Free nerve endings are the simplest sensory receptors located throughout the body and skin. They detect sensations like pain, touch, heat and cold. Other receptor types include Merkel disks for light touch, Meissner corpuscles for vibration, and muscle spindles and Golgi tendon organs in muscles and tendons that provide information on movement and positioning. The eye contains receptors for vision, with the retina containing rods and cones that detect light as the visual photoreceptors. Other receptors in the body are classified as exteroceptors on the skin, visceroceptors inside organs, and proprioceptors in muscles, tendons and joints.
The document describes the different types of tissues in the human body, including epithelial tissues (simple squamous, stratified squamous, etc.), connective tissues (blood, cartilage, bone), muscular tissues (skeletal, smooth, cardiac), nervous tissues, and special tissues. It provides the location and function of each tissue type. The various tissue types each have a specific microscopic structure and play an important role in the structure and functioning of the human body.
Symantec AntiVirus provides virus and security risk protection for computers. It can detect and remove viruses, worms, trojans, and other security risks. Symantec AntiVirus keeps protection current through automatic updates that are delivered via LiveUpdate. This helps ensure computers are protected from the latest viruses and security risks.
The document describes the different types of human tissues, including epithelial tissues (simple squamous, stratified squamous, etc.), connective tissues (blood, cartilage, bone), muscular tissues (skeletal, smooth, cardiac), nervous tissues, and their locations and functions in the human body. A total of 17 different tissue types are defined along with their characteristic structures, locations within the body, and physiological roles.
The plasma membrane forms the boundary of the cell. The cell's power plant is the organelle that produces energy for the cell. Cells require water to survive, as it makes up almost 70% of body weight and is the cradle of life.
Future Selling in B2B Media: Yes, There is a FutureBusiness.com
Business.com CEO Tony Uphoff's presentation from the Business Information & Media Summit held by ABM, SIPA, and SIIA in partnership with infocommerce about marketing automation, programmatic buying and retargeting.
The Engineering Services Team is comprised of experienced professionals who support the automotive industry by helping to ensure projects are completed on time and meet quality standards. They have experience leading successful projects for Tier 1 and Tier 2 suppliers and OEMs. Services include liaison support, project engineering, measurement and metrology, inspection, sorting, containment, rework, and transportation. The team also offers supplier development, quality skills training, and leadership development. Team members are based in Mexico and the United States.
This document describes an experiment that measures heart rate and blood pressure in response to cold stimulus. Baseline heart rate and blood pressure are recorded before immersing a foot in ice water. Immersion causes heart rate and blood pressure to increase through activation of the sympathetic nervous system. After removal from the cold, heart rate decreases but remains elevated before gradually returning to baseline. The experiment demonstrates how vital signs change during sympathetic nervous system activation in a "fight or flight" response.
The document describes the different types of tissues in the human body, including epithelial tissues (simple squamous, stratified squamous, etc.), connective tissues (blood, cartilage, bone), muscular tissues (skeletal, smooth, cardiac), nervous tissues, and special tissues. It provides the location and function of each tissue type. The various tissue types each have a specific microscopic structure and play an important role in the structure and functioning of the human body.
Symantec AntiVirus provides virus and security risk protection for computers. It can detect and remove viruses, worms, trojans, and other security risks. Symantec AntiVirus keeps protection current through automatic updates that are delivered via LiveUpdate. This helps ensure computers are protected from the latest viruses and security risks.
The document describes the different types of human tissues, including epithelial tissues (simple squamous, stratified squamous, etc.), connective tissues (blood, cartilage, bone), muscular tissues (skeletal, smooth, cardiac), nervous tissues, and their locations and functions in the human body. A total of 17 different tissue types are defined along with their characteristic structures, locations within the body, and physiological roles.
The plasma membrane forms the boundary of the cell. The cell's power plant is the organelle that produces energy for the cell. Cells require water to survive, as it makes up almost 70% of body weight and is the cradle of life.
Future Selling in B2B Media: Yes, There is a FutureBusiness.com
Business.com CEO Tony Uphoff's presentation from the Business Information & Media Summit held by ABM, SIPA, and SIIA in partnership with infocommerce about marketing automation, programmatic buying and retargeting.
The Engineering Services Team is comprised of experienced professionals who support the automotive industry by helping to ensure projects are completed on time and meet quality standards. They have experience leading successful projects for Tier 1 and Tier 2 suppliers and OEMs. Services include liaison support, project engineering, measurement and metrology, inspection, sorting, containment, rework, and transportation. The team also offers supplier development, quality skills training, and leadership development. Team members are based in Mexico and the United States.
