Mcat Bio Chapter 4

Front 1

What does a tight junction do? Where would you find it?

Back 1

forms a watertight seal from cell to cell; epithelial tissue in organs like the bladder, intestines, kidney

Front 2

What does a desmosome do? Where would you find it?

Back 2

joins to cells at a single point, attaching directly to the cytoskeleton of each cell; found in tissues that experience a lot of stress, i.e. skin, or intestinal epithelium

Front 3

What are Gap junctions? What do they do?

Back 3

are small tunnels connecting cells, allowing small molecules and ions to move between cells; heart

Front 4

communication isaccomplished chemically via three types of molecules: NAME

Back 4

1. Neurotransmitters-travel over very short intercellular gaps
2. local mediators-function in the immediate area around the cell where they were released
3. hormones-travel throughout the organism via the blood stream

Front 5

Where does a neuron use for its chemical energy?

Back 5

glucose

Front 6

Partsof a neuron: name and describe (pg. 84)

Back 6

dendrites by the nucleus recieve signal, axon covered in myelin sheath carry signal away, and axon terminal sends signal to synapse

Front 7

Study action potential Na/ K pump on pg. 86 and in zoo notes

Back 7

study

Front 8

Does a neurotransmitter stay connected for a long time?

Back 8

no, or else the postsynaptic cell is overstimulated

Front 9

Acetycholine, a common neurotransmitter, has an ____ effect on the heart, but an _____ effect on the visceral smooth muscle of the intestines

Back 9

inhibitory, excitatory

Front 10

When would a second messenger system be favored?

Back 10

during prolonged change, i.e. memory

Front 11

What is saltatory conduction?

Back 11

the "jumping distrubance" of a signal from one node of Ranvier to another

Front 12

Types of neurons: sensory (afferent). Describe its function.

Back 12

receive signals from a receptor cell that interacts with its enviroment. The neuron then transfers this signal to other neurons. 99% of sensory input is disguarded by the brain

Front 13

Types of neurons: interneurons. Describe its function.

Back 13

transfer signals from neuron to neuron. 90% of neurons in the human body are interneurons

Front 14

Types of neurons: Motor (efferent) neurons. Describe its function.

Back 14

carry signals to a muscle or gland called the effector.

Front 15

Sensory neurons are dorsal or ventral to the spine?

Back 15

dorsal

Front 16

Motor neurons are dorsal or ventral to the spine?

Back 16

ventral

Front 17

The nervous system has two major divisions: the _____ and the ____

Back 17

CNS and PNS

Front 18

The CNS includes what?

Back 18

brain and spine

Front 19

The PNS can be divided into the _____ nervous system and _____ nervous system

Back 19

somatic and autonomic

Front 20

The somatic nervous system is designed primarily to respond to the _____ enviroment

Back 20

external

Front 21

The cell bodies of somatic motor neurons are located where?

Back 21

in the ventral horns of the spinal cord

Front 22

The autonomic nervous sytem is further divided into the _____ and ______

Back 22

sympathetic and parasympathetic systems

Front 23

What does the sympathetic system do?

Back 23

"fight or flight"-stops digestion, increases heart rate, dilates pupils

Front 24

What does the parasympatheic nervous sytem do?

Back 24

Allows body to reestablish homeostasis-continue digestion, shrinks pupils, promotes excretory

Front 25

The body contain 5 types of sensory reeptors, what are they?

Back 25

-mechanoreceptors (touch)
-thermoreceptors (temperature change)
-nociereceptors (pain)
-electromagnetic receptors (light)
-chemoreceptors (taste, smell, and blood chemistry)

Front 26

In the eye, when the ciliary muscle is activated, what happens to the lense?

Back 26

becomes spherical, see close objects

Front 27

When the ciliary muscle relaxes, what happens to the lense?

Back 27

flattens, increasing focal distance

Front 28

The retina contains what two things?

Back 28

rods and cones

Front 29

In the ear, what is the tympanic membrane?

Back 29

the eardrum, begins the middle ear

Front 30

The middle ear contains what three small bones?

Back 30

the malleus, incus, and stapes

Front 31

In the semicircular canals, what controls balance?

Back 31

hair cells

Front 32

Golgi apparatus

Back 32

A series of flattened, membrane bound sacs that organize proteins once they are synthesized.

Front 33

Secretory vesicles

Back 33

Release content through exocytosis

Front 34

Lysosomes

Back 34

Contain hydrolytic enzymes that digest waste in the cell.

Front 35

Smooth ER

Back 35

most phospholipids and triglycerides are synthesized here.

