.
A broadly acceptable definition of a
sense would be "a system that consists of
a sensory cell type that responds to a
sp...
Somatic sensation consists of the various sensory receptors that
trigger the experiences labeled as touch or pressure(henc...
Humans can generally hear sounds with frequencies between 20 Hz and 20
kHz. Human hearing is able to discriminate small di...
primAry Auditory cortex
Neurons in the auditory cortex are organized according to the
frequency of sound to which they res...
The visible part is called the pinna and functions to
collect and focus sound waves. Some humans can
move the pinna (with ...
middle eAr
The middle ear contains three ossicles, which
amplify vibration of the eardrum into pressure
waves in the fluid...
inner eAr
The inner ear is the
bony labyrinth, a
system of passages
comprising two
main functional
parts:
(1)the organ of
...
The semicircular canals are three
half-circular, interconnected tubes
located inside each ear. Because the
angles between ...
FunctionFunction
In brief: theIn brief: the cochleacochlea is filledis filled
with awith a watery liquidwatery liquid, whi...
Language Acquisition
The "critical period" is a time
in the early stages of a
human’s life during which
critical language ...
Optical
illusiOns
and VisiOn
http://www.michaelbach.de/ot/
The visual cortex is the most massive system in
the human brain and is responsible for higher-
level processing of the vis...
The visual system interprets the
information from visible light
to build a representation of the
world surrounding the bod...
The information about the image via the eye is transmitted to the brain along
the optic nerve. In humans, the optic nerve ...
Hyperopia
Hyperopia,
colloquially as
farsightedness, is a
defect of vision in
which light produces
an image focus
behind t...
View your own retinal blood vessels!
Try it yourself –Blind Spot
A O X
Instructions: Your face should be very
close to the...
The olfactory system is the sensory system used for smell. The
accessory olfactory system senses pheromones. The olfactory...
Patrick J. Lynch, medical illustrator
Odorants are inhaled and then transduced into electrical signals which then travel
a...
Olfaction and taste
Olfaction, taste, and trigeminal receptors together contribute
to flavor. The human tongue can only di...
The gustatory system is the sensory system that
uses taste buds (or lingual papillae) on the upper
surface of the tongue t...
In humans, the sense of
taste is conveyed via
three of the twelve
cranial nerves. The
facial nerve (VII) carries
taste sen...
Each of the five senses
activates a separate area of
the cerebral cortex, the sheet
of neurons that makes up the
outer lay...
Verses about our special sensesVerses about our special senses!
Your eyes have seen all that
the LORD did in Egypt to
Phar...
Does he who implanted the ear not
hear? Does he who formed the
eye not see?
Psalm 94:8-10
My ears had heard of you but now...
Species
Lived when (
mya)
Lived where Adult height Adult mass
Brain volume
(cm³)
Fossil record
Discovery /
publication of
...
Somatic.specialsenses
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Somatic.specialsenses

  1. 1. . A broadly acceptable definition of a sense would be "a system that consists of a sensory cell type that responds to a specific kind of physical energy, and that corresponds to a defined region within the brain where the signals are received and interpreted." School children are routinely taught that there are five senses (sight, hearing, smell, taste, touch). The special senses are the first four of these, touch is specifically excluded as a special sense. Instead, the various aspects of touch (pain, heat, pressure) are all categorized as somatic senses.
