Biology

Content Standard 6.1

Specialized cells enable organismsto monitor what is going on in the world around them.

Several body systemsadjust to maintainthese stable conditions.

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Homeostasis - 6 min

Movement of water through the cellmembrane.

Tonicity - 3 min


In an isotonic solution,water concentration isthe same inside andoutside the cell.

This is theideal conditionfor living cells.

In a hypotonic solution,water concentration isgreater outside the cellthan inside the cell.

Water willmove intothe cell.

In a hypertonic solution,water concentration isgreater inside the cellthan outside the cell.

Water willmove out of the cell.

The shrinking of a cell as water moves out by osmosis.

Normal plant cell

vacuoles contain water

Water beginningto move out of cell.

vacuoles begin to shrinkand cell membranebegins to pull away fromthe cell wall

Most of the waterhas moved outof the cell.

empty spacecell membrane

Nervous system - 5 min


TheCentral

Nervous System,

CNS

ThePeripheral Nervous System,

PNS

Central Nervous System,CNS

1 - cerebrum2 - brainstem3 - cerebellum4 - spinal cord

Brain

Peripheral Nervous System, PNS

Nerves that connect the CNSto the rest of the body.

B1 - Somatic Nervous System

Controls voluntary movementof the skeletal muscles.

B2 - Autonomic Nervous System

Controls involuntary actionsof the body.

There are more than10 Billion nerve cellsin the human body.

Nerve Cells

Nerve Cells - 5 min


The ThreeParts of aNeuron

Cell body structuresare the same asregular cells.

Carry signalstoward thecell body.

Carries signalsaway from thecell body.

Most neurons haveseveral dendrites...

but only one axon.

This gap is bridged by chemicals calledneurotransmitters.

1. Resting state -

the neuron is not conducting impulse.

2. Depolarization -

The neuron is stimulated. Sodium ions, Na+, move into the cell.

3. Repolarization -

Potassium ions, K+, move out of the cell to balance the charge.

4. Travel -

A wave of charge changesmoves across the cell.

5. Transmission -

Neurotransmitters are thechemical messengers thatbridge the synapse.

6. Refractory period -

The time it takes a neuron to return to its resting potential after being stimulated.

The refractory periodfor humans is4/1000 of a second.

120meters/sec

1/2

meter/sec

The Brain - 10 min

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Contains about 1 x 1011 neurons

Makes up about 2% of your body weight

Uses 20% of your body’s oxygen

The Cerebrum contains 75% of your neurons.

Reasoning, speech,movement, and emotions

Touch, pressure,temperature, and pain

Vision

Hearing and memory

Controls muscle coordinationand balance

Midbrain controlsreflexes and pupil size

Midbrain

Pons relays signals betweencerebrum & cerebellum

Pons

Medulla controls heart and breathing rate

Medulla

There are31 pairs of

Spinal Nerves

C 1-7

T 1-12

L 1-5

S 1-5

There are 12 pairs of Cranial Nerves

Sensory Nervesof the PNS

cover all partsof the body.

Concentration of sense organs at the “front” of an organism.

What is the advantage of cephalization?

Traumatic Brain Injuries

Degenerative Brain Diseases

Concussion

occurs when small braincapillaries are broken,a brain bruise.

Contusion

the result of marked tissue damage.

Cerebral Edema

swelling of the brain due to injury.

CerebrovascularAccidents - CVAs

commonly called strokes, occur when blood circulation to an area of the brain is blocked.


Stroke - 6 min

Temporary brain ischemia,restriction of blood flow, is called a transient ischemic attack, TIA.

Alzeimer’s disease

a progressive degenerativedisease of the brain thateventually results in dementia,mental deterioration.

Any one spot onthe skin cannot"feel" every sensation.

There are even spots on the skin that have NO sensory receptors.

Touch - 3 min


How many differenttastes are there?

Taste - 1 min


How many differenttastes are there?

There are FIVE tastes.

Salty - Na+

Sour - H+

Sweet - organic molecules

Bitter - Quinine

Umami - glutamate (MSG)

Umami is Japanese for "wonderful taste",

it is the opposite of bitter.