This document describes an experiment that measures heart rate and blood pressure in response to cold stimulus. Baseline heart rate and blood pressure are recorded before immersing a foot in ice water. Immersion causes heart rate and blood pressure to increase through activation of the sympathetic nervous system. After removal from the cold, heart rate decreases but remains elevated before gradually returning to baseline. The experiment demonstrates how vital signs change during sympathetic nervous system activation in a "fight or flight" response.
This document contains 5 articles that discuss various topics related to human sensory systems and vision. Article 1 defines and describes different types of sensory receptors in the body. Article 2 discusses the senses of smell, taste, and hearing. Article 3 further explains different categories of sensory receptors. Article 4 provides details about the visual process including refraction, accommodation, pupil constriction, convergence, and discusses near- and farsightedness. Article 5 is incomplete.
This 3-sentence summary provides the key information from the document:
The document discusses different types of sensory receptors in the human body, including exteroceptors, proprioceptors, thermoreceptors, photoreceptors, and nociceptors. It explains what stimuli each receptor type responds to, such as touch, temperature, light, and pain. The summary also mentions the retina contains rods and cones that contain photopigments like rhodopsin to detect light and allow for vision.
This document discusses sensory receptors and how they function during the Christmas holiday season. It provides examples of how sensory receptors detect stimuli like hunger cues from cookies left out for Santa, different moods conveyed through Christmas versus Halloween songs, and sensations like pain experienced by characters in Christmas movies. The document then explores the anatomy and physiology of various sensory receptors, including their location, structure, and role in senses like smell, taste, hearing, vision, balance and proprioception.
This document summarizes the somatosensory system and receptors. It describes the different types of sensation including superficial, deep, visceral, and special. It outlines the categories of conscious and non-conscious sensation. It discusses the different receptors including exteroceptors, proprioceptors, and intteroceptors. It details the nerve endings including free nerve endings, follicular nerve endings, Merkel cell neurite complexes, encapsulated endings like Meissner's corpuscles and Pacinian corpuscles. It outlines the somatosensory pathways including the posterior column-medial lemniscal pathway and spinothalamic pathway.
1. The document provides an in-depth look at the nervous system through recipes related to sensory receptors and special senses.
2. It details the various types of sensory receptors, including their locations, stimuli detected, and structures. It also examines the special senses of smell, taste, hearing, balance, and vision.
3. The recipes describe the key components and processes of each sensory system, such as olfactory receptors and pathways for smell, taste buds and neural pathways for taste, and the mechanism of hearing and visual pathway.
1. The document provides an in-depth look at the nervous system through recipes related to sensory receptors and special senses.
2. It details the various types of sensory receptors, including their locations, stimuli detected, and structures. It also examines the special senses of smell, taste, hearing, balance, and vision.
3. The recipes describe the key components and processes of each sensory system, such as olfactory receptors and pathways for smell, taste buds and neural pathways for taste, and the mechanism of hearing and visual pathway.
This document discusses the human sensory systems. It describes four types of sensations - superficial, deep, visceral, and special. It then provides details on the receptors, pathways, and neural connections involved in touch, pain, temperature, proprioception, and other senses. Specifically, it outlines the locations and functions of mechanoreceptors like Meissner's corpuscles and Merkel endings, as well as nociceptors that detect pain. It also compares the dorsal column-medial lemniscus pathway and spinothalamic tract, noting their roles in transmitting different sensory signals to the cortex.
The document discusses the anatomy and function of the spinal cord and spinal nerves. It begins by describing the gross anatomy of the spinal cord, including the 31 pairs of spinal nerves and their numbering. It then discusses the functional organization of the spinal cord gray matter into dorsal, lateral, and ventral horns that contain sensory and motor nuclei. The document also describes the monosynaptic and polysynaptic reflex arcs in the spinal cord that underlie reflexes like the stretch reflex. It concludes by discussing spinal nerve structure and the dermatomal distribution of cutaneous innervation.
This document discusses different types of sensory receptors in the human body. It describes exteroceptors, which receive external stimuli from areas like the skin, and visceroreceptors, located in internal organs. It also discusses proprioceptors, which provide information about body position and movement. It then explains different categories of receptors based on what they detect, such as mechanoreceptors for touch and pressure, chemoreceptors for chemicals, thermoreceptors for temperature, and photoreceptors for light. The document also mentions nociceptors, which detect potentially painful stimuli.
