AP 1 Exam 3

Define muscle fatigue

Fatigue is a failure of the muscle to sustain force in a prolonged contraction or to reattain force in repeated contractions.

Which of the following bone belongs to the appendicular skeleton?

clavicle

These bones form the pectoral girdle.

clavicle and scapula

Which of the following bone markings helps form joints?

head

The female pelvis is ________ than the male pelvis.

heavier

Which of the following is a hinge joint?

interphalangeal

Vertebrae belong to this category of bones.

irregular

These keystone bones of the face contact all other facial bones except the mandible.

maxillae

The midline suture marking the articulation of the two parietal bones is called the ________ suture.

sagittal

Which joint in the figure is capable of multiaxial movement?

shoulder

The hypophyseal fossa of the sella turcica, surrounds the pituitary gland, and is a part of the ________ bone.

sphenoid

The structural classification of joints is based on ________.

the type of connective tissue between the articulating bones

Using the functional classification of joints, the intervertebral joint between bodies of adjacent vertebrae is a(n) ________ joint.

amphiarthrotic (slightly movable)

The __________ skeleton consists of bones that surround the body's center of gravity.

axial

The hip joint is an example of a __________ synovial joint.

ball-and-socket

A long bone consists of a shaft composed of ________ and an end composed of ________.

compact bone, spongy bone covered by compact bone

Sutures, which have their irregular edges of bone joined by short fibers of connective tissue, are an example of __________ joints.

fibrous

__________ bones are generally thin and have a layer of spongy bone between two layers of compact bone.

flat

Which movement decreases the angle between articulating bones?

flexion

This is a passageway for blood vessels and nerves.

foramen

A trochanter is a ________.

large, irregularly-shaped projection

The hand consists of three groups of bones. The carpals make up the wrist. The __________ make up the palm, and the phalanges make up the fingers.

metacarpals

Which of the following bones belongs to the axial skeleton?

sternum

Which of the following is NOT an example of a fibrous joint?

symphysis

Structural classification of joints includes fibrous, cartilaginous, and __________ , which have a fluid-filled cavity between articulating bones.

synovial

Using the structural classification of joints, the shoulder is a ________ joint.

synovial

The functional classification of joints is based on __________.

amount of movement allowed by the joint

Define each of the functional classification for joints and identify examples of each of the following articulations shown in your textbook: synarthrosis, diarthrosis, amphiarthrosis

- synarthrosis: an immovably fixed joint between bones connected by fibrous tissue (for example, the sutures of the skull) - diarthrosis: is a joint classification that is used when considering joint function (degree of movement) - amphiarthrosis: a joint in which the surfaces are connected by disks of fibrocartilage, as between vertebrae

Identify the three ways in which ATP is regenerated during skeletal muscle contraction and link the pathway to light, moderate and peak activities.

1. Direct Phosphorylation of ADP by creatine phosphate. 2. Anaerobic pathway (AKA: Glycolysis) 3. Aerobic Respiration.

Explain how muscle fibers are stimulated to contract by describing events that occur at the neuromuscular junction.

Every skeletal muscle fiber in every skeletal muscle is innervated by a motor neuron at a NMJ. Excitation signals from the motor neuron are the only way to functionally activate muscle fibers to contract. Every skeletal muscle fiber is supplied by a motor neuron at the NMJ.

Define motor unit and muscle twitch and explain how smooth, graded contractions of a skeletal muscle are produced.

Motor unit: consists of one motor neuron and all the muscle fibers it innervates or supplies. Muscle twitch: is a motor unit's response to a single action potential of its motor neuron. the muscle fibers contract quickly and then relax. every twitch myogram has three distinct phases

Identify the muscle used in respiration, inhalation versus exhalation

Muscles that helpful in expanding the thoracic cavity are called the inspiratory muscles because they help in inhalation, while those that compress the thoracic cavity are called expiratory muscles and they induce exhalation. (diaphragm)

Identify the functions of the skeletal system.

Provides support, protects internal organs, allows your body to move, and stores + produces materials that your body needs.

Briefly describe the steps of a cross bridge cycle.

The cross bridge cycle can be broken down as follows: Hydrolysis of ATP to ADP and Pi, with products still covalently bonded to myosin, cause it to enter an energised state. Cross bridge binds to actin. It undergoes a conformational change. ADP and Pi are released.

Compare the fetal skull to the adult skull in terms of number of bones and types of joints

The main difference between pediatrics vs adult is in the size of the infant skull versus that of an adult skull. Compared to a fully developed skull where the facial portion is about half that of the cranium, in a newborn baby, the facial portion is about 1/8th that of the cranium. This makes the fetal cranium look large compared to the facial bone area. An adult skull is made of 8 cranial bones and 14 facial bones totaling 22 bones. The skull bones are also connected together by sutures due to the process of ossification (metopic suture, coronal suture, sagittal suture, lambdoid suture).

Describe the sliding filament model of muscle contraction.

The sliding filament model describes the process used by muscles to contract. It is a cycle of repetitive events that causes actin and myosin myofilaments to slide over each other, contracting the sarcomere and generating tension in the muscle.

All of the following are short bones except ________.

phalanges

Describe the importance of temporal (wave) summation and motor unit recruitment allow smooth, graded skeletal muscle contractions

wave summation contributes to contractile force, but its primary function is to produce smooth, continuous muscle contractions by rapidly stimulating a specific number of muscle cells. it also controls the force of contraction more precisely.