cells—basic unit of life tissues › connective › muscle › nervous › epithelial
Post on 26-Dec-2015
231 Views
Preview:
TRANSCRIPT
Control—Nervous and Endocrine Systems
Positive feedback: the body produces whatever is needed to keep it in balance (ex-childbirth)
Negative feedback: (most common) body senses an internal change and activates mechanisms that reverse, or negate, that change. (ex: sweating, blood pressure)
Why?? Stress is caused by an internal or
external stimulus that creates an imbalance and affects the body
The Nervous System Works with other organ
systems to respond to the environment
Made of specialized cells called neurons
Two parts:› CNS—central nervous system› PNS—peripheral nervous
system
The Neuron
What makes a nerve fire??
Impulse comes from either nerve or environment An impulse always travels in the same direction,
from axon to dendrite.
Central Nervous System
Parts Function
Brain
Cerebrum: conscious action, thinking,
intelligence, learning
Cerebellum: balance & movement
Brain stem: breathing, heart rate, swallowing
Process informationRelay messages
Analyze information100 billion neurons
Weighs 1.4 kgs
...all of your "thinking" is done by electricity
and chemicals
SpinalCord
Nerve Cord:Made up of bundles of nerves
Meninges:Membrane covering that bundles
nerves
Relays message to and from your brain.
Protective Structures Skull Meninges (3)- pia
mater, arachnoid layer, dura mater
Cerebrospinal fluid
The Peripheral Nervous System
Sensory Neurons- detects impulse and transmits to spinal cord, interneurons
Motor Neuron- sends impulse to body parts, causes movement.
Interneuron- connects sensory neuron and motor neuron
Peripheral Nervous System Everything outside of
the CNS
Somatic Nervous System:› Conscious control,
VOLUNTARY› Reflexes, walking, talking
Autonomic Nervous System:› INVOLUNTARY› Heart rate, breathing
1. Sensory neuron detects painful stimulus
2. Sensory neuron carries impulse to spinal cord.
3. An inter-neuron in spinal cord passes message to motor neuron.
4. A motor neuron carries impulse to muscle cell.
5. Muscle contracts.
Sensory Receptors
Sensitive to light and colors
Eyes
Sensitive to chemicals in the air and food
Nose and taste buds
Sensitive to touch, pressure, muscle stretching, sound, motions
Skin, skeletal muscles & inner ear
FunctionLocation
sType
Detect variations in temperature
Skin, body core and hypothalamus
Everywhere except the brain
Signal danger, injury or diseaseEx: itching
Iris:Colored part of the eye
Pupil: opening
Cornea: clear cover
Lens: focus objects
Muscle: move eye
Vitreous Humor: jellylike substance
Fovea: sharpest vision
Optic Nerve: impulses go to brain
Blood Vessels
Choroid: middle layer
Sclera: white part of eye
Retina: contains rods and cones
Ligaments: connects lens to muscles
SIGHT
Aqueous humor
Rods-detect light
Cones- detect color
Imagine the Hermann Grid as a map of city streets; most intersections appear to be grey, but when you look closely at any individual intersection, you will see that it is white. The streets, on the other hand, appear white no matter where you look.
Optical Illusions Hermann Grid
Optical Illusions Complemtary colors
Stare at the center of the flag for at least 20 second - even longer to enhance the effect - and then look at the white area such as a
light colored wall, or a white piece of paper.
The Ebbinghaus illusion is an optical illusion of relative size perception. In the best-known version of the illusion, two circles of identical size are placed near to each other and one is surrounded by large circles while the other is surrounded by small circles; the first central circle then appears smaller than the second central circle
One type of motion illusion is a type of optical illusion in which a static image appears to be moving due to the cognitive effects of interacting color contrasts and shape position. To properly view this effect, click the image above to see the full sized version.
Instructions: Close your left eye and fixate your right eye on the cross in the first diagram. If your eye is about 12 inches (30 cm) away from the monitor, you should notice that the round dot disappears. This distance may vary according to the screen resolution you have set.
You may be surprised to see that the dot is replaced, not by a black region, but rather blank white space. The brain simply "fills in" the most probable stimulus (in this case, a uniform white area) where there is none. The following examples demonstrate the "filling-in" phenomenon in greater detail. Apply the same instructions as given above and you should notice the red markings each time are replaced by the most probable pattern that your brain is able to perceive.
How many F’s are there?In the text opposite there are 10 F's! Most people underestimate the number of F's because they fail to notice them in the word 'of'. Function words like 'of' are unconsciously processed by our brain because they aren't important.
HearingCochlea: filled with hairs that vibrate
Semicircular canals: help with balance, equilibrium
Tympanic membrane: ear drum
StirrupHammer
Oval
windowAnvil
Auditory canal
Cochlear nerve
Estachian tubesRound window
Bone
Noises over 90 db can cause hearing loss over extended periods of time.
iPods with ear buds can produce levels of 110-120 db, like a rock concert.
It is recommended that you listen to volume no higher than 6 for no more that 1 hours a day.
Tinnitus (ringing in the ears)
Smell and Taste
Scent particles are chemicals detected by your nose
Scents are closely related to memories Taste buds are the receptors found in
your mouth
top related