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"savory"

Of the approximately 10,000 taste buds, MOST are locatedon the tongue.

However, a few are found on the soft palate and the innersurface of the cheeks.

Current researchshows that tastebuds of all kinds arescattered acrossthe tongue surface.

Bitter (base) - 0.000008 M

Sour (acid) - 0.0009 MSalt & Sugar - 0.01 M

Threshold Taste Concentrations

Bitter (base) - 0.000008 M

Sour (acid) - 0.0009 MSalt & Sugar - 0.01 M

Why do we havesuch good receptorsfor bitter??



Most poisonshave a

bitter taste.

Smell - 1 min


1000s of olfactoryreceptors occupya postage stampsized area in theroof of eachnasal cavity.

Hundreds ofdifferent odorantsare interpretedas the “fingerprint”for a particular odor.

Most of what we call "flavor"actually comes from the odorsthat reach the nasal passagesat the back of the throat.

Why are some "perfumes" cheap, while others arevery expensive?

It all depends on"staying power"

3-methyl-1-butanethiol



3-MBT



A. CarotidB. RadialC. BrachialD. AorticE. AbdominalF. FemoralG. Popliteal

7 Arterial Pulse Points

Sound occurswhen a movingor vibratingobject causesthe air aroundit to move.

Bones of the middle ear

Malleus(hammer)

Incus(anvil)

Stapes(stirrup)

The smallest bones in the body

Hearing - 6 min




A Penrose triangleis an impossible object.



There are NO curved lines on this drawing.

Count The Black Dots



Squares A and B are BOTH this shade of grey.

The green and blue on this drawingare the SAMEcolor.



Which way is the wheel turning?

You can see nearly 8 milliondifferent colors

Blinking causes your eyes to beclosed about30 minutesevery day.

Properties of vision - 4 min


Close your left and eye and focus your right eye on the tiny cross. At some point the big circle will disappear as it crosses your 'blind spot'.

Rods and Cones are the receptor cells for vision

Rods function in low lightand do not detect color.

Rods detect motion butdo not provide sharp detail.

Cones function in bright light and detect color.

Cones provide sharp detail butare not as responsive to motion.

How can scientists saywith confidence that most mammals arecolorblind?



It's all about the CONES.

Full color vision requires

three

types ofcone cells.





S cones respond to short wavelengths of light.

M cones respond to medium wavelengths of light.

L cones respond to long wavelengths of light.



Humans have about 5 millioncone cells and about90 million rod cellsin each eye.



Humans, apes, most old world monkeys, ground squirrels, and many species of fish, birds, and insects have well-developed color vision,(3 cone types).



Mammals with limited color vision include mice, rats, rabbits, cats, and dogs.

These mammalshave only TWOtypes of cones.

Trichromatic

Vision

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DichromaticVision

WhatWeSee

WhatDogSees



Monochromatic Vision

WhatBullSees

Tetrachromatic, or even

Pentachromatic Vision



Whatdoes that

mean?



Nocturnal animals - such as foxes,skunks, and raccoons - whose vision is specialized for dim light seldom have good color vision.

Owls seem to be an exception.

Bees have trichromatic vision,

which is insensitive to red

but sensitive in ultraviolet to

a color called

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Plants - 13 min


Early plant scientists observed these movements, but could not explain the

mechanism causing them.

Today, we know these growth responses are

caused by hormones.

Stimulates cell elongation

Stimulates shoot elongation

Tropisms are caused by growth hormones.

Phototropisma growth response to light

Solar tracking is a hydroscopic movement of leaves or flowers as they follow the sun's movement across the sky.

Thigmotropism allows vines to climb.

Thigmotropisma growth response to

contact with a solid object

Roots are positively gravitropic, growing downward.

Gravitropisma growth response to gravity

Stems are negatively gravitropic, growing upward.

Gravitropisma growth response to gravity

Chemotropisma response to chemicals

Most plants have a positive response to water - growing toward it.

Hydrotropisma response to water

are NOT tropisms.

They are fast movements due to changes inwater pressure

Hydroscopic Movements

Biology

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