Final Exam Flashcards
what is a synapse?
site of communication between a neuron and another cell
types of synapses
1) electrical
2) chemical
how do electrical synapses work?
- direct physical contact between cells
how do chemical synapses work?
- signal transmitted across a gap (synaptic cleft) by chemical neurotransmitters
what does the production of action potential depend on in chemical synapses?
- amount and type of neurotransmitter released
- sensitivity of postsynaptic cell
what are the steps of action potential in chemical synpases?
1) action potential arrives & depolarizes synaptic knob
2) synaptic vesicles are exocytosed & neurotransmitter molecules are released
3) neurotransmitter crosses synaptic cleft & binds to receptor
4) ion channels open, depolarizing membrane & producing a graded potential
5) neurotransmitter removed & depolarization ends
what are cholinergic synapses?
- synapses that use acetylcholine as a neurotransmitter
- most common type of synapse
how does a cholinergic synapse work?
1) AP depolarizes synaptic knob
2) Ca2+ channels open
- Ca2+ enter
- Ach exocytosed
3) Ach binds to receptor
- Na+ enters
- depolarize membrane
4) AchE breaks down Ach (acetate + choline)
what are the 2 types of neurotransmitters?
1) excitatory
2) inhibitory
how do excitatory neurotransmitters work?
- cause depolarization of post-synaptic membranes
(excitatory postsynaptic potential = EPSP)
how do inhibitory neurotransmitters work?
- cause hyperpolarization of postsynaptic membranes
(inhibitory postsynaptic potential = IPSP)
effect on postsynaptic membrane depends on what?
the RECEPTOR
what are the 2 types of summation of postsynaptic potential (PSPs)?
1) spatial
2) temporal
do fewer synapses mean faster response?
yes
what is synaptic fatigue?
- occurs when neurotransmitter cannot be recycled fast enough to meet demands of intense stimuli
what are some major neurotransmitters?
- norepinephrine (NE)
- dopamine
- serotonin
what are some characteristics of norepinephrine?
- released by adrenergic synapses
- excitatory & depolarizing effect
- brain & portions of ANS
what are some characteristics of dopamine?
- CNS neurotransmitter
- excitatory or inhibitory
- involved in Parkinson’s diseases, cocaine use
what are some characteristics of serotonin?
- CNS neurotransmitter
- affects attention & emotional states
what are the 2 types of electrical signals?
1) graded potentials
2) action potentials
what are graded potentials?
- affect only a small portion of a cell membrane
- allows communication over short distances
how do action potentials work?
- affect the entire surface of a cell membrane
- allow communication over long distances
what are the 3 phases of graded potentials?
1) resting
2) stimulation
3) depolarization
what are the 5 phases of action potentials?
1) resting
2) threshold
3) activation/depolarization
4) inactivation/repolarization
5) return to resting
how do signals work in graded potentials?
- vary with stimulus
- # of channels opened/closed
- time channel remains opened/closed
how do signals work in action potentials?
- all or none principle
- if depolarization reaches threshold, ion channels open & action potential occurs
what is the refractory period?
period of time during which another action potential cannot be generated
- begins with depolarization
- ends when repolarization is “almost” complete
what are the 2 types of action potential propagation?
1) continuous
2) saltatory
what are characteristics of continuous action potential propagation?
- unmyelinated axons
- slower
- every portion of axon membrane must depolarize
what are the 4 steps of continuous propagation?
1) AP produced in initial segment
2) Local current depolarizes segment 2
3) AP produced in segment 2
4) Local current produced in segment 3
Cycle repeats
what are the 4 steps in saltatory propagation?
1) AP produced in initial segment
2) Local current depolarizes node 1
3) AP produced at node 1
4) Local current depolarizes node 2
Cycle repeats
what is the action potential frequency?
the greater the number of action potentials per second, the “stronger” the stimulus “feels”
what is transmembrane potential?
difference in electrical charge between the inside & outside of a cell membrane
- outside = POSITIVE
- inside = NEGATIVE
what is the difference in concentration levels of ions between the ECF vs ICF?
Outside
- high sodium (Na+)
- high chloride (Cl-)
Inside
- high potassium (K+)
- high proteins (-)
how does the Na+/K+ exchange pump work?
- moves 3 Na+ ions out for every 2 K+ in
- inside gets “less positive” or “more negative”
what are ion channels?
protein tunnels for specific ions
what are the major sections and subsections of the human brain?
