors in the wall of blood vessels
ipsilateral
word meaning on the same side, as in axons that do not cross the midline in a fiber tract
iris
colored portion of the anterior eye that surrounds the pupil
kinesthesia
sense of body movement based on sensations in skeletal muscles, tendons, joints, and the skin
lacrimal duct
duct in the medial corner of the orbit that drains tears into the nasal cavity
lacrimal gland
gland lateral to the orbit that produces tears to wash across the surface of the eye
lateral corticospinal tract
division of the corticospinal pathway that travels through the lateral column of the spinal cord and controls appendicular musculature through the lateral motor neurons in the ventral (anterior) horn
lateral geniculate nucleus
thalamic target of the RGCs that projects to the visual cortex
lateral rectus
extraocular muscle responsible for abduction of the eye
lens
component of the eye that focuses light on the retina
levator palpebrae superioris
muscle that causes elevation of the upper eyelid, controlled by fibers in the oculomotor nerve
lumbar enlargement
region of the ventral (anterior) horn of the spinal cord that has a larger population of motor neurons for the greater number of muscles of the lower limb
macula
enlargement at the base of a semicircular canal at which transduction of equilibrium stimuli takes place within the ampulla
malleus
(also, hammer) ossicle that is directly attached to the tympanic membrane
mechanoreceptor
receptor cell that transduces mechanical stimuli into an electrochemical signal
medial geniculate nucleus
thalamic target of the auditory brain stem that projects to the auditory cortex
medial lemniscus
fiber tract of the dorsal column system that extends from the nuclei gracilis and cuneatus to the thalamus, and decussates
medial rectus
extraocular muscle responsible for adduction of the eye
mesencephalic nucleus
component of the trigeminal nuclei that is found in the midbrain
middle ear
space within the temporal bone between the ear canal and bony labyrinth where the ossicles amplify sound waves from the tympanic membrane to the oval window
multimodal integration area
region of the cerebral cortex in which information from more than one sensory modality is processed to arrive at higher level cortical functions such as memory, learning, or cognition
neural tunic
layer of the eye that contains nervous tissue, namely the retina
nociceptor
receptor cell that senses pain stimuli
nucleus cuneatus
medullary nucleus at which first-order neurons of the dorsal column system synapse specifically from the upper body and arms
nucleus gracilis
medullary nucleus at which first-order neurons of the dorsal column system synapse specifically from the lower body and legs
odorant molecules
volatile chemicals that bind to receptor proteins in olfactory neurons to stimulate the sense of smell
olfaction
sense of smell
olfactory bulb
central target of the first cranial nerve; located on the ventral surface of the frontal lobe in the cerebrum
olfactory epithelium
region of the nasal epithelium where olfactory neurons are located
olfactory sensory neuron
receptor cell of the olfactory system, sensitive to the chemical stimuli of smell, the axons of which compose the first cranial nerve
opsin
protein that contains the photosensitive cofactor retinal for phototransduction
optic chiasm
decussation point in the visual system at which medial retina fibers cross to the other side of the brain
optic disc
spot on the retina at which RGC axons leave the eye and blood vessels of the inner retina pass
optic nerve
second cranial nerve, which is responsible visual sensation
optic tract
name for the fiber structure containing axons from the retina posterior to the optic chiasm representing their CNS location
organ of Corti
structure in the cochlea in which hair cells transduce movements from sound waves into electrochemical signals
osmoreceptor
receptor cell that senses differences in the concentrations of bodily fluids on the basis of osmotic pressure
ossicles
three small bones in the middle ear
otolith
layer of calcium carbonate crystals located on top of the otolithic membrane
otolithic membrane
gelatinous substance in the utricle and saccule of the inner ear that contains calcium carbonate crystals and into which the stereocilia of hair cells are embedded
outer segment
in the eye, the section of a photoreceptor that contains opsin molecules that transduce light stimuli
outer synaptic layer
layer in the retina at which photoreceptors connect to bipolar cells
oval window
membrane at the base of the cochlea where the stapes attaches, marking the beginning of the scala vestibuli
palpebral conjunctiva
membrane attached to the inner surface of the eyelids that covers the anterior surface of the cornea
papilla
for gustation, a bump-like projection on the surface of the tongue that contains taste buds
photoisomerization
chemical change in the retinal molecule that alters the bonding so that it switches from the 11-cis-retinal isomer to the all-trans-retinal isomer
photon
individual “packet” of light
photoreceptor
receptor cell specialized to respond to light stimuli
premotor cortex
cortical area anterior to the primary motor cortex that is responsible for planning movements
primary sensory cortex
region of the cerebral cortex that initially receives sensory input from an ascending pathway from the thalamus and begins the processing that will result in conscious perception of that modality
proprioception
sense of position and movement of the body
proprioceptor
receptor cell that senses changes in the position and kinesthetic aspects of the body
pupil
open hole at the center of the iris that light passes through into the eye
pyramidal decussation
location at which corticospinal tract fibers cross the midline and segregate into the anterior and lateral divisions of the pathway
pyramids
segment of the descending motor pathway that travels in the anterior position of the medulla
receptor cell