The sensory organs detect stimuli from the environment and transmit this information to the brain. The main sensory organs are the eyes, ears, nose, tongue and skin. The eyes detect light, ears detect sound, nose detects smell, tongue detects taste and skin detects touch, pressure, temperature and pain. Within each sensory organ are specialized receptor cells that detect specific stimuli like light, sound, chemicals etc. The stimuli are converted to electrical signals that travel along sensory nerves to the brain which interprets these signals as the different senses.
Animals have developed specialized sensory organs like eyes and ears to actively seek information from the environment. These organs evolved to help detect things like food from a distance. The eye detects light and vision, while the ear detects sound and hearing. Both eyes and ears have complex structures that are finely tuned to receive and process sensory inputs. The eye contains light-sensitive rods and cones in the retina to detect color and vision. The ear detects sound waves through the outer, middle, and inner ear structures that funnel and amplify sound before vibrations are converted to nerve signals. These special senses allow animals to effectively interact with their surroundings.
The document provides an overview of human perception and the processes involved. It discusses sensation, which is the detection of stimulus energies by sensory receptors. Perception is then defined as the interpretation and organization of sensory information. The key stages of perception are transduction, neural transmission along afferent pathways to the brain, and cognitive processing in the brain. The various sensory receptors for sight, sound, touch, taste and smell are described.
This document provides information on sensory receptors and the structures involved in the special senses of smell, taste, hearing, and balance. It discusses the types of sensory receptors, their locations and functions. It also describes the neural pathways and mechanisms for each special sense. Key structures are defined for smell (olfactory epithelium, receptors), taste (taste buds, papillae), hearing (external, middle, inner ear structures) and balance (utricle, saccule, semicircular canals).
This document provides information on sensory receptors and the structures involved in the special senses of smell, taste, hearing, and balance. It discusses the main types of sensory receptors, including mechanoreceptors, photoreceptors, chemoreceptors, thermoreceptors, and nociceptors. It then describes the structures of sensory organs like muscle spindles, Meissner corpuscles, Pacinian corpuscles, Merkel disks, and Golgi tendon organs. The following sections focus on the special senses, outlining the neural pathways and mechanisms of smell, taste, hearing, and the roles of the inner ear in balance.
The document summarizes the key differences between the somatic and autonomic nervous systems. The somatic nervous system includes sensory and motor neurons that allow for voluntary movement and conscious perception of senses. The autonomic nervous system unconsciously regulates internal organs and glands and has sympathetic ("fight or flight") and parasympathetic ("rest and digest") divisions. It also reviews the different sensory systems like vision, hearing, smell, taste and touch, and the receptors and pathways involved.
The document discusses how CieAura Transparent Holographic Chips influence human health by stimulating acupuncture points and energy flows called meridians. It explains that the chips contain vibrations programmed using VibraTec technology that are released by the body's energy field to influence key points. The chips provide a unique and safe way to balance the body's inner energy without anything entering the body. The document also outlines four premises for how the chips work by modifying internal vibrations through external vibration sources.
This document discusses receptors and neurons that detect sensory information. It begins by defining perception and describing how sensory information is transmitted from receptors to the central nervous system. It then categorizes the different sensory modalities like touch, pain, temperature, and proprioception. The document goes on to describe the different types of sensory receptors, including their locations, the stimuli they detect, and whether they adapt rapidly or slowly. It provides examples of specific receptors like Meissner corpuscles, Pacinian corpuscles, and thermoreceptors. In closing, it notes the uneven distribution of receptors in the skin and modalities detected in the skin.
This document discusses sensory receptors, including their types, structures, and functions. It covers exteroceptors, visceroceptors, proprioceptors, mechanoreceptors, chemoreceptors, thermoreceptors, nociceptors, photoreceptors, olfactory receptors, taste receptors, hearing receptors, and balance receptors. Key points include that sensory receptors receive stimuli from both internal and external environments and relay this information to the nervous system, and that different receptor types are activated by mechanical, chemical, thermal, or light stimuli.
The document summarizes key aspects of the nervous system including its organization, cells, nerve impulses, synapses, and reflexes. It describes the central and peripheral nervous systems, types of neurons, action potentials, and synaptic transmission. It also presents data from a neuromuscular reflex lab experiment showing involuntary reflexes have faster reaction times than voluntary movements.
This document discusses lung volumes and capacities, including tidal volume, inspiratory reserve volume, expiratory reserve volume, vital capacity, residual volume, total lung capacity, and minute ventilation. It provides definitions and normal ranges for these measurements and describes how they are obtained through spirometry. The objectives are to obtain graphical representations of lung volumes, compare volumes between males and females, and correlate volumes with clinical conditions like fibrosis and emphysema.