1) Brainstem
- midbrain
- pons
- medulla oblongata
2) Diencephalon
- epithalamus
- thalamus
- hypothalamus
3) Cerebrum
4) Cerebellum
True or False: organs contain 2 or more tissues that work together to perform specific complex functions
True
True or false: a molecule is made up of a combination of 2 or more atoms
True
A(n) ____ plane separates the body into superior and inferior parts.
transverse
The word ____ implies an imaginary flat surface passing through the body
plane
A plane that passes through the structure at an angle is called
oblique
what best defines “superficial”?
On the outside
The directional term that means “in back of” or “toward the back surface” is
posterior
which system is responsible for providing protection, regulating body temperature, and being the site of cutaneous receptors?
Integumentary
the category of reactions in which larger molecules are broken down into smaller ones is known as
catabolism
at what level of organization is a tooth, which contains multiple tissue types?
organ level
how to accurately describe the organization of structures?
organs are made up of tissues, which are made up cells, which are made up of organelles and molecules
with the subject in anatomical position, one can best see the dorsum of the manus from a(n) ___ view
posterior
what is the anatomic term for the hip region?
coxal
an inguinal hernia is in the region of the…
groin
“Pollex” refers to the…
thumb
the bones of the vertebral column form a cavity called the…
vertebral canal
the anatomic term for the cheek is…
buccal
The limbs of the body are attached to the axis and make up the…
appendicular region
the axillary region is ___ to the pectoral region
lateral
the various chemical reactions that organisms carry out are collectively called…
metabolism
True or false: the central nervous system acts as the control center for the regulation of blood calcium & blood glucose
False
If carbon dioxide levels rise in the body, negative feedback mechanisms will trigger…
an increase in breathing so that carbon dioxide levels decline to the set point
the normal level at which a physiological variable is known as its…
set point
True or false: if your body temperature starts to decline, your body responds by exciting skeletal muscles so that you shiver and your temperature returns to normal. This is an example of negative feedback.
True
what is the correct order of the components of a homeostatic control system in proper order?
Stimulus, receptor, control center, effector
when you are exposed to bright light, cells in the retina detect the stimulus and send it to the brain for processing. The brain commands the iris to constrict and decrease pupil size. Which structure serves as a receptor in this system?
the retina
the primary function of serous fluid is…
to serve as a lubricant
the pleural cavity is the…
potential space between the 2 serous membranes surrounding a lung
the pericardium is a 2-layered serous membrane that…
encloses the heart
the serous fluid that helps in cardiac function is located…
in the pericardial cavity, between the parietal and visceral pericardial layers
with a specimen in anatomic position, you can best see the mediastinum with a ____ view
frontal
True or false: the antecubital region is proximal to the carpal region
True
which type of epithelial tissue would be the least protective?
simple squamous
when a small, polar solute binds to a membrane protein that then changes shape and transports the solute across the membrane, the process is known as…
carrier protein mediated diffusion
the sodium-potassium ATPase functions by performing…
primary active transport
the most abundant lipid of the membrane consists of a head and 2 tails. this type of lipid is…
a phospholipid
proteins that assist the movement of a substances across the membrane are called ____
transport
glycolipids are found on the…
outer layer of the cell membrane, and they help make the sticky sugar coating on its surface
consider a cell with a total internal solute concentration of 0.9%. Placing the cell in which bath solution would result in creation of the greatest osmotic pressure in the cell?
0.5% NaCl
movement of a substance from an area of higher concentration to one where it is less concentrated is known as…
diffusion
the sodium-potassium pump moves…
sodium out of the cell and potassium into the cell
which type of pump uses active transport process?
ion pump
Diffusion rate is fastest when the concentration gradient is…
steepest and temperature is highest
what is a type of a passive transport process?
osmosis
the uptake of cholesterol into cells is an example of…
receptor-mediated endocytosis
coupled transport that involves the moving of one substance against its concentration gradient by using energy from a second substance moving down its concentration gradient is known as…
secondary active transport
the release of neurotransmitter from a neuron is an example of…
exocytosis and it requires expenditure of ATP
what are the types of non-membrane-bound organelles?
- microtubule
- cytoskeleton
- centrioles
- ribosomes
- cilia
- microvilli
- proteasomes
what are the 3 general functions that cells must perform?
