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Repolarization of a cell membrane (muscle cell or neuron) is accomplished by the

ID: 98651 • Letter: R

Question

Repolarization of a cell membrane (muscle cell or neuron) is accomplished by the opening of which type of channel?

sodium

potassium       

glucose           

calcium

Fertilization usually occurs in the  

vagina             

ovaries            

testicles                      

fallopian tubes/oviducts/uterine tubes           

uterus

Which of the following receives incoming sensory input and then relays it to the correct location in the cerebrum?

thalamus         

hypothalamus

hippocampus  

midbrain

The component of the autonomic nervous system that is responsible for the flight or fight response is the

central nervous system (CNS)           

somatic nervous system                     

parasympathetic nervous system       

sympathetic nervous system

An infectious disease that has spread world-wide would be a(n)

outbreak         

pandemic                    

epidemic

Sperm have an enzyme containing structure called a(n) ________ which assists with penetration of the egg.

follicle            

epididymus                

acrosome                    

zona pellucidum

An inhibitory neurotransmitter binds to ligand gated _______ channels.                     

sodium           

calciu              

potassium                   

iron

The basic functional unit of a skeletal muscle contraction is called the

T-tubule                      

fascicl             

osteon             

sarcomere

The substance tissue plasminogen activator (t-PA) can be administered to an individual in order to

stop an asthma attack             

dissolve a blood clot              

treat cancer                 

lower blood cholesterol levels

An individual who is in the chronic phase (category B) of HIV infection would

have some symptoms of a suppressed immune system (fever, fatigue)        

would be hospitalized for opportunistic infections (pneumonia                    

have some symptoms, but would not be able to transmit the disease           

have no symptoms

Explanation / Answer

The repolarization phase usually returns the membrane potential back to the resting membrane potential. The efflux of K+ ions results in the falling phase of an action potential. The ions pass through the selectivity filter of the K+ channel pore.

Fertilization occurs in the fallopian tubes/oviducts/uterine tubes

The hypothalamus is a part of the brain that has a vital role in controlling many bodily functions including the release of hormones from the pituitary gland.

The sympathetic nervous system originates in the spinal cord and its main function is to activate the physiological changes that occur during the fight-or-flight response. Thiscomponent of the autonomic nervous system utilizes and activates the release of norepinephrine in the reaction.

A pandemic is a global disease outbreak. HIV/AIDS is an example of one of the most destructive global pandemics in history.

Acrosome contains the enzymes that break down the outer membrane of the ovum, called the zona pellucida, allowing the haploid nucleus in the sperm cell to join with the haploid nucleus in the ovum.

inhibitory neurotransmitters cause an opening of ligand-gated potassium ion channels which leads to a local hyperpolarization (more negative than normal). This is known as a Inhibitory Postsynaptic Potential (IPSP) because it’s going to be LESS likely to throw off an action potential.When an inhibitory NT activates the receptor site, it causes additional potassium channels to open which may cause potassium ions to flow out of the cell and if additional positively charged potassium ions flow out of the cell, the inside of the cell will become more negative.

A sarcomere is the basic unit of muscle contraction of striated muscle tissue.

Tissue plasminogen activator is the activators of plasminogen and results in the breakdown of blood clots (fibrinolysis)

An individual who is in the chronic phase (category B) of HIV infection would have some symptoms of a suppressed immune system (fever, fatigue) .