This document analyzes blood typing results from 4 patients and asks the reader to answer questions about blood types and compatibility. Table 1 shows the results of blood serum tests for the 4 patients, identifying their blood types as A+, B-, AB+, and O-. Subsequent questions ask the reader to determine blood type compatibility for transfusions based on these results, compare features of agglutinogens and agglutinins, describe how blood typing is performed, and discuss uses and safety considerations for blood typing.
This document contains 5 articles that discuss various topics related to human sensory systems and vision. Article 1 defines and describes different types of sensory receptors in the body. Article 2 discusses the senses of smell, taste, and hearing. Article 3 further explains different categories of sensory receptors. Article 4 provides details about the visual process including refraction, accommodation, pupil constriction, convergence, and discusses near- and farsightedness. Article 5 is incomplete.
This 3-sentence summary provides the key information from the document:
The document discusses different types of sensory receptors in the human body, including exteroceptors, proprioceptors, thermoreceptors, photoreceptors, and nociceptors. It explains what stimuli each receptor type responds to, such as touch, temperature, light, and pain. The summary also mentions the retina contains rods and cones that contain photopigments like rhodopsin to detect light and allow for vision.
This document discusses sensory receptors and how they function during the Christmas holiday season. It provides examples of how sensory receptors detect stimuli like hunger cues from cookies left out for Santa, different moods conveyed through Christmas versus Halloween songs, and sensations like pain experienced by characters in Christmas movies. The document then explores the anatomy and physiology of various sensory receptors, including their location, structure, and role in senses like smell, taste, hearing, vision, balance and proprioception.
This document summarizes the somatosensory system and receptors. It describes the different types of sensation including superficial, deep, visceral, and special. It outlines the categories of conscious and non-conscious sensation. It discusses the different receptors including exteroceptors, proprioceptors, and intteroceptors. It details the nerve endings including free nerve endings, follicular nerve endings, Merkel cell neurite complexes, encapsulated endings like Meissner's corpuscles and Pacinian corpuscles. It outlines the somatosensory pathways including the posterior column-medial lemniscal pathway and spinothalamic pathway.
1. The document provides an in-depth look at the nervous system through recipes related to sensory receptors and special senses.
2. It details the various types of sensory receptors, including their locations, stimuli detected, and structures. It also examines the special senses of smell, taste, hearing, balance, and vision.
3. The recipes describe the key components and processes of each sensory system, such as olfactory receptors and pathways for smell, taste buds and neural pathways for taste, and the mechanism of hearing and visual pathway.
1. The document provides an in-depth look at the nervous system through recipes related to sensory receptors and special senses.
2. It details the various types of sensory receptors, including their locations, stimuli detected, and structures. It also examines the special senses of smell, taste, hearing, balance, and vision.
3. The recipes describe the key components and processes of each sensory system, such as olfactory receptors and pathways for smell, taste buds and neural pathways for taste, and the mechanism of hearing and visual pathway.
This document discusses the human sensory systems. It describes four types of sensations - superficial, deep, visceral, and special. It then provides details on the receptors, pathways, and neural connections involved in touch, pain, temperature, proprioception, and other senses. Specifically, it outlines the locations and functions of mechanoreceptors like Meissner's corpuscles and Merkel endings, as well as nociceptors that detect pain. It also compares the dorsal column-medial lemniscus pathway and spinothalamic tract, noting their roles in transmitting different sensory signals to the cortex.
The document discusses the anatomy and function of the spinal cord and spinal nerves. It begins by describing the gross anatomy of the spinal cord, including the 31 pairs of spinal nerves and their numbering. It then discusses the functional organization of the spinal cord gray matter into dorsal, lateral, and ventral horns that contain sensory and motor nuclei. The document also describes the monosynaptic and polysynaptic reflex arcs in the spinal cord that underlie reflexes like the stretch reflex. It concludes by discussing spinal nerve structure and the dermatomal distribution of cutaneous innervation.
This document discusses different types of sensory receptors in the human body. It describes exteroceptors, which receive external stimuli from areas like the skin, and visceroreceptors, located in internal organs. It also discusses proprioceptors, which provide information about body position and movement. It then explains different categories of receptors based on what they detect, such as mechanoreceptors for touch and pressure, chemoreceptors for chemicals, thermoreceptors for temperature, and photoreceptors for light. The document also mentions nociceptors, which detect potentially painful stimuli.
