The Eukaryotic Cell; The Nervous System

Question 1

___ can exit the nucleus through ___ ___

Answer 1

RNA can exit the nucleus through the nuclear pores, but DNA cannot

Question 2

nucleolus

Answer 2

within the nucleus, where rRNA is transcribed an the subunits of the ribosome are assembled os

Question 3

cisternal space

Answer 3

ER lumen, extracellular fluid side of ER?

Question 4

granular/rough ER

Answer 4

near the nucleus, many ribosomes attached on cytosolic side

translation propels proteins into the ER lumen as they are created

Question 5

Golgi apparatus/complex

Answer 5

newly synthesized proteins from ER lumen
series of flattened membrane bound sacs
organizes and concentrates the proteins

Question 6

lysosomes

Answer 6

contain acid hydrolases/hydrolytic enzymes, enzymes capable of breaking down every major type of macromolecule within cell
come from the Golgi

Question 7

agranular/smooth ER

Answer 7

tubular, glucose from glycogen
production of triglycerides and phospholipids
lipid synthesis, including steroids
oxidizes foreign substances (drugs, toxins, etc.)

Question 8

adipocytes

Answer 8

cells containing predominantly fat droplets

Question 9

peroxisomes

Answer 9

production and breakdown of hydrogen peroxide

Question 10

cytoskeleton

Answer 10

network of filaments, determine structure and motility of cell
microtubules and microfilaments

Question 11

microtubules

Answer 11

larger than microfilaments
rigid hollow tubes made from a protein called tubulin
makes up mitotic spindle, flagella, and cilia
have + and - end

Question 12

axoneme

Answer 12

major portion of flagellum and cilium, contains 9 pairs of microtubules forming a circle around 2 long microtubules in a 9+2 arrangement

Question 13

dynein

Answer 13

protein that forms cross bridges to connect each of the outer pairs of microtubules to their neighbor in the 9+2 arrangment of axonemes in flagellum and cilium
cross bridges create whip action of cilia and wiggle of flagella

Question 14

centrosome

Answer 14

major microtubule organizing center in the cell

Question 15

in humans, cilia are found only in the ____

Answer 15

fallopian tubes and respiratory tract

Question 16

actin

Answer 16

forms microfilametns

Question 17

microfilament function

Answer 17

produce contracting force in muscle, active in cytoplasmic streaming, phagocytosis, microvilli movement, cytokinesis

Question 18

eukaryotic vs. prokaryotic flagella

Answer 18

eukaryotic: 9+2 microtubule arrangement, whip like action
prokaryotic: thin strand of single protein flagellin, rotate

Question 19

Krebs cycle takes place ____

Answer 19

inside the mitochondria

Question 20

cristae

Answer 20

infoldings of mitochondrial inner membrane

Question 21

neuronal communication vs. hormonal communication

Answer 21

neuronal: rapid, direct, specific
hormonal: slower, spread throughout the body, affect many cells and tissues in many different ways

Question 22

dendrites

Answer 22

receive a signal to be transmitted

Question 23

axon hillock

Answer 23

where cell body joins with axon

generates axon potential in all directions and down axon if stimulus is great enough from cell body

Question 24

axon

Answer 24

carries action potential to synapse

Question 25

resting potential

Answer 25

established by equilibrium between passive diffusion of ions across the membrane and the Na/K pump

Question 26

Na/K pump pumps....

