PHYL 141L UNIT 4 QUIZZES/HW QUESTIONS

Name two types of photoreceptor cells

1. Rods 2. Cones

When the threshold is reached and voltage-gated Na+ channels open, the resulting change in membrane potential is known as a(n)

Action Potential

The principle that states that a stimulus either causes an action potential or does not cause an action potential is known as the

All-or-none principle

In the post-synaptic neuron, the receptors are located on __________

Cell bodies and Dendrites

Which structure is the dividing line between motor and sensory areas of the brain?

Central Sulcus

What are the ventricles filled with?

Cerebral Spinal Fluid (CSF)

What is white matter composed of?

Composed of Tracts, bundle of axons, that connect one part of the brain to another and to the spinal cord

Which structure in the eye is responsible for focusing light on the retina?

Cornea

What structure holds the two hemispheres together?

Corpus Callosum

When the inside of the membrane becomes less negative, the membrane potential is said to be

Depolarized

True or False A single graded potential can produce an action potential.

FALSE

True or false. K+ is the most important extracellular cation.

FALSE

Which lobe is hidden behind frontal and temporal lobes?

Insula

Which structure regulates how much light enters the eye?

Iris

During repolarization __________ is coming into the cell and __________ is coming out of the cell.

K+ is going out of the cell; Na+ is coming into the cell

Which of the following is the most important for establishing RMP?

Na+/K+ ATPase

Which lobe processes visual information?

Occipital lobe

The _________ is where neuronal axons pass through the posterior aspect of the eye.

Optic disc

Which layer of the meninges is most closely adhered to the brain?

Pia matter

Which portion of the eye contains photoreceptors?

Retina

True or false. During the absolute refractory period, a second stimulus (no matter how strong) will not excite the neuron.

TRUE

True or false. Na+ /K+ ATPase pumps 2K+ ions in and 3Na+ ions out of a cell per one ATP molecule.

TRUE

Which structure, illustrated in this specimen, is not present in humans?

Tapetum

Which lobe processes auditory information?

Temporal lobe

What is the most anterior and superficial structure of the eye?

The Fibrous layer

Choroid is part of the ____________ tunic (layer) of the eye

Vascular

What's the jelly like substance found inside the eye that helps maintain its shape?

Vitreous Humor - helps maintain its shape

If the accumulation of graded potentials in the trigger zone reaches threshold, the result is

Voltage-gated channels open