  2. 2. Somatic sensation consists of the various sensory receptors that trigger the experiences labeled as touch or pressure(hence shape, softness, texture, vibration, etc.), temperature (warm or cold), pain (including itch and tickle), and the sensations of muscle movement and joint position (including posture, movement, and facial expression). Touch may simply be considered one of five human senses; however, when a person touches something or somebody this gives rise to various feelings or emotions. http://www.phy.syr.edu/courses/modules/MM/brain/large/large.html# During special tests, scientists observe that different areas of the brain become active when subject to different stimuli. The above image is a visual representation only, not actual brain test imagery. The areas of the brain that ‘light up’ when feeling pain and empathy are shown in red and blue respectively. Pain and Empathy
  3. 3. Humans can generally hear sounds with frequencies between 20 Hz and 20 kHz. Human hearing is able to discriminate small differences in loudness (intensity) and pitch (frequency) over that large range of audible sound. The ear is sensitive to a change in pressure equal to 1X10-10 atmospheres . "Computation Provides a Virtual Recording of Auditory Signaling", Public Library of Science Biology, January 2005, Volume 3, Issue 1, e26, graphic ref. DOI: 10.1371/journal.pbio.0030026.g001 Sound is a disturbance of mechanical energy that travels through matter as a longitudinal wave. Sound is characterized by the properties of sound waves, which are frequency, wavelength, period, amplitude, and speed. Auditory
  4. 4. primAry Auditory cortex Neurons in the auditory cortex are organized according to the frequency of sound to which they respond best. Neurons at one end of the auditory cortex respond best to low frequencies; neurons at the other respond best to high frequencies. The auditory cortex is the most highly organized processing unit of sound in the brain. This cortex area controls hearing, language and music.
  5. 5. The visible part is called the pinna and functions to collect and focus sound waves. Some humans can move the pinna (with the auriculares muscles). outer eAr (pinnA, or Auricle) From the pinna the sound pressure waves move into the ear canal, a simple tube running to the middle ear. This tube amplifies frequencies in the range 3 kHz to 12 kHz.
  6. 6. middle eAr The middle ear contains three ossicles, which amplify vibration of the eardrum into pressure waves in the fluid in the inner ear. The eustachian tube joins the tympanic cavity with the nasal cavity, allowing pressure to equalize between the inner ear and throat. Ordinarily, when sound waves in air strike liquid, more than 99% of the energy is reflected off the surface of the liquid. The middle ear allows the impedance matching of sound traveling in air and sound traveling in liquid, overcoming the interface between them. eustAchiAn tube The movement of the ossicles may be stiffened by two muscles, the stapedius and tensor tympani, which are under the control of the facial nerve and trigeminal nerve, respectively. These muscles contract in response to loud sounds, thereby reducing the transmission of sound to the inner ear. incus malleus stapes
  7. 7. inner eAr The inner ear is the bony labyrinth, a system of passages comprising two main functional parts: (1)the organ of hearing, or cochlea and the (2) vestibular apparatus, the organ of balance that consists of three semicircular canals and the vestibule. The vestibule is the region of the inner ear where the semicircular canals converge, close to the cochlea (the hearing organ). The vestibular system works with the visual system to keep objects in focus when the head is moving. The brain receives, interprets, and processes the information from these systems that control our balance.
  8. 8. The semicircular canals are three half-circular, interconnected tubes located inside each ear. Because the angles between the canals are not perpendicular, movements of the head stimulate horizontal and vertical canals simultaneously.
  9. 9. FunctionFunction In brief: theIn brief: the cochleacochlea is filledis filled with awith a watery liquidwatery liquid, which, which moves in response to themoves in response to the vibrationsvibrations coming from thecoming from the middle ear. As the fluidmiddle ear. As the fluid moves, thousands ofmoves, thousands of "hair"hair cellscells" are set in motion, and" are set in motion, and convert that motion toconvert that motion to electrical signalselectrical signals that arethat are communicated viacommunicated via neurotransmitters to manyneurotransmitters to many thousands of nerve cells.thousands of nerve cells.
  10. 10. Language Acquisition The "critical period" is a time in the early stages of a human’s life during which critical language skills are developed. If the organism does not receive the appropriate stimulus during this "critical period", it may be difficult, or even impossible, to develop some functions later in life. Broca's area is the section of the human brain (in the frontal lobe of the cortex) that is involved in language processing, speech production. Wernicke's area is on the auditory cortex (part of the brain where the temporal lobe and parietal lobe meet). Wernicke’s area is where the specialized language skill areas can be found for the majority of people and is particularly known to be involved in the understanding and comprehension of spoken language. . http://www.brainconnection.com/teasers/?main=illusion/back-speech
  11. 11. Optical illusiOns and VisiOn http://www.michaelbach.de/ot/
  12. 12. The visual cortex is the most massive system in the human brain and is responsible for higher- level processing of the visual image. It lies at the rear of the brain (highlighted in the image), above the cerebellum. “To suppose that the eye, (with so many parts all working together)… could have been formed by natural selection, seems, I freely confess, VisiOn
  13. 13. The visual system interprets the information from visible light to build a representation of the world surrounding the body. Retina The retina consists of a large number of photoreceptor cells which contain a particular protein molecule called an opsin. In humans, there are two types of opsins, rod opsins and cone opsins. Either opsin absorbs a photon (a particle of light) and transmits a signal to the cell through a signal transduction pathway. In the retina about 130 million photoreceptors absorb light and roughly 1.2 million axons transmit information from the retina to the brain.