Answer 26

3 Na out, 2 K in

Question 27

depolarization

Answer 27

voltage gated sodium channels, Na flows into cell via positive feedback, --> positive inside cell, negative outside

Question 28

repolarization

Answer 28

Voltage gated potassium channels open, K flows out of cell, makes inside more negative

Question 29

hyperpolarization

Answer 29

inside membrane becomes even more negative than resting potential, before potassium gates close

Question 30

any stimulus greater than the ___ ____ creates the same size action potential

Answer 30

threshold stimulus, action potential is all-or-nothing

Question 31

synapse

Answer 31

how nerve impulses are transmitted from one cell to another | chemically or electrically (uncommon)

Question 32

electrical synapses

Answer 32

gap junctions between cells cardiac muscle, visceral smooth muscle, few neurons much faster

Question 33

chemical synapses

Answer 33

unidirectional | Ca2+ into cell --> neurotransmitters across synaptic cleft,

Question 34

Brownian motion

Answer 34

random motion of molecule, neurotransmitter diffusion across synaptic cleft

Question 35

slowest step in transfer of nervous signal

Answer 35

chemical synapse

Question 36

second messenger system

Answer 36

active another molecule inside the cell to make changes, ex: G protein often activate second messenger for prolonged changes, ex: memory

Question 37

myelin

Answer 37

electrically insulating sheath, increases rate that axon can transmit signlas myelinated axon appear white

Question 38

Schwann cells

Answer 38

produce myelin in peripheral nervous system

Question 39

white matter vs. gray matter

Answer 39

``` white = myelinated axons gray = cell body ```

Question 40

nodes of Ranvier

Answer 40

tiny gaps between myelin | actions potential jumps from one node to the next

Question 41

saltatory conduction

Answer 41

action potential jumping from node to node

Question 42

sensory/afferent neurons

Answer 42

``` receive signals from a receptor cell that interacts with its environment, transfers signal to other neurons located dorsally (toward back) from the spinal cord ```

Question 43

interneurons

Answer 43

transfer signals from neuron to neuron, 90% neurons in the brain

Question 44

motor/efferent neurons

Answer 44

``` carry signals to a muscle or gland called the effector located ventrally (towards the front or abdomen) ```

Question 45

nerves

Answer 45

axons and dendrites bundled together

Question 46

Central nervous system

Answer 46

brain and spinal cord | integrate nervous signals between sensory and motor neurons

Question 47

somatic nervous system

Answer 47

respond to external environment,, sensory and motor, only skeletal muscle, consciously controlled, voluntary

Question 48

autonomic nervous system

Answer 48

signals form viscera, motor portion conducts signals to smooth muscle, cardiac muscle, glands involuntary

Question 49

motor portion of autonomic nervous system divided into.....

Answer 49

sympathetic - fight or flight | parasympathetic- rest and digest

Question 50

acetylcholine

Answer 50

neurotransmitter used by all preganglionic neurons in the autonomic nervous system and by postganglionic neurons in parasympathetic nervous system **somatic and parasympathetic

Question 51

postganglionic neurons of sympathetic nervous system use ____

Answer 51

epinephrine or norepinephrine / adrenaline or noradrenaline | **sympathetic system only

Question 52

autonomic pathways are controlled mainly by the ___

Answer 52

hypothalamus

Question 53

cerebrum/cerebral cortex

Answer 53

higher brain, cortical brain | higher level thoughts and consciousness, store memories, process thoughts

Question 54

light reflects off an object in the external environment and first strikes the eye on the ___

Answer 54

cornea - nonvascular, made of collagen, most bending of light

Question 55

ciliary muscle

Answer 55

circles the lens, focus light onto retina

Question 56

image in retina is ...

Answer 56

real and inverted

Question 57

retina

Answer 57

covers inside of back of eye | contains rods and cones

Question 58

rods cannot distinguish...

Answer 58

cannot distinguish color, cones can

Question 59

iris

Answer 59

color part of eye, made from circular and radial muscles that constrict/dilate pupil

Question 60

pupil

Answer 60

opening in iris

Question 61

tympanic membrane

Answer 61

ear drum, begins middle ear

Question 62

3 bones of inner ear

Answer 62

malleus, incus, stapes

Question 63

cochlea

Answer 63

detects sound (by hair cells of organ of Corti)

Question 64

semicircular canals

Answer 64

balance, detect orientation and movement of the head