A&P Exam 4 (General)

fossa

shallow depression

first class lever

the fulcrum is between the effort and the load a first-class lever can produce either a mechanical advantage or disadvantage depending on whether the effort is closer to the fulcrum or the load is closer there are few first-class levers in the body example: the lever formed by the head resting on the vertebral column

meatus

tubelike passageway

What are the beneficial results of the association of venae comitantes with their corresponding artery? (V079)

- Countercurrent heat exchanger in which warm arterial blood warms cooler - venous blood returning to the heart Arteriovenous pump wherein veins stretch and flatten as the artery expands during contraction of the heart

Name the four branches (components) of the aorta in sequence as they extend from the heart. (V073)

- ascending aorta - arch of the aorta - thoracic aorta - abdominal aorta

What are the principal divisions of the (adult) skeletal system? (V009)

- axial skeleton - appendicular skeleton

What body structures comprise levers, fulcrums, efforts, and loads ? (V039)

A lever is a rigid structure that can move around a fixed point called a fulcrum . A lever is acted on at two different points by two different forces: the effort, which causes movement, and the load or resistance, which opposes movement. In the body, bones function as levers, and joints act as fulcrums for the levers. The effort is the force of muscular contraction, and the load is typically the body part moved.

Sutural bones

Also called Wormian bones This type of bone is classified by location rather than shape Small bones that are located in sutures between cranial bones Number varies greatly from person to person Apparently formed due to additional ossification centers in or near sutures Most commonly found in the lambdoid suture, but also seen in other sutures

What are the basic types of bones based primarily on shape? What are the attributes of each of the different shapes? Given an illustration of a bone, be able to recognize the type of bone based on shape. (V012-V018)

Basic types of bones (based primarily on shape): long short flat irregular sesamoid Sutural bones = in joint between skull bones

bipennate

Bipennate: Fascicles are arranged on both sides of centrally positioned tendons which extend nearly the entire length of the muscle. Example: Rectus femoris

What symptoms are associated with entrapment neuropathies? (V067)

Certain sites in the body are more likely to produce nerve entrapment because of anatomical vulnerability. Compression of blood vessels may also occur producing signs of poor peripheral circulation

circular

Circular (sphincter ("squeezer")): Fascicles in concentric circular arrangements form sphincter muscles that enclose an orifice. Example: orbicularis oculi

Irregular bones

Complex shapes that prevent grouping them into one of the previous categories Vary in amount of spongy and compact bone Examples: vertebrae, hip bones, calcaneus

Sesamoid bones

Develop in certain tendons that have considerable friction, tension, and physical stress Functions protect tendons from excessive wear and tear may change the direction of pull of a tendon, thereby improving the mechanical advantage at a joint Vary from person to person Not always completely ossified Examples: patellae

What are the three possible destinations of venous blood prior to entering the heart? (V074)

Drain blood from entire body & return it to right side of heart All venous blood drains to either superior or inferior vena cava or coronary sinus

What are the advantages to having circulatory routes to organs in parallel rather than in series? (V070)

Each organ receives its own supply of freshly oxygenated blood Lower total resistance

fusiform

Fusiform: fascicles nearly parallel to longitudinal axis of muscle; terminate in flat tendons; muscle tapers toward tendons, where diameter is less than at belly. Example: digastric muscle

Flat bones

Generally thin Typically composed of two nearly parallel plates of compact bone enclosing a layer of spongy bone Provide for protection Extensive areas for muscle attachment Examples: cranial bones, sternum, ribs, scapulae

Long bones

Greater length than width Consist of shaft and extremities (ends) Slightly curved for strength (curved bone absorbs stress of the body's weight at several different points, distributing it more evenly) Mostly compact bone in diaphyses Commonly spongy bone in epiphyses Examples: femur, tibia, humerus, ulna, radius

multipennate

Multipennate: Fascicles attach obliquely from many directions to several tendons, which in turn extend nearly the entire length of the muscle. Example: deltoid

Short bones

Nearly equal in length and width Consist of spongy bone tissue except at surface, which is thin layer of compact bone tissue Examples: carpal bones of wrist (except pisiform, which is a sesamoid bone)

Correlate the fascicular arrangement of muscles with the following: force of contraction, range of movement (range of contraction), speed (velocity) of contraction. (V032-V033)

Pennate muscles have considerable power over a short range of movement Parallel and fusiform muscles produce greater speed over a longer range of movement

What is the relationship between mechanical advantage or mechanical disadvantage of a lever, and the relative speeds of travel of the load and effort? (V056)