  14. 14. The information about the image via the eye is transmitted to the brain along the optic nerve. In humans, the optic nerve is connected directly to the brain. Rods and cones differ in function. Rods are found primarily in the periphery of the retina and are used to see at low levels of light. Cones are found primarily in the center (or fovea) of the retina. There are three types of cones that differ in the wavelengths of light they absorb; they are usually called short or blue, middle or green, and long or red. Cones are used primarily to distinguish color and other features of the visual world at normal levels of light.
  15. 15. Hyperopia Hyperopia, colloquially as farsightedness, is a defect of vision in which light produces an image focus behind the retina. Myopia, or nearsightedness, is a refractive defect of the eye in which light produces an image focus in front of the retina. Myopia Normal vision Macular degener- ation
  16. 16. View your own retinal blood vessels! Try it yourself –Blind Spot A O X Instructions: Your face should be very close to the screen. Cover right eye and focus the left eye on the X. Now slowly move away from the screen. The O will disappear, while the A which is further to the left is still visible. (Observe that you do not see a hole. Instead of the O you see a uniform grey background. The "hole" is filled in by your brain. Make sure there is not a glare on the screen as it will obscure the whole vision.)
  17. 17. The olfactory system is the sensory system used for smell. The accessory olfactory system senses pheromones. The olfactory system is often spoken of along with the gustatory system as the chemosensory senses because both transduce chemical signals into perception. Function The olfactory system must accomplish several tasks: *Create a representation of the odor *Determine the concentration of the odor *Distinguish a new odor from the background environmental odors *Pair the odor with a memory of what the odor represents
  18. 18. Patrick J. Lynch, medical illustrator Odorants are inhaled and then transduced into electrical signals which then travel along the olfactory nerve into the olfactory bulb. Axons from the olfactory sensory neurons converge in the olfactory bulb to form tangles called glomeruli. Inside the glomulerus, the axons contact the dendrites of mitral cells. Mitral cells send their axons to a number of brain areas, including the amygdala.
  19. 19. Olfaction and taste Olfaction, taste, and trigeminal receptors together contribute to flavor. The human tongue can only distinguish among seven to eight distinct types of taste, while the nose can distinguish among hundreds of substances, even in minute quantities. Olfaction amplifies the sense of taste. Odor information is easily stored in long term memory and has strong connections to emotional memory. This is possibly due to the olfactory system's close anatomical ties to the hippocampus and amygdala, areas of the brain that have long been known to be involved in emotion.
  20. 20. The gustatory system is the sensory system that uses taste buds (or lingual papillae) on the upper surface of the tongue to provide information about the taste of food being eaten. There are at least four types of taste "bud" (receptor) on the tongue. The inabilty to taste is called ageusia. It is known that there are four taste sensations: Sweet, Bitter, Salty, and Sour.
  21. 21. In humans, the sense of taste is conveyed via three of the twelve cranial nerves. The facial nerve (VII) carries taste sensations from the anterior two thirds of the tongue, the glossopharyngeal nerve (IX) carries taste sensations from the posterior one third of the tongue while a branch of the vagus nerve (X) carries some taste sensations from the back of the oral cavity. The human tongue has about 10,000 taste buds. Taste is a form of chemoreception which occurs in specialized receptors in the mouth. serotonin is thought to act as an intermediary hormone which communicates with taste cells within a taste bud, mediating the signals being sent to the brain.