The sensory organs detect stimuli from the environment and transmit this information to the brain. The main sensory organs are the eyes, ears, nose, tongue and skin. The eyes detect light, ears detect sound, nose detects smell, tongue detects taste and skin detects touch, pressure, temperature and pain. Within each sensory organ are specialized receptor cells that detect specific stimuli like light, sound, chemicals etc. The stimuli are converted to electrical signals that travel along sensory nerves to the brain which interprets these signals as the different senses.
Animals have developed specialized sensory organs like eyes and ears to actively seek information from the environment. These organs evolved to help detect things like food from a distance. The eye detects light and vision, while the ear detects sound and hearing. Both eyes and ears have complex structures that are finely tuned to receive and process sensory inputs. The eye contains light-sensitive rods and cones in the retina to detect color and vision. The ear detects sound waves through the outer, middle, and inner ear structures that funnel and amplify sound before vibrations are converted to nerve signals. These special senses allow animals to effectively interact with their surroundings.
The document provides an overview of human perception and the processes involved. It discusses sensation, which is the detection of stimulus energies by sensory receptors. Perception is then defined as the interpretation and organization of sensory information. The key stages of perception are transduction, neural transmission along afferent pathways to the brain, and cognitive processing in the brain. The various sensory receptors for sight, sound, touch, taste and smell are described.
This document provides information on sensory receptors and the structures involved in the special senses of smell, taste, hearing, and balance. It discusses the types of sensory receptors, their locations and functions. It also describes the neural pathways and mechanisms for each special sense. Key structures are defined for smell (olfactory epithelium, receptors), taste (taste buds, papillae), hearing (external, middle, inner ear structures) and balance (utricle, saccule, semicircular canals).
This document provides information on sensory receptors and the structures involved in the special senses of smell, taste, hearing, and balance. It discusses the main types of sensory receptors, including mechanoreceptors, photoreceptors, chemoreceptors, thermoreceptors, and nociceptors. It then describes the structures of sensory organs like muscle spindles, Meissner corpuscles, Pacinian corpuscles, Merkel disks, and Golgi tendon organs. The following sections focus on the special senses, outlining the neural pathways and mechanisms of smell, taste, hearing, and the roles of the inner ear in balance.
The document summarizes the key differences between the somatic and autonomic nervous systems. The somatic nervous system includes sensory and motor neurons that allow for voluntary movement and conscious perception of senses. The autonomic nervous system unconsciously regulates internal organs and glands and has sympathetic ("fight or flight") and parasympathetic ("rest and digest") divisions. It also reviews the different sensory systems like vision, hearing, smell, taste and touch, and the receptors and pathways involved.
The document discusses how CieAura Transparent Holographic Chips influence human health by stimulating acupuncture points and energy flows called meridians. It explains that the chips contain vibrations programmed using VibraTec technology that are released by the body's energy field to influence key points. The chips provide a unique and safe way to balance the body's inner energy without anything entering the body. The document also outlines four premises for how the chips work by modifying internal vibrations through external vibration sources.
This document discusses receptors and neurons that detect sensory information. It begins by defining perception and describing how sensory information is transmitted from receptors to the central nervous system. It then categorizes the different sensory modalities like touch, pain, temperature, and proprioception. The document goes on to describe the different types of sensory receptors, including their locations, the stimuli they detect, and whether they adapt rapidly or slowly. It provides examples of specific receptors like Meissner corpuscles, Pacinian corpuscles, and thermoreceptors. In closing, it notes the uneven distribution of receptors in the skin and modalities detected in the skin.
This document discusses sensory receptors, including their types, structures, and functions. It covers exteroceptors, visceroceptors, proprioceptors, mechanoreceptors, chemoreceptors, thermoreceptors, nociceptors, photoreceptors, olfactory receptors, taste receptors, hearing receptors, and balance receptors. Key points include that sensory receptors receive stimuli from both internal and external environments and relay this information to the nervous system, and that different receptor types are activated by mechanical, chemical, thermal, or light stimuli.
The document summarizes key aspects of the nervous system including its organization, cells, nerve impulses, synapses, and reflexes. It describes the central and peripheral nervous systems, types of neurons, action potentials, and synaptic transmission. It also presents data from a neuromuscular reflex lab experiment showing involuntary reflexes have faster reaction times than voluntary movements.
This document discusses lung volumes and capacities, including tidal volume, inspiratory reserve volume, expiratory reserve volume, vital capacity, residual volume, total lung capacity, and minute ventilation. It provides definitions and normal ranges for these measurements and describes how they are obtained through spirometry. The objectives are to obtain graphical representations of lung volumes, compare volumes between males and females, and correlate volumes with clinical conditions like fibrosis and emphysema.
