Tuesday, April 21, 2009

Nervous System

Hi ladies! Sorry for posting this so late. Don't forget that ch 50 is due tomorrow, the ch 46-48 take home is due tomorrow, and we have a ch 48/49 vocab quiz. IT'S ALSO LATE START! :)

Today in C block Lindsey showed us the awesome design for the AP Bio t-shirt. They are really cute and everyone should get one! She's going to post the link on the blog so that B block can see the shirts, too. We also took a vocab quiz and took more notes on the nervous system.

Chapter 50 Vocab:
Cardiac muscle
a type of muscle that forms the contractile wall of the heart. Its cells are joined by intercalated disks that relay each heartbeat

sarcoplasmic reticulum
a specialized endoplasmic reticulum that regulates the calcium concentration in the cytosol

Z lines
The borders of a sacromere

the regulatory protein that blocks the myosin-binding sites on the actin molecules

A band
the broad region that corresponds to the length of the thick filaments of myofibrils

I band
The area near the edge of the sacromere where there are only thin filaments

the fundamental, repeating unit of striated muscle, deliminated
By the Z lines

Cone cell
one of two types of photoreceptors in the vertebrate eye; detects color during the day

thick filament
a filament composed of staggered arrays of myosin molecules; a component of myofibrils in muscle fibers

Hydrostatic skeleton
a skeletal system composed of fluid held under pressure in a closed body compartment; the main skeleton of most cnidarians, flatworms, nematods, and annelids

rod cell
one of two kinds of photoreceptors in the vertebrate retina; sensitive to black and white and enables night vision

thin filament
the smaller of the two myofilaments consisting of two strands of actin and two strands of regulatory protein coiled around one another

the thick and thin filaments that form the myofibrils

Hair cell
a type of mechanoreceptor that detects sound waves and other forms of movement in air or water

a visual pigment consisting of retinal and opsin. When rhodopsin absorbs light, the retinal changes shape and dissociates from the opsin, after which it is converted back to its original form

the strengthening of stimulus energy that is otherwise too weak to be carried into the nervous system
pic n/a

A class of naked dendrites in the epidermis of the skin

a sensory receptor that detects stimuli within the body, such as blood pressure and body position

tympan-a drum
sacc-a sack
omma-the eye
mechano-an instrument
coch- a snail
utric- a leather bag
fovea- a pit
Graph from class:

This is an action potential graph. An action potential or impulse can only be generated in the axon of a neuron. When the neruon is stimulated the sodium channels open and sodium ions flood into the cell. As a response, potassium channels open allowing potassium ions to leave the cell. This rapid movement (the upward line in the graph) is called depolarization. As you can tell, this lasts a very short amount of time. The potassium pump respores the membrane to its original polarized condition by pumping sodium and potassium ions back to their original location. This period is called repolarization. When the potential drops back down it goes through short period of time called the refractory period during which the neuron can't respond to another stimulus. Once the potential levels out, the neuron has reached it's resting state.
Questions from Ch 46-48 Take Home
1) Genetic mutations in asexually reproducing organisms lead to more evolutionary change than do genetic mutations in sexually reproducing ones because
A) asexually reproducing organisms, but not sexually reproducing organisms, pass mutations to their offspring
B) More genetic variation is present in organisms that reproduce asexually than is present in those that reproduce sexually
C) sexually reproducing organisms can produce more offspring in a given time than can sexually reproducing organisms
D) asexually reproducing organisms devote more time and energy to the process of reproduction than do sexually reproducing organisms
E) asexually reproducing organisms have more dominant genes than organisms that reproduce sexually
2) The Small portion of the embryo that will become its dorsal side develops from
A) morula
B) primitive streak
C) gray crescent
D) blastocoel
E) archenteron
3) Action potentials move along axons
A) by reversing the concentration gradients for sodium and potassium ions
B) more rapidly in myelinated than in non-myelinated axons
C) by the direct action of acetylcholine on the axonal membrane
D) by activating the sodium-potassium "pump" at each point along the axonal membrane
E) more slowly in axons of large than in small diameter
Answers: 1) A 2) C 3)A

Related FRQ


FRQ grading key

No comments: