click below
click below
Normal Size Small Size show me how
Carolyn Santos
Human Physiology week 7-13
Question | Answer |
---|---|
The mechanisms that produce and maintain the resting membrane potential do so by producing a | slight excess of positive ions on the outer surface of the plasma membrane |
True or False. In a myelinated fiber, the action potential jumps from one node of Ranvier to the next. | True |
. The action potential seems to “leap” from node to node along a myelinated fiber. This type of impulse regeneration is called __________ conduction. | sensory |
The difference between sodium and potassium in the generation of action potential is that: | sodium causes depolarization of the cell membrane, and potassium causes repolarization of the cell membrane. |
When neurotransmitters from synaptic knobs stimulate a postsynaptic neuron in rapid succession, their effect can add up over a brief period to produce an action potential. This is called | temporal summation |
If the magnitude of the local depolarization surpasses a limit called the _____, voltage-gated Na+ channels are stimulated to open. | threshold potential |
Compared with the outside of the neuron, the inside has a(n) ____ charge. | negative |
The only ion(s) that can diffuse across a neuron’s membrane when the neuron is at rest is (are): | potassium |
During a relative refractory period: | the action potential can be initiated with a strong stimulus |
Which of the following is not one of the main chemical classes of neurotransmitters? | Triglycerides |
The fastest nerve fibers in the body can conduct an impulse that is how much faster than the slowest fibers in the body? | Almost 300 times faster |
The somatic motor system includes all the _____ motor pathways _____ the CNS. | voluntary; outside |
A reflex consists of either a muscle contraction or a | glandular secretion |
The groove between the frontal and parietal lobes of the cerebral cortex is the | central sulcus. |
htThe _____ is an extension of the great toe, with or without fanning of the other toes, in response to stimulation of the outer margin of the sole of the foot. | Babinski sign |
The part of the brain that assists in the maintenance of balance is the: | cerebellum |
Nerves that innervate the floor of the pelvic cavity and some of the surrounding areas are found in the _____ plexus. | coccygeal |
How does a dually innervated autonomic effector differ from a singly innervated autonomic effector? | A dually innervated effector receives input from both sympathetic and parasympathetic pathways. A singly innervated autonomic effector receives input from only the sympathetic division. |
The knee jerk can be classified as a segmental reflex because: | impulses that mediate it enter and leave the same segment of the cord. |
Dynamic equilibrium depends on the functioning of the | crista ampullaris. |
Which of the following statements is not true of the pineal gland? | Melatonin is stimulated by the presence of sunlight. |
The production of thyroid hormone is stimulated by another hormone from the: | anterior pituitary |
The sequence of auditory ossicles in the middle ear starting at the tympanic membrane and ending at the oval window is | malleus, incus, and stapes |
When a small amount of one hormone allows a second hormone to have its full effect, the phenomenon is called. | permissiveness |
Which two factors promote the return of venous blood to the heart? | blood-pumping action of respirations and skeletal muscle contractions |
A glycoprotein hormone that is secreted to increase oxygen concentration in the tissues is | erythropoietin |
The heart begins beating in the fetus at about what stage of development? | After about 4 weeks |
Molecules formed by the reactions of the complement cascade assemble themselves on the enemy cell’s surface, which results in | cytolysis |
Each cortical nodule is composed of packed lymphocytes that surround a less dense area called a | germinal center |
Lymphocytes that kill many types of tumor cells and cells infected by different kinds of viruses are known as | natural killer cells. |
Excessive fluid in the pleural cavity would be most likely to cause: | decreased vital capacity. |
Which of the following helps determine the amount of oxygen that diffuses into the blood each minute? | All of the above help determine the amount of oxygen that diffuses into the blood each minute. |
The vital capacity is equal to the sum of the: | inspiratory reserve volume, tidal volume, and expiratory reserve volume |
If the tidal volume of a given individual is 500 ml, then the anatomical dead space is approximately _____ ml. | 150 |
The symbol HbNCOOH– is used for: | carbaminohemoglobin. |
Dalton law states that the partial pressure of a gas in a mixture of gases is _____ to the total pressure of the mixture. | directly related to the concentration of that gas in the mixture and |
One hundred milliliters of arterial blood contains approximately what volume percent of oxygen? | 20% |
Which blood vessel carries absorbed food from the GI tract to the liver? | Portal vein |
The major site for the absorption of the end products of digestion is the: | small intestine |
Which phase(s) of gastric secretion is(are) stimulated by the sight, taste, and smell of food? | Cephalic phase |
The hormone that inhibits gastric muscle, slowing passage of food into the duodenum, is called: | gastric inhibitory peptide. |
When classified according to the kind of chemical reactions catalyzed, digestive enzymes are referred to as _____ enzymes. | hydrolyzing |