Critical Thinking Test 2

Question 1

J.R. was riding his motorcycle across the Big Span Bridge when he had a collision with a nearsighted seagull. In the resulting crash, J.R. crushed his left leg, fracturing both leg bones; snapped the pointy distal end of his lateral forearm bone; and broke the most lateral and proximal bone in his wrist. The seagull flew off when the ambulance arrived. Name the bones that J.R. broke.

Answer 1

J.R. fractured his tibia and fibula, the styloid process of the radius, and the scaphoid.

Question 2

You are starting a class in forensic anatomy. The instructor gives you and your lab partner two complete sets of bones of adult humans. Your assignment is to determine which set of bones is a male and which is a female. What characteristics will you use to determine the gender of the skeletons?

Answer 2

You can compare the sizes of long bones, especially the articular ends, which tend to be larger and thicker in males. Bumps, lines, tuberosities, and ridges for muscle attachments are also typically more pronounced in males. There should be differences in the pelvic bone structure. The female pelvis should be wider and shallower and have more space in the pelvic inlet and outlet for childbirth.

Question 3

Old Grandma Olga is a tiny, stooped woman with a big sense of humor. Her favorite movie line is from The Wizard of Oz, when the wicked witch says, “I’m melting.” “That’s me,” laughs Olga, “melting away, getting shorter every year.” What is happening to Grandma Olga?

Answer 3

Due to her age and gender, Olga probably has osteoporosis. Bone loss is due to increased calcium loss and decreased production of growth hormone and estrogen. Shrinkage of the vertebrae results in hunched back and loss of height.

Question 4

During the volleyball game, Kate jumped, twisted, spiked, scored, and screamed! She couldn’t put any weight on her left leg. X-rays revealed a fracture of the proximal tibia. In layman’s terms, what is the location of Kate’s fracture? What are the body’s requirements for bone healing?

Answer 4

Kate fractured the top (under the kneecap) of the larger of the two leg bones. The body requires calcium, phosphorus, magnesium, vitamins A, C, and D, hGH and other hormones, and protein for bone matrix in order for Kate’s injury to heal.

Question 5

After your second A & P exam, you dropped to one knee, tipped your head back, raised one arm over your head, clenched your fist, pumped your arm up and down, and yelled “Yes!” Use the proper terms to describe the movements undertaken by the various joints.

Answer 5

Flex the knees, flex the hip (on the side with knee up), hyperextend the neck, flex fingers, flex and extend at elbow and shoulder, and depress mandible.

Question 6

Aunt Rosa’s hip has been bothering her for years, and now she can hardly walk. Her doctor suggested a hip replacement. “It’s one of those synonymous joints,” Aunt Rosa explained. What type of joint is the hip joint? What types of movements can it perform?

Answer 6

The hip joint is a diarthrotic, synovial joint of the ball-and-socket type formed by the head of the femur fitting into the acetabulum of the hip bone. The movements are extension/flexion, abduction/adduction, rotation, and circumduction.

Question 7

Remember Kate, the volleyball player from Chapter 6? Her cast finally came off today. The orthopedist tested her knee’s range of motion and declared that the ACL appeared to be intact. What is the ACL? How does the ACL contribute to the knee joint’s stability?

Answer 7

The ACL is the anterior cruciate ligament. It connects the tibia to the femur, running posteriorly and laterally. The ACL works along with other internal and external ligaments to stabilize the knee joint.

Question 8

Grandma’s in good health but has had more difficulty walking the past year. She doesn’t complain, but simply states “It’s the curse of being 82! I just need to buy me some new legs!” Why do you suspect she is having trouble walking? Are “new legs” an option?

Answer 8

Grandma is likely suffering from osteoarthritis—the most common degenerative joint disease in the elderly. Although Grandma can’t buy “legs,” she could discuss with her physician the pros and cons of arthroplasty—the replacement of damaged joints with artificial joints.

Question 9

The newspaper reported several cases of botulism poisoning following a fund-raiser potluck dinner for the local clinic. The cause appeared to be three-bean salad “flavored” with the bacterium Clostridium botulinum. What would be the result of botulism poisoning on muscle function?

Answer 9

The skeletal muscles will not contract without receiving a signal from the neurotransmitter acetylcholine. Since release of ACh is blocked, skeletal muscles will not function.

Question 10

Ali’s nephew was squealing with laughter. She was entertaining him by sticking her thumb in her pursed lips, raising her eyebrows, pumping her arm up and down, and puffing her cheeks in and out. Name the muscles Ali was using to maneuver her face.

Answer 10

Ali used the orbicularis oris (puckering), frontalis (eyebrows), zygomaticus (cheeks), and buccinator (cheeks).

Question 11

When her cast finally came off after six long weeks, Kate thought she’d be all set to rejoin her volleyball team, but now her left thigh is only half the size of her right. Explain what happened to her thigh and what she needs to do to get back in the game.

Answer 11

Kate’s leg muscles atrophied from loss of myofibrils due to lack of use of the muscles. Kate will need to exercise in order to increase muscle size by building up myofibrils, mitochondria, and sarcoplasmic reticulum.

Question 12

While watching the Olympic track-and-field trials on television, your sister asked you why the sprinters have such large leg muscles compared to the marathon runners. How could you explain this observation?

Answer 12

The sprinters have higher proportions of fast glycolytic muscle fibers, which are large in diameter as compared to the marathon runners, who would have a higher proportion of fast oxidative-glycolytic fibers with smaller diameters. Sprinters would have training regimens that would tend to encourage muscle hypertrophy, while the marathon runners’ training would encourage greater respiratory and cardiovascular changes but not an increase in muscle mass.