cell that transduces environmental stimuli into neural signals
red nucleus
midbrain nucleus that sends corrective commands to the spinal cord along the rubrospinal tract, based on disparity between an original command and the sensory feedback from movement
reticulospinal tract
extrapyramidal connections between the brain stem and spinal cord that modulate movement, contribute to posture, and regulate muscle tone
retina
nervous tissue of the eye at which phototransduction takes place
retinal
cofactor in an opsin molecule that undergoes a biochemical change when struck by a photon (pronounced with a stress on the last syllable)
retinal ganglion cell (RGC)
neuron of the retina that projects along the second cranial nerve
rhodopsin
photopigment molecule found in the rod photoreceptors
rod photoreceptor
one of the two types of retinal receptor cell that is specialized for low-light vision
round window
membrane that marks the end of the scala tympani
rubrospinal tract
descending motor control pathway, originating in the red nucleus, that mediates control of the limbs on the basis of cerebellar processing
saccule
structure of the inner ear responsible for transducing linear acceleration in the vertical plane
scala tympani
portion of the cochlea that extends from the apex to the round window
scala vestibuli
portion of the cochlea that extends from the oval window to the apex
sclera
white of the eye
semicircular canals
structures within the inner ear responsible for transducing rotational movement information
sensory homunculus
topographic representation of the body within the somatosensory cortex demonstrating the correspondence between neurons processing stimuli and sensitivity
sensory modality
a particular system for interpreting and perceiving environmental stimuli by the nervous system
solitary nucleus
medullar nucleus that receives taste information from the facial and glossopharyngeal nerves
somatosensation
general sense associated with modalities lumped together as touch
special sense
any sensory system associated with a specific organ structure, namely smell, taste, sight, hearing, and balance
spinal trigeminal nucleus
component of the trigeminal nuclei that is found in the medulla
spinothalamic tract
ascending tract of the spinal cord associated with pain and temperature sensations
spiral ganglion
location of neuronal cell bodies that transmit auditory information along the eighth cranial nerve
stapes
(also, stirrup) ossicle of the middle ear that is attached to the inner ear
stereocilia
array of apical membrane extensions in a hair cell that transduce movements when they are bent
stretch reflex
response to activation of the muscle spindle stretch receptor that causes contraction of the muscle to maintain a constant length
submodality
specific sense within a broader major sense such as sweet as a part of the sense of taste, or color as a part of vision
superior colliculus
structure in the midbrain that combines visual, auditory, and somatosensory input to coordinate spatial and topographic representations of the three sensory systems
superior oblique
extraocular muscle responsible for medial rotation of the eye
superior rectus
extraocular muscle responsible for looking up
supplemental motor area
cortical area anterior to the primary motor cortex that is responsible for planning movements
suprachiasmatic nucleus
hypothalamic target of the retina that helps to establish the circadian rhythm of the body on the basis of the presence or absence of daylight
taste buds
structures within a papilla on the tongue that contain gustatory receptor cells
tectorial membrane
component of the organ of Corti that lays over the hair cells, into which the stereocilia are embedded
tectospinal tract
extrapyramidal connections between the superior colliculus and spinal cord
thermoreceptor
sensory receptor specialized for temperature stimuli
topographical
relating to positional information
transduction
process of changing an environmental stimulus into the electrochemical signals of the nervous system
trochlea
cartilaginous structure that acts like a pulley for the superior oblique muscle
tympanic membrane
ear drum
umami
taste submodality for sensitivity to the concentration of amino acids; also called the savory sense
utricle
structure of the inner ear responsible for transducing linear acceleration in the horizontal plane
vascular tunic
middle layer of the eye primarily composed of connective tissue with a rich blood supply
ventral posterior nucleus
nucleus in the thalamus that is the target of gustatory sensations and projects to the cerebral cortex
ventral stream
connections between cortical areas from the occipital lobe to the temporal lobe that are responsible for identification of visual stimuli
vestibular ganglion
location of neuronal cell bodies that transmit equilibrium information along the eighth cranial nerve
vestibular nuclei
targets of the vestibular component of the eighth cranial nerve
vestibule
in the ear, the portion of the inner ear responsible for the sense of equilibrium
vestibulo-ocular reflex (VOR)
reflex based on connections between the vestibular system and the cranial nerves of eye movements that ensures images are stabilized on the retina as the head and body move
vestibulospinal tract
extrapyramidal connections between the vestibular nuclei in the brain stem and spinal cord that modulate movement and contribute to balance on the basis of the sense of equilibrium
visceral sense
sense associated with the internal organs
vision
special sense of sight based on transduction of light stimuli
visual acuity
property of vision related to the sharpness of focus, which varies in relation to retinal position
vitreous humor
viscous fluid that fills the posterior chamber of the eye
working memory
function of the prefrontal cortex to maintain a representation of information that is not in the immediate environment
zonule fibers
fibrous connections between the ciliary body and the lens
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