This document analyzes blood typing results from 4 patients and asks the reader to answer questions about blood types and compatibility. Table 1 shows the results of blood serum tests for the 4 patients, identifying their blood types as A+, B-, AB+, and O-. Subsequent questions ask the reader to determine blood type compatibility for transfusions based on these results, compare features of agglutinogens and agglutinins, describe how blood typing is performed, and discuss uses and safety considerations for blood typing.
This document contains a blood typing analysis of 4 patients and questions related to blood typing. It discusses determining blood types through agglutination tests using anti-A, anti-B, and anti-Rh sera. It also covers blood type compatibility for transfusions and donations. Key points covered include the presence or absence of agglutinogens and agglutinins determining different blood types, situations where blood typing is important like transfusions and donations, and minimizing disease transmission in blood labs.
Osteoblasts form new bone tissue and regulate mineral deposition on bone surfaces. Osteoclasts degrade and resorb bone tissue. Osteocytes were formerly osteoblasts embedded in the bone matrix and communicate with other bone cells to regulate bone remodeling and respond to mechanical stresses on bones.
The document lists the results of three surveys asking people about characteristics of life, directional terms of the body, and anatomical plans of the body. The first survey shows the top 10 characteristics of life chosen by 100 people, with responsiveness being the most popular answer. The second survey displays the top 14 directional body terms selected by 100 people, with ventral being number one. The third survey presents the top 5 anatomical body plans voted on by 100 people, identifying the sagittal plan as the favorite.
1. Structure (5)
Christmas edition
Free nerve ending: simplest, most common sensory receptors
located on the surface of the body known as exteroceptors and
in internal organs known as visce receptors. Nociceptor are slen-
der sensory fibers that are responsible for pain. Brain tissue lack It’s beginning to look a lot like
free sensory nerve endings and are incapable of sensing painful Christmas, everywhere you go…
stimuli. Nerve endings are also responsible for sensation and (page 6)
touch and also sensations of heat cold. We’ll tell you how
Root hair plexuses: delicate, web-like arrangements of free to spot some
nerve endings that surround hair follicles that can detect any great deals with
type of hair movement. the help of your
Merkel disks: disc-shaped or flattened and are responsible for vision! (Page 2-3)
mediating sensations of light or discriminative touch that is lo- The minty smell of
cated on the surface of the skin. (21)
that peppermint
Meissner Corpuscle: when “deformed” by a mechanical type of candle… ah, it’s the
stimulus, this type of receptor, sometimes called a tactile corpus- smell of Christmas.
cle, mediates sensations of discriminative touch and low- (page 7-8)
frequency vibration. (especially numerous in hairless skin areas,
such as the nipples, fingertips, and lips)
Pacinian Corpuscles: large mechanoreceptors, which when sec- We all love the
tioned, show thick laminated connective tissue capsules. (found cinnamon taste of
in deep dermis of the skin-especially in the hands and feet-and snickerdoodle
are also numerous in joint capsules throughout the body). cookies! (page 10-
Muscle Spindles- the most important stretch receptors are asso- 11)
ciated with muscles and tendons and are classified as proprio-
ceptors. Two types of stretch receptors, called muscle spindles
and golgi tendon receptors, operate to provide the body with
information concerning muscle length and the strength of mus-
How are we able to see all the
cle contraction. (the result of stimulation is a stretch reflex that Remember to keep your bright Christmas lights? We’ll
shortens a muscle or muscle group, thus aiding in the mainte- balance while hanging tell you how! (page 4-5)
nance of posture or the positioning of the body or one of its ex- up your Christmas
tremities in a way that may be opposed by the force of gravity). lights! (page 9)
Golgi tendon Organs- like muscle spindles, are proprioceptors.
They are located at the point of junction between muscle tissue Also in this issue...
and tendon. These receptors act in a way opposite that of mus- • Locations of receptors……………………….……page 12
cle spindles.
• Stimulus detected…………………………………..page 13
• Structure……………………………………………….page 14
2. HOW TO SPOT KILLER DEALS Stimulus Detected (5)
With the help of your vision
Page 2 Page 13
(25)
Mechanoreceptors: are activated by mechanical stimuli that in
some way “deform” or change the position of the receptor, re-
sulting in the generation of a receptor potential. Examples of this
is pressure applied to the skin or to blood vessels, or cause by
stretch or pressure in the muscle, tendon, or lung tissue.
Chemoreceptors: activated by either the amount or the changing
concentration of certain chemicals. Examples are our senses of
taste and smell depend on these.