Front 36

Actin

Back 36

Major component of microfilaments

Front 37

Endosymbiont theory

Back 37

States the mitochondria have evolved from a symbiotic relationship between ancient prokaryotes and eukaryotes.

Front 38

Cristae

Back 38

Folded, inner membrane of the mitochondria

Front 39

All of the following are composed of microtubules EXCEPT: tail of sperm cell, spindle apparatus, cilia of fillopian tube, flagella of bacteria

Back 39

flagella of bacteria (made from protein flagellin)

Front 40

The nucleolus disappears during which phase of mitosis?

Back 40

Prophase

Front 41

Which of the following is NOT membrane bound: golgi body, nucleus, smooth ER, ribosome

Back 41

Ribosome

Front 42

Dendrites

Back 42

receive signal to be transmitted

Front 43

Axon

Back 43

carries the signal away from the cell

Front 44

Action potential

Back 44

disturbance in the electric field across the membrane of a nueron

Front 45

Resting potential

Back 45

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

Front 46

Sodium/potassium pump

Back 46

(see page 85 and know diagram). Creates action potential

Front 47

Depolarization

Back 47

When the membrane reverses polarity and so that it is positive on the inside and negative on the outside

Front 48

repolarization

Back 48

When K flows out of the cell, making the inside more negative.

Front 49

hyperpolarization

Back 49

when the inside becomes even more negative during resting potential

Front 50

In order to create an action potential, the stimulus must be greater than the _____ _____.

Back 50

Threshold stimulus

Front 51

Chemical synapse

Back 51

A unidirectional synapse that uses Ca2+ channels and receptor proteins. A common synapse found in the body

Front 52

Electrical synapse

Back 52

Faster than chemical synapse and can transmit signals in both directions, but less common in the body. Found only in cardiac muscle, visceral smooth muscle, and few nuerons in the central nervous system.

Front 53

Brownian motion

Back 53

random movement of molecules. In nuerotransmitters, this occurs across the synaptic cleft.

Front 54

Schwann cells

Back 54

produce myelin which insulates the axon in sheaths

Front 55

put the following in order for the normal the normal direction of a signal in transmission: axon, cell body, dendrite

Back 55

dendrite, cell body, axon

Front 56

Sympathetic nervous system

Back 56

branch of the autonomic nervous system that activates the "fight or flight" response. Increases heart rate and slows digestive system.

Front 57

parasympathetic nervous system

Back 57

branch of the ANS; "rest and digest"; slows heart rate and increases excretory activity

Front 58

repolarization

Back 58

When K flows out of the cell, making the inside more negative.

Front 59

hyperpolarization

Back 59

when the inside becomes even more negative during resting potential

Front 60

In order to create an action potential, the stimulus must be greater than the _____ _____.

Back 60

Threshold stimulus

Front 61

Chemical synapse

Back 61

A unidirectional synapse that uses Ca2+ channels and receptor proteins. A common synapse found in the body

Front 62

Electrical synapse

Back 62

Faster than chemical synapse and can transmit signals in both directions, but less common in the body. Found only in cardiac muscle, visceral smooth muscle, and few nuerons in the central nervous system.

Front 63

Brownian motion

Back 63

random movement of molecules. In nuerotransmitters, this occurs across the synaptic cleft.

Front 64

Schwann cells

Back 64

produce myelin which insulates the axon in sheaths

Front 65

put the following in order for the normal the normal direction of a signal in transmission: axon, cell body, dendrite

Back 65

dendrite, cell body, axon

Front 66

Sympathetic nervous system

Back 66

branch of the autonomic nervous system that activates the "fight or flight" response. Increases heart rate and slows digestive system.

Front 67

parasympathetic nervous system

Back 67

branch of the ANS; "rest and digest"; slows heart rate and increases excretory activity

Front 68

acetylcholine

Back 68

nuerotransmitter used by parasympathetic nervous system and ANS

Front 69

Sympathetic nervous system uses these two neurotransmitters

Back 69

epinephrine (adrenaline) and norepinephrine (noradrenaline)

Front 70

The lower brain consists of what four specific parts and what is its function?

Back 70

Medulla, hypothalamus, thalamus, cerebellum; integrates subconscious activities, such as respiratory system, arterial pressure, emotions, and reaction to pain or pleasure.

Front 71

Higher brain

Back 71

consists of cerebrum which acts to store memories and process thoughts

Front 72

Diagram of eye (p.97)

Back 72

study

Front 73

Diagram of ear (p.99)

Back 73

study