  22. 22. Each of the five senses activates a separate area of the cerebral cortex, the sheet of neurons that makes up the outer layer of the brain's hemispheres. http://www.hhmi.org/senses/a150.html Scott T. Barrows- National Geographic Society Summary (another example of WPP)
  23. 23. Verses about our special sensesVerses about our special senses! Your eyes have seen all that the LORD did in Egypt to Pharaoh, to all his officials and to all his land. 3 With your own eyes you saw those great trials, those miraculous signs and great wonders. 4 But to this day the LORD has not given you a mind that understands or eyes that see or ears that hear. Deuteronomy 29:2-4 "Now, my God, may your eyes be open and your ears attentive to the prayers offered in this place……… …. 14 if my people, who are called by my name, will humble themselves and pray and seek my face and turn from their wicked ways, then will I hear from heaven and will forgive their sin and will heal their land. 15 Now my eyes will be open and my ears attentive to the prayers offered in this place. 16 I have chosen and consecrated this temple so that my Name may be there forever. My eyes and my heart will always be there. 2 Chronicles 6- 7:16 For the eyes of the LORD range throughout the earth to strengthen those whose hearts are fully committed to him. 2 Chronicles 16:8-10 Ears that hear and eyes that see— the LORD has made them both. Proverbs 20:11-13
  24. 24. Does he who implanted the ear not hear? Does he who formed the eye not see? Psalm 94:8-10 My ears had heard of you but now my eyes have seen you. Job 42:4-6 However, as it is written: "No eye has seen, no ear has heard, no mind has conceived what God has prepared for those who love him" — 1 Corinthians 2:8-10 Since ancient times no one has heard, no ear has perceived, no eye has seen any God besides you, who acts on behalf of those who wait for him. Isaiah 64:3-5 Look, he is coming with the clouds, and every eye will see him, even those who pierced him; and all the peoples of the earth will mourn because of him. So shall it be! Amen. Revelation 1:6-8 How, then, can they call on the one they have not believed in? And how can they believe in the one of whom they have not heard? And how can they hear without someone preaching to them? 15 And how can they preach unless they are sent? As it is written, "How beautiful are the feet of those who bring good news!“
  25. 25. Species Lived when ( mya) Lived where Adult height Adult mass Brain volume (cm³) Fossil record Discovery / publication of name H. habilis 2.2 – 1.6 Africa 1.0–1.5 m (3.3–4.9 ft) 33–55 kg (73– 120 lb) 660 many 1960/1964 H. erectus 2 – 0.03 Africa, Eurasia (Java, China, Caucasus) 1.8 m (5.9 ft) 60 kg (130 lb) 850 (early) – 1100 (late) many 1891/1892 H. rudolfensis 1.9 Kenya 1 skull 1972/1986 H. georgicus 1.8 Republic of Georgia 600 few 1999/2002 H. ergaster 1.9 – 1.4 E. and S. Africa 1.9 m (6.2 ft) 700–850 many 1975 H. antecessor 1.2 – 0.8 Spain 1.75 m (5.7 ft) 90 kg (200 lb) 1000 2 sites 1997 H. cepranensis 0.9 – 0.8? Italy 1000 1 skull cap 1994/2003 H. heidelberge nsis 0.6 – 0.25 Europe, Africa, China 1.8 m (5.9 ft) 60 kg (130 lb) 1100–1400 many 1908 H. neanderthal ensis 0.35 – 0.03 Europe, W. Asia 1.6 m (5.2 ft) 55–70 kg (120– 150 lb) (heavily built) 1200–1700 many (1829)/1864 H. rhodesiensis 0.3 – 0.12 Zambia 1300 very few 1921 H. sapiens sapi ens 0.2 – present worldwide 1.4–1.9 m (4.6–6.2 ft) 50–100 kg (110–220 lb) 1000–1850 still living —/1758 H. sapiens idalt u 0.16 – 0.15 Ethiopia 1450 3 craniums 1997/2003 H. floresiensis 0.10 – 0.012 Indonesia 1.0 m (3.3 ft) 25 kg (55 lb) 400 7 individuals 2003/2004

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