Thermoreceptors: activated by change in temperature. Examples
are when the outside temperature is colder than your body; your
brain tells your body to warm up.
Your vision plays an important part when spotting some Nociceptors: the relatively unspecialized nerve cell endings that
good deals. There are 3 layers of tissue that compose the eyeball: initiate the sensation of pain are called Nociceptors. They trans-
the sclera (a tough outer coat), the cornea (the transparent anteri- duce a variety of stimuli into receptor potentials, which in turn
or portion that lies over the iris), and the canal of schlemm (a ring- trigger afferent action potentials. They arise from cell bodies in
shaped venous sinus found deep within the anterior portion of the dorsal root ganglia that send one axonal process to the periphery
sclera). and the other into the spinal cord or brainstem. (20)
The choroid is the middle coat of the eye and it contains Photoreceptors: the retina is the back part of the eye that con-
many blood vessels and a large amount of pigment . The ciliary tains the cells that respond to light. These specialized cells are
body , suspensory ligament, and the iris are all part of this layer: called photoreceptors. There are two types of photoreceptors
Ciliary body– the thickening of choroid, fits between anterior (rods and cones) in the retina. (9)
margin of retina and posterior margin of iris.
Suspensory ligament– attached to the ciliary processes and
blends with the elastic capsule of the lens to hold it in.
Iris– colored part of the eye.
The retina is the incomplete innermost coat of the eyeball.
Three layers of neurons make up the sensory retina. Photoreceptor
neurons are the visual receptors, highly specialized for stimulation
by light rays. Bipolar neurons are the second layer and ganglion
neurons are the third layer. All axons of these neurons extend back
to the optic disc; part of the sclera, which contains perforations
through which the fibers emerge from the eyeball as the optic
nerve.
(5)
3. Locations of receptors (24)
VISION CONT.
Page 12 Page 3
Cavities & Humors
The eyeball has a large interior space divided into two cavities. The
anterior cavity lies in front of the lens and has two subdivisions:
Exteroceptors: are near the surface of the body. The extero-
The anterior chamber– the space anterior to the iris and posterior
ceptors located in the skin provide the sensations of pain,
to the cornea.
touch, temperature, and pressure.
The posterior chamber– the small space posterior to the iris and
Visceroceptors: located in the blood vessels and viscera.
anterior to the lens.
Proprioceptors: receptors located in muscles, tendons,
The posterior cavity is larger than the anterior cavity and it occupies
joints, and the external ear.
the entire space posterior to the lens, suspensory ligament, and ciliary
body.
Muscles
There are two types of eye muscles. The extrinsic eye muscle is the
skeletal muscles that attach to the outside of the eyeball and to the
bones of the orbit, and its named according to their position on the
eyeball. The muscles are superior, inferior, medial, and lateral rectus
muscles and the superior and inferior oblique muscles.
(5)
Accessory Structures
Eyebrows and eyelashes give some protection against foreign objects
entering the eye. Eyelids consist of voluntary muscle and skin with a
tarsal plate, lined with conjunctiva, a mucous membrane, and a pal-
pebral fissure where the upper and lower eyelids join together. Lacri-
mal glands are about the size and shape of an almond, and are locat-
ed at the upper, outer margin of each orbit. Approximately a dozen
small ducts lead from each gland and
drain tears onto the conjunctiva.
Lacrimal canals are small channels
that empty into lacrimal sacs.
Lacrimal sacs are located in a groove
in the lacrimal bone. Nasolacrimal
ducts are small tubes that extend
from the lacrimal sac into the inferior
meatus of the nose.
(5)
4. Take a gander at the Christmas
lights Process of seeing Taste cont. (23)
Page 4 Page 11
The cornea, pupil, iris, and lens work together to The Neural Pathway
refract light rays so that the rays from the Christmas
lights focus directly on the retina. The Taste Pathway
Light rays first touch the cornea. The cornea has Transduction occurs when different taste substances cause a
2 purposes: 1) it bends light rays as they pass through it change in the flow of ions across the membrane of a taste cell.
in order to focus them through the lens and towards the Different substances affect the membrane in different ways:
back of the eye. 2) its smooth, reflective surface serves Bitter and sweet substances bind into receptor sites which
to protect the eye from external damage. release other substances into the cell.
Once light passes the cornea, it hits the aqueous Sour substances contain H+ ions that block channels in the
humor, a clear watery fluid. The purpose of the aqueous membrane.
humor is to keep a constant pressure within the eye. Salty substances break up into Na+ ions which flow through
Behind the aqueous humor are the iris and the pupil. the membrane directly into the cell.
