Exercises Lesson

REQUIREMENT. The following exercises are to be answered by completing the incomplete statements.

After you have completed all the exercises, turn to "Solutions to Exercises" at the end of the lesson, and check your answers.

1. The neuron is also called a nerve_. It is the c_ing unit of the nervous system. It is specialized to be_ble and transmit s_s, or i_s.

2. The three major subdivisions of the human nervous system are the c_

nervous system, the p_nervous system, and the a_nervous system.

3. A neuron is the nerve cell_y plus all of its p_s and coverings.

A nerve is a collection of neuron_s together and (within) (outside of)

the CNS.

A fiber tract is a collection of neuron_s together and (within) (outside of)

the CNS.

A ganglion is a collection of nerve cell_s together and (within) (outside of)

the CNS.

A nucleus is a collection of nerve cell_together and (within) (outside of)

the CNS.

4. The human nervous system is supplied with special junctions called_s.

5. In general terms, the human nervous system can be compared to a_r.

Sensory information is the put, which is c_ed along with previously stored information. Once a decision has been reached by the central portion, there is an put of commands to the e_or organs (muscles and/or glands).

6. The brainstem is a primary c_ing center of the human nervous system.

The cerebellum is the primary coordinating center for_e actions. Here, patterns of movement are properly i_ed. Also, the cerebellum is very much involved in the_al equilibrium of the body.

The newest development of the brain is the m.

7. The autonomic nervous system (ANS) is that portion of the nervous system concerned with commands for_th muscle tissue,_c muscle tissue, and

For most of us, the control of the visceral organs is_c, that is, without conscious control.

8. The ANS is organized into two major subdivisions--the s_c and p_c nervous systems. The first of these is also known as the t_-l outflow. The second is also known as the c_-s_outflow.

If one of these subdivisions stimulates an organ, the other will i_t it. The interplay of the two subdivisions helps visceral organs to function within a stable _m. This tendency is called_s.

Under conditions of stress, the sympathetic nervous system mobilizes all of the

_y-producing structures of the body. For example, it makes the heartbeat

(faster) (slower). Later, as equilibrium is restored, the parasympathetic nervous system has the (same) (opposite) effect.

9. The neurons are alined in sequences to form c_ts. The transmission of information along a neuron is_cal in nature. Crossing the gap between one neuron and the next is a chemical called a_r.

10. Neurons are able to concentrate_tive ions inside and_tive ions outside of the cell membrane. When the neuron is not actually transmitting, this process produces the_g_J.

11. When the polarity of ions is disrupted by a stimulus, that location on the cell membrane is said to be_ized. The restoration of the original polarity is called re_. At the same time, adjacent areas are depolarized. Thus, there is a wave of d_/r_along the length of the neuron.

12. The speed of an impulse is proportional to the_ness of the neuron process.

Transmission is fastest in the_est neurons.

13. Together, the gap and the "connecting" membranes between two successive neurons are called the_. The gap itself is called the_c_t.

Containing specific amounts of neurotransmitter are_c_les in the terminal bulb of the first neuron. When an impulse reaches the bouton, the vesicles are stimulated to release their_r. This substance passes through the

_c membrane, across the synaptic cleft, and to the_c membrane.

Since this process consumes much energy, the bouton contains many well-developed

14. The neuromuscular junction is the "connection" between a_r neuron and a s_d_e fiber. It is nearly identical to a_e. However, the surface of the postsynaptic membrane is in a series of longitudinal_s. This greatly increases the s_a_receptive to the ACH.

The group of striated muscle fibers innervated by one motor neuron is called the motor_. Fewer muscle fibers per motor unit result in_r movements. More muscle fibers per motor unit result in_movements.

15. The simplest reaction is called a_, defined as an_c reaction to a stimulus.

16. A pathway of the human nervous system is the series of neurons or other structures used to_t an item of information. In general, we consider two major types of pathways--the general_y pathways and the_r pathways.

At some specific level in the neuraxis, all of these pathways cross to the opposite side. Each crossing is called a_tion. Thus, the right cerebral hemisphere communicates with the_half of the body. The left cerebral hemisphere communicates with the_half of the body.

17. The general senses include_q,_ch, t_e, and pro_q ("body_e").

A general sensory pathway extends from the point where the stimulus is received to the central gyrus (fold) of the cerebral hemisphere. This gyrus is the site of conscious sensation of a stimulus.

