BIOL 3204 Exam 4

test questions, 3&4

What physiological change would you expect if you traveled to the mountains high above sea level?

decreased partial pressure of oxygen (PO2) in the alveoli

The ____ capillaries of the glomerulus allow most molecules to pass into the capsule, but ______ are retained and pass to the smaller efferents.

Fenestrated; erythrocytes

Bronchodilation can be stimulated by...

Epinephrine

Skeletal muscle Ca2+ signaling

Depolarization along the T-tubule causes voltage-gated Ca2+ channels to open on the sarcoplasmic reticulum

Smooth muscle Ca2+ signaling

Ca2+ entering the cell triggers the release of Ca2+ from the sarcoplasmic reticulum

Cardiac Muscle Ca2+ signaling

Depolarization along the T-tubule causes voltage-gated Ca2+ channels to open on the cell membrane

Of the 8-10L of fluid that enters the GI tract every day...

only about 150mL is excreted as part of the feces

Which molecule binds and activates platelets after a blood vessel has been injured?

Collagen

Where in the digestive system is mucus secreted?

The oral cavity; small intestine; stomach; large intestine

These vessels are the main site of variable resistance in the circulatory system:

arterioles

Which is NOT an accessory gland to the digestive system?

Enteric nervous system

Which of the following contributes to the asynchronous contraction of heart atria and ventricles?

Delay of action potential traveling from the SA node to the apex.

Which of the following is NOT true of cardiac function?

The CNS controls heart rate

The importance of the plateau phase of the action potential of contractile cells in...

preventing arrhythmia

The primary function of bile is to...

aid in the digestion of lipids

The primary exchange surface of the lungs is at the level of the...

alveoli

The uppermost part of the _____ is composed of skeletal muscle, while the lower 1/2 is entirely smooth muscle, which roughly corresponds to the respective voluntary and involuntary control of these sections

esophagus

What is primarily responsible for human inhalation and exhalation?

The contraction and relaxation of the diaphragm

Pre-historic insects could be _____, bc _____ atmospheric oxygen created a _____ concentration gradient.

Larger; more; steeper

Which section of the nephron is impermeable to water?

ascending Loop of Henle

Ventricles depolarize...

from the apex up

Autorhythmic cells....

are also called pacemakers because they set the heart rate

When the bladder becomes full, stretch receptors send signals via sensory neurons to the spinal cord. This causes...

opening of the internal sphincter; inhibition of the tonic stimulation that is normally contracting the external sphincter; parasympathetic neurons to fire, which triggers contraction of the smooth muscle of the bladder

Pulmonary arterial pressure is higher than the systemic arterial pressure (aorta).

False

Urine is carried to the urinary bladder by the...

ureters

The P wave of an ECG corresponds to...

the depolarization of the atria.

Which is NOT considered to be a primary function of the respiratory system?

Regulation of water balance

How does gas exchange occur in your body?

Passive diffusion

What best describes how alcoholic beverages affect your water balance?

Ethanol inhibits ADH, which leads to the production of large volumes of dilute urine

Smooth muscle cells

An autonomic neuron releases neurotransmitters that bind to receptors on the sarcolemma and generate an action potential. Cell membrane depolarization releases Ca2+ from the sarcoplasmic reticulum. Myosin binding sites are revealed on actin. Contraction occurs along the entire length of the myosin filament

Cardiac autorhythmic cells

The action potential is generated intrinsically via ion funny (IF) channels. Voltage-gated Ca2+ channels open in the cell membrane triggering rapid depolarization and IF channels close. Ca2+ channels close and K+ channels open. IF channels open.

Cardiac contractile cells

The action potential enters from an adjacent cell. Voltage-gated Na+ channels open causing rapid depolarization. Voltage-gated K+ channels open beginning cellular repolarization. Voltage-gated Ca2+ channels open. Ca2+ binds receptors in the SR. Ca2+ is released from the SR. Myosin binding sites are revealed in actin. The sarcomere contracts. Ca2+ channels close. Slow K+ channels open.

Skeletal muscle cells

The action potential is generated by neurotransmitters produced by a somatic motor neuron binding receptors in the sarcolemma. Voltage-gated Na+ channels open along the sarcolemma and depolarization causes voltage-gated Ca2+ channels to open along the T-tubules which are mechanically coupled on Ca2+ channels on the SR. Myosin binding sites are revealed on actin. The sarcomere contracts

At the SYSTEMIC capillaries, oxygen (O2) and carbon dioxide (CO2) move _____ their concentration gradients. ______ moves into the capillaries and ____ moves out of the capillaries.

down; Co2; O2

If the membrane of cardiac muscles in the sinoatrial (SA) node were more permeable to K+, you would predict:

heart rate will decrease

Veins carry de-oxygenated blood to the heart, except in the...

pulmonary system

Glucose is normally found in the _____, but absent from the ________.

filtrate; urine

In the stomach, the mucosal layer secretes H+ and Cl- ions. This is necessary because...

the digestive enzyme pepsin is only activated at very low pH

The inner lining of blood vessels is called...

endothelium

Compared to arteries, the velocity of blood flow through the capillaries is....

much slower

The sphincter (muscle valve) regulates passage if contents between the small and large intestine (colon)

ileocecal sphincter

Nearly 60 times your body's total water volume is filtered through the kidneys every day. How are we able to avoid dehydration?

Most of the components of plasma that are filtered are reabsorbed

Smooth muscle is present in the walls of....

arteries and veins, but not capillaries