Since all parts of a lever sweep out the same arc in the same amount of time, and since work = force ͯ distance, the effort and the load exhibit the same amount of work If the effort travels further (and faster) than the load during their movement, the result is a lever having a mechanical advantage since less effort is needed to move the load If the load travels further (and faster) than the effort, the result is a mechanical disadvantage (but the load travels faster, so speed is gained)

What are the two main circulatory routes in the body? (V070)

Systemic and pulmonary

Given a drawing, illustration, or word description of a characteristic used to name muscles, state the applicable characteristic(s). (V026)

The most important characteristics include the direction in which the muscle fibers run, the size, shape, action, numbers of origins, and location of the muscle, and the sites of origin and insertion of the muscle: Pattern of the muscle's fascicles Size of the muscle Shape of the muscle Action of the muscle Number of origins Location of the muscle Sites of both origin and insertion of the muscle

What is the relationship between mechanical advantage and mechanical disadvantage, and distance between the fulcrum of the load and of the effort? (V046)

The positions of the effort, load, and fulcrum on the lever determine whether the lever operates at a mechanical advantage or disadvantage -when the load is close to the fulcrum and the effort is applied farther away, the lever operates at a mechanical advantage -when the effort is applied close to the fulcrum and the load is farther away, the lever operates at a mechanical disadvantage

triangular

Triangular (convergent): Fascicles spread over a broad area, and converge at a thick central tendon, giving muscle a triangular appearance. Example: pectoralis major

unipennate

Unipennate: Fascicles are short in relation to total muscle length, and are arranged on only one side of the tendon. Example: Extensor digitorum longus

Do most levers in the human body operate at a mechanical advantage, or do they operate at a mechanical disadvantage? (V054)

a mechanical disadvantage

What structural or anatomical situation is conducive to causing an entrapment neuropathy? (V064)

caused by physical compression or irritation of major nerve trunks and peripheral nerves, producing distant nerve pain symptoms Neck: Thoracic outlet syndrome Shoulder: Supraclavicular neuritis Elbow: Ulnar neuritis, Median neuritis, Radial neuritis Wrist: Carpal tunnel syndrome, Ulnar neuritis Leg: compartment syndrome

parallel

fascicles parallel to longitudinal axis of muscle; terminate at either end in flat tendons. Example: stylohyoid muscle, sartorius

sulcus

furrow along a bone surface that accommodates a blood vessel, nerve or tendon

condyle

large, rounded protuberance at the end of a bone

tuberosity

large, rounded, typically roughened projection

line (linea)

long, narrow ridge or border (less prominent than a crest)

fissure

narrow slit between adjacent parts of bones through which blood vessels and nerves pass

foramen

opening

What terms are used to describe the two points of attachment of most skeletal muscles? Which of these is normally the proximal attachment, and which is commonly the distal attachment? (V024)

origin and insertion the origin is proximal, the insertion is distal

epicondyle

projection above a condyle

crest

prominent ridge or elongated projection

third class lever

the effort is between the fulcrum and the load a third-class lever always produces a mechanical disadvantage because the effort is always closer to the fulcrum than the load the most common type of lever in the body example: the lever formed by the elbow joint, biceps brachii, and bones of the arm and forearm

spinous process

sharp, slender projection

tubercle

small, rounded projection

Given a drawing, illustration, or word description of a simple lever system in the body, identify the: class of lever, effort (force), fulcrum (axis), load (resistance). (V042, V047-V053)

the fulcrum is the elbow the load is the weight of the forearm plus the weight of the object the effort is the force of contraction of the biceps brachii first-class levers: The fulcrum is between the effort and the load, examples of which are scissors and the seesaw second-class levers: The load is between the fulcrum and the effort, the wheelbarrow being a well-known example third-class levers: The effort is between the fulcrum and the load, illustrated by the forceps

second class lever

the load is between the fulcrum and the effort a second-class lever always produces a mechanical advantage because the load is always closer to the fulcrum than the effort there are few second-class levers in the body example: the lever formed by the foot when standing on the toes

Apply Hilton's law to a joint wherein innervation of the associated muscle(s) and skin is known or supposed to be known. (V061)

the observation that a nerve that innervates a joint also tends to innervate the muscles that move the joint, and the skin that covers the attachments of those muscles This fact arises as a result of embryological development e.g. The musculocutaneous nerve supplies the elbow joint with pain and proprioception fibers. It also supplies biceps brachii and the brachialis which move the joint, as well as the forearm skin close to the insertion of each of those muscles

What is the most common type of lever in the body? (V053)

third class lever

Distinguish between a tubercle and a tuberosity. (V022)

tubercle is a small, rounded projection tuberosity is a large, rounded projection

trochanter

very large projection