Corresponding to each location in the body, there is a specific location in the _l gyrus.

18. Pain is an ancient protective mechanism which generally helps us to avoid

_y. Endorphins are chemicals found naturally within the body which tend to block the sensation of_.

The pain receptor is not a specific receptor organ. It is referred to as a_

nerve ending.

19. The body has two different mechanisms for sensing temperature. Detecting warmth and cold in the periphery of the body are specific sensory_s.

Special heat-sensitive neurons in the hypothalamus detect increases in the temperature of the_.

20. The pacinian corpuscles are typical of the receptors which detect_p_re.

21. Another term for muscle sense is p_n. For this, there is a special receptor organ to monitor the_h of the muscle. These receptor organs are called muscle s_s or s_h receptors. They detect relative muscle J_.

Another stretch receptor associated with the skeletal muscle is the_i_n organ. As its name implies, this organ is located within the_of the muscle. It detects relative muscle t_.

22. The CNS receives information through the_pathways and collates this information against information stored in_. This results in a_n. If the decision is to do something, then the CNS sends out commands through the_

pathways to the_r organs.

23. We usually consider two general motor pathways--the_dal and the e_da] motor pathways.

24. A pyramidal motor pathway is primarily concerned with_ional ( ary)

control of body parts, particularly with the fine movements of the_s.

The pyramidal motor pathway begins in the p_l gyrus of the cerebral hemisphere. As we have already seen, the neurons making up the precentral and postcentral gyri are arranged in a pattern corresponding to the various_ts of the body to which they are connected.

Immediately below the pyramids, the axons_s to the opposite side of the

CNS. Thus, the left cerebral hemisphere commands the_side of the body, and the right cerebral hemisphere controls the_side of body.

25. The extrapyramidal motor pathways are concerned with_c (D_l)

control of body parts. This particularly includes patterned, sequential_ts or a_ns. The cerebellum plays a major role in extrapyramidal pathways. The cerebellum is the major center for c_ing the patterned sequential actions of the body, such as w_iDg

26. The human nervous system can be thought of as a series of_ps or_ls.

Each level is more_x than the level just below. No level is completely over d by upper levels, but each level is c_d or g_d by the next upper level as it functions.

The simplest and lowest level of control is the_arc. Producing a wider reaction to a stimulus are_d reflexes.

27. Nuclei in the medulla of the hindbrainstem control the_l activities of the body, such as r_d,_t_t, etc.

The reticular formation of the brainstem has a f tory area and an i_tory area. This control area produces_p or_ness.

The thalamus is a group of nuclei found together in the_stem. The thalamus is the major_y center of s_y inputs.

The hypothalamus is a higher control center for_l activities of the body.

28. The cerebellum is the primary center for the i_tion and_l of patterned, sequential_ns of the body.

29. In humans, the highest level of control is localized in the_. Localized at this level are c_s sensation and_nal motor activity.

The visceral level within the cerebrum is concerned with_activities of the body, as related to f_t-or-f_t,_r, and other emotions.

The second level of the cerebrum is concerned with st_ed patterns of muscle activity.

The third level of the cerebrum is the (thinking) occurs, and unique, brand-new nal level. Here, c s can be created.

30. The precentral gyrus is Brodmann's area number_. The center for hearing is

Brodmann's area number_.

31. In right-handed individuals, the left cerebral hemisphere is said to be_t over the right cerebral hemisphere. For most individuals, an injury to the_t cerebral hemisphere is more serious.

32. Memory is the faculty which enables an individual to store and retrieve factual items such as s_tions, i_sions, f_s, and i_s. All sensory inputs are collated against these stored items in order to arrive at an appropriate d_n for a_n .

33. There are at least two types of memory--_t-term memory and_-term memory.

Short-term memory is usually limited to about_bits of information.

A portion of the cerebral cortex is thought to be important in transferring information from_-term memory to_-term memory. It is called the h_s.

What is the effect on learning if the hippocampus is nonfunctional?

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Essentials of Human Physiology

Essentials of Human Physiology

This ebook provides an introductory explanation of the workings of the human body, with an effort to draw connections between the body systems and explain their interdependencies. A framework for the book is homeostasis and how the body maintains balance within each system. This is intended as a first introduction to physiology for a college-level course.

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