1) maintain shape
2) obtain nutrients
3) dispose of wastes
another name for intracellular fluid is…
cytosol
if the nutrient glycogen is found stored inside a cell, it is considered a(n)…
inclusion
the ____ is responsible for forming the outer, limiting barrier of a cell
plasma membrane
True or false: over time diffusion results in the even distribution of a substance throughout an area
True
True or false: materials tend to move less rapidly when their concentrations are significantly different between 2 compartments
False
True or false: most cells perform pinocytosis
True
True or false: all cells must obtain nutrients, form new chemical structures, and dispose of waste molecules
true
True or false: one example of a membrane-bound organelle is a ribosome
False
True or false: the centrosome is considered to be an inclusion
False
The folds of the internal membrane of a mitochondrion are called…
cristae
Removal of old organelles is via a process called…
autophagy
mucus is moved along the lining of the trachea by extensions from cell membrane known as…
cilia
Identify the organelle that provides enzymes for autolysis
Lysosomes
the ____ are responsible for synthesizing most of a human body cell’s ATP
mitochondria
in humans, the only cell that bears a flagellum is the ___ cell
sperm
which is NOT a membrane-bound organelle?
- nucleus
- mitochondria
- endoplasmic reticulum
- Golgi apparatus
- lysosomes
- peroxisomes
all of the choices are membrane-bound organelles
the term “codon” refers to
3 nucleotides that encode for a specific amino acid
the E site of a ribosome is where…
the tRNA exits the ribosome
During transcription…
an RNA molecule is formed as a DNA sequence is read
what is a required enzyme for the process of transcription?
RNA polymerase
True or false: DNA is the control center of the cell because it directs the synthesis of proteins, which are responsible for most cellular functions
True
The function of the nucleolus is to make…
the subunits of ribosomes
the nuclear envelope consists primarily of…
2 phospholipid bilayers
True or false: A little over 50% of the total amount of DNA in a human cell consists of genes
False
Because they produce ribosome subunits, one would expect to find large numbers of nucleoli in cells that synthesize…
proteins
what is NOT secreted by glands?
DNA
A ____ epithelium consists of a single layer of flattened cells attached directly to a basement membrane
simple squamous
the type of epithelium that lines the urinary bladder and may include some binucleated cells is called ____ epithelium
transitional
the lining of the air sacs in the lungs (alveoli) is comprised of what epithelium?
simple squamous
which type of epithelial tissue would be the least protective?
simple squamous
which type of epithelium is composed of multiple layers, including an apical layer containing tall, slender cells?
stratified columnar
which tissue type covers body surfaces and lines the inside of organs and body cavities?
epithelial
microscopic folds that extend from the apical surface of certain epithelia to increase the surface area for absorption and secretion are called…
microvilli
if you gently rub your thumb and forefinger together, each finger is contacting…
keratinized stratified squamous epithelium
you would most likely find goblet cells in what type of tissue?
epithelial tissue
what feature is NOT characteristic of epithelial tissue?
large amount of extracellular matrix
in what tissue would you expect to find very little, if any, extracellular matrix?
epithelial tissue
True or false: tight junctions provide direct passageways for substances to travel between neighboring cells
false
true or false: the lysosome is an example of a membrane-bound organelle
true
true or false: lysosome functions range from the digestion of materials ingested by the cell to the self-destruction of the cell
true
some bone interiors contain hemopoietic tissue, which functions in…
producing blood cells
in connective tissue, the extracellular matrix consists of…
protein fibers and ground substance
what feature of your ear accounts for its ability to regain its shape after it has been deformed or compressed?
the elastic fibers present in the ear’s cartilage
what is the most abundant protein in the body, forming about 25% of all body protein?
collagen
what unit of bone consists of a central canal (containing blood vessels, nerves, and lymph vessels) surrounded by concentric rings of calcified matrix?
osteon
which cellular feature is found both cartilage and bone?
lacuna
which type of connective tissue is found in the papillary layer of the dermis and contains all of the cell types of connective tissue proper?
areolar
where in the body would you expect to find a perichondrium?
covering cartilage
which primary tissue type would be represented by blood, body fat, ligaments and tendons, dermis of the skin, and the cartilage of some joints?
connective tissue
Plasma is…
a liquid ground substance containing dissolved proteins
True or false: the anatomic position allows all observers to have a common point of reference
true