They both work together to control the amount of light Electrical signals generated in the taste cells are transmitted in 3
that enters the eye. The iris consists of two muscles on pathways:
either side of the pupil that can dilate or constrict to ad- The chorda tympani nerve conducts signals from the front and
just the size of the pupil. Behind the iris and the pupil is sides of the tongue.
the lens, and elastic structure that becomes thinner to The glosso-pharyngeal nerve conducts signals from the back of
focus on distant objects and thick to focus on nearby the tongue.
The vagus nerve conducts taste signals from the mouth and
objects.
the larynx.
All these parts of the eye work together to allow
These three nerves make connections in the brain stem in the nu-
you to see all the Christmas lights.
cleus of the solitary tract (NST) before going on to the thalamus
and then to two regions of the frontal lobe (the insula and the
(19)
frontal operculum cortex).
Why don’t deer see hunters who are
wearing bright orange?
Deer have under-developed cones. They have no
red-sensitive cones in their eyes, which prohibit
them from distinguishing red or orange from
green and brown.
5. All the tasty treats...yum! (23) PROCESS OF SEEING CONT.
Page 10 Page 5
Describe the role of Photopigments
Both rods and cones contain photopigments, or light sensitive pig-
ments compounds that are found in the distal area of both types of
photoreceptors near the pigments retina. A derivative called reti-
nal acts as the light-absorbing portion of all photopigments.
Rods– the single photopigment found in rods is rhodopsin.
Rhodopsin is highly light sensitive that a dim light can cause a
rapid breakdown of the photopigment into its opsin and retinal
components. Light causes retinal to change shape and the op-
sin molecule to expand or open.
Cones– 3 types of cones are present in the retina. Each con-
Taste buds- describe tains a photopigment different from the rhodopsin found in
rod cells. Each of the 3 primary colors (red, green, and blue)
Anatomy of taste reflect light rays of a different wavelength. Each wavelength
The tongue contains many ridges and valleys called papillae. There acts primarily on one type of cone, causing its particular pho-
are four types of papillae: topigment to break down and initiate impulse conduction by
1) Filiform papillae– cone shaped and found all over the tongue the cone. Brighter light is necessary for the breakdown of cone
(why gives the tongue its rough appearance). photopigments. (5)
2) Fungiform papillae– mushroom shaped and found at the tip
and sides of the tongue.
3) Foliate papillae– a series of folds along the sides of the tongue. Describe between nearsighted and farsighted.
4) Circumvallate papillae– shaped like flat mounds surrounded by How is it corrected?
a trench and found at the back of the tongue.
All papillae except filiform contain taste buds, so the very center of People with farsightedness (hyperopia) can see distant
your tongue (which only has filiform papillae) is “taste blind.” Each objects well, but have difficulty focusing on objects close up.
taste bud contains a number of taste cells which have tips that pro- People with nearsightedness (myopia) can focus well on objects
trude into the taste pore. close up, but have trouble seeing distant objects.
Glasses and contacts are the most common ways of cor-
recting either nearsightedness or farsightedness. Glasses help for
the abnormal shape of the eye so that
rays can hit the retina properly. Contact
lenses also work by refocusing light, and
may improve vision more than glasses
because the lenses sit directly on the
eyes.
7. The smells of Christmas time cont. The smells of Christmas time
Page 8 Page 7
(5)
Olfactory Pathways
When the level of odor-producing chemicals reaches a threshold
level, the following occurs: receptor potential, and then action po-
tential, is generated and passed to the olfactory nerves in the olfac-
tory bulb. The impulse then passes through the olfactory tract and
into the thalamic and olfactory centers of the brain for interpreta-
tion, integration, and memory storage.
Compare Olfaction in a human with a canine.
Genes between a dog and a human, suggest that our genes
evolved from a common mammalian ancestral repertoire by
successive duplications.
Olfactory Receptors
Olfactory receptors are unique because they are replaced on a regular
basis by germinative basal cells in the olfactory epithelium. They are
located in the most superior portion of the nasal cavity. They also con-
sist of epithelial support cells and specialized olfactory receptor neu-
rons.
Olfactory cilia– located on olfactory receptor neurons that touch
the olfactory epithelium linin the upper surface of the nasal cavity.
Olfactory cells– chemoreceptors; gas molecules or chemicals dis-
solved in the mucus over covering the nasal epithelium stimulate
the olfactory cells.
Olfactory epithelium– located in the most superior portion of the
nasal cavity.
Olfactory receptors– extremely sensitive and
easily fatigued
(5)