Question 13

The buzzing of the alarm clock awoke Rodrigo. He stretched, yawned, and started to salivate as he smelled the brewing coffee. List the divisions of the nervous system that are involved in each of these activities.

Answer 13

Smelling coffee and hearing an alarm are somatic sensory, stretching and yawning are somatic motor, salivating is autonomic (parasympathetic) motor.

Question 14

Prior to surgery, Marga was given a curare-like drug that temporarily “paralyzed” her muscles so that she could be more easily intubated and would not move during surgery. What is the neurotransmitter involved and how do you think the drug prevents skeletal muscle contraction?

Answer 14

Acetylcholine is the excitatory neurotransmitter released by motor neurons to initiate muscle contraction. The drug given to Marga blocks the receptor sites on the muscle fibers so ACh cannot attach and stimulate the muscle cells.

Question 15

Sarah really looks forward to the great feeling she has after going for a nice long run on the weekends. By the end of her run, she doesn’t even feel the pain in her sore feet. Sarah read in a magazine that some kind of natural brain chemical was responsible for the “runner’s high” that she feels. Are there such chemicals in Sarah’s brain?

Answer 15

Neuropeptides such as endorphins are found in the brain. They are related to feelings of pleasure and are natural painkillers.

Question 16

The pediatrician was trying to educate the anxious new parents of a six-month-old baby. “No, don’t worry about him not walking yet. The myelination of the baby’s nervous system is not finished yet.” Explain what the pediatrician means by this reassurance.

Answer 16

A myelin sheath increases the speed of nerve impulse conduction (propagation). Because myelination is not complete in infants, their responses are slower and less coordinated than in older children.

Question 17

After a few days of using her new crutches, Kate’s arms and hands felt tingly and numb. The physical therapist said Kate had a case of “crutch palsy” from improper use of her crutches. Kate had been leaning her armpits on the crutches while hobbling along. What caused the numbness in her arms and hands?

Answer 17

The brachial plexus runs through the axillary region and supplies the arm and hands. Kate’s weight has put pressure on the brachial plexus and interrupted nerve impulse transmission.

Question 18

A few days after a minor car accident, Teri suffers from vision problems and is feeling pressure in the back of her head. After a series of diagnostic procedures, her physician indicates that Teri immediately needs to have “water drained from her brain.” Explain to Teri what the surgeon plans to do and why she might have “water on her brain.”

Answer 18

Teri suffered a head injury from her car accident that has caused a blockage of CSF circulation in the subarachnoid space near the occipital lobe, where visual function is centered. The accumulating CSF will be drained with a shunt to prevent permanent and possibly life-threatening brain damage.

Question 19

An elderly relative suffered a stroke and now has difficulty with the movement of her right upper limb. She is also working with a therapist due to some speech problems. What areas of the brain were damaged by the stroke?

Answer 19

The primary motor area in the left precentral gyrus and Broca’s area in the left frontal lobe were damaged by the stroke. Both of these areas are in the cerebral cortex.

Question 20

Lynn flicked on the light when she heard her husband’s yell. Kyle was bouncing on his left foot while holding his right foot in his hand. A pin was sticking out of the bottom of his foot. Explain Kyle’s response to stepping on the pin.

Answer 20

A receptor in Kyle’s foot detected the pain from the pin. The impulse traveled along a sensory nerve to the spinal cord, which passed the signal along to a motor neuron. The motor neuron(s) stimulated the muscles in Kyle’s leg muscles to contract, resulting in a withdrawal reflex.

Question 21

It’s Thanksgiving and you’ve just eaten a huge turkey dinner with all the trimmings. Now you’re going to watch the big game on TV, if you can make it to the couch! Which division of the nervous system will be handling your body’s post-dinner activities? Give examples of some organs and the effects on their functions.

Answer 21

The parasympathetic division of the ANS directs rest-and-digest activities. The organs of the digestive system will have increased activity to digest food, absorb nutrients, and defecate wastes. In the relaxed condition, the body will also exhibit slower heart rate and airway constriction.

Question 22

It is your turn to give an in-class oral presentation. You break into a sweat, heart pounding, with a mouth so dry you can barely speak. You notice lingering effects on your body even after you’ve returned to your seat. Describe what kind of reaction is occurring in your body.

Answer 22

The anxiety of giving the presentation has activated your sympathetic nervous system. Even though you are not in physical danger, your body has initiated the fight-or-flight response, resulting in the symptoms you experienced. The release of epinephrine and norepinephrine from the adrenal medullae ensures that the effects don’t go away any time soon!

Question 23

Taylor was watching a scary late-night horror movie when she heard a door slam and a cat’s yowl. The hair on her arms rose and she was covered with goose bumps. Trace the pathway taken by the impulses from her CNS to her arms.

Answer 23

The goose bumps are a sympathetic nervous system response. The cell bodies of sympathetic preganglionic neurons are in the thoracolumbar (T1-L2) segments of the spinal cord; their axons exit in the anterior roots of spinal nerves and extend out to a sympathetic ganglion. From there, postganglionic neurons extend to hair follicle smooth muscles (arrector pili), which produce goose bumps when they contract.

Question 24

In the novel The Hitchhiker’s Guide to the Galaxy, the character Zaphod Beeblebrox has two heads and therefore two brains. Is this what is meant by dual innervation? Explain.

Answer 24

Dual innervation refers to the innervation of most organs by both the sympathetic and parasympathetic divisions of the autonomic nervous system, not to the presence of more than one head.