Quizzes for  Exam 3 A&P I

These questions are to help you quiz yourself. To see my answers, select the area underneath the question using your mouse. (click and drag)  Don't print this out, or the answers will be visible as well!
 

I will be working on these periodically, but I wanted you to have this for review right away:

Muscle contraction review:
The neurotransmitter Acetylcholine is released from the end bulb of the axon of a motor nerve.
The neurotransmitter crosses the synaptic cleft and binds with receptors on the motor end plate of the muscle fiber.
This binding opens sodium ion channels in the sarcolemma.
The inflow of ions causes depolarization of the membrane and the propagation of a muscle action potential along the membrane.
This flow travels down the t-tubules and causes the sarcoplasmic reticulum to release calcium ions into the sarcoplasm.
This binds with the protein troponin which changes shape and pulls on the protein tropomyosin and exposes the myosin binding sites on the actin.
Myosin heads, which are charged with ATP, grab onto the actin and perform a power stroke, bringing the Z-lines closer together, contracting the muscle.
Myosin releases the actin to grab another molecule of ATP.

Chapter 7

Classify the following bones according to their shape:      

The humerus - a long bone
A vertebra  - an irregular bone
The patella - a sesamoid bone
A carpal bone - a short bone
A phalanx -  also a long bone
The temporal bone -  a flat bone

Osteoblast, osteoclast, osteoprogenitor cell, osteocyte:
Which cell breaks bone down?     The osteoclast
Which is a mature bone cell?     The osteocyte – it is found in bone surrounded by calcified matrix.
Which is an immature bone cell that lays down matrix and builds new bone?   The osteoblast
Which cell comes from a different source than the others?   The osteoclast – i

What protein is part of the organic matrix of bone and why is it important?  Collagen – it provides the bone with tensile strength; makes it more flexible and less brittle than the bone would be without it.
What two minerals make up most of bone? Calcium and phosphorus (phosphate)
What structure is present in compact bone but missing in spongy bone? The central canal – spongy bone is surrounded by red bone marrow and blood, so it doesn’t need the central canal.
How are most bones formed?  By endochondral ossification – they are formed within a cartilage model.
What is a fontanel and what does it do?  This is the “soft spot” in a baby’s skull. These bones are formed by intramembranous ossification, and have not formed in these areas. The fontanels allow the baby’s head to change shape to fit through the birth canal.
Little Johnny is short for his age. His parents want his doctor to give Johnny shots of growth hormone. What is the first thing the doctor will do before giving the hormone?  He should x-ray Johnny’s long bones to be sure that the epiphyseal plate is still present and capable of growing.
True or false: bone is a static (unchanging) tissue.    False!  Bone is constantly being broken down and built up, and is capable of responding to stress. This process is called remodeling.
Your blood levels of calcium are too low. What will your body do to correct this?  It will produce parathyroid hormone, which stimulates the activity of osteoclasts. Bone is broken down, and calcium is released in the blood stream. PTH also causes the kidneys to reabsorb more calcium instead of losing it in the urine.
How do the sex hormones (estrogen and testosterone) affect bones?
At puberty, the initial spurt of sex hormones causes bones to lengthen. When levels of these hormones reach higher levels, they cause the epiphyseal plates to close and long bones to stop growing. When we get older, decreasing levels of these hormones cause more bone to be broken down than built up, and our bones become less dense and therefore become more fragile. This is called osteoporosis.
For each of the following bones, tell whether it is a part of the axial or appendicular skeleton.
Frontal bone -   axial
Hyoid bone -  axial
Clavicle -  appendicular
Sternum -  axial
Scapula -   appendicular
Ischium -  appendicular
Coccyx  -  axial
Humerus  -  appendicular
Rib - axial

r vertebrochondral rib

Along what suture do you tend to find sutural (Wormian) bones?   The lambdoidal
The annulus fibrosis of  an intervertebral disc is made up of what material?  Fibrocartilage
When a baby can hold up its head, what secondary spinal curvature develops?  The cervical curvature
What kind of rib would the fifth rib be? A true or vertebrosternal rib
What kind of rib would the twelfth rib be? A floating rib or vertebral rib.
What kind of rib would the ninth rib be ?  A false or vertebrochondral rib.

What are the 5  functions of bones? Support, protection, movement, storage and blood cell production or hematopoiesis.
In what bone would you find the sella turcica? In the sphenoid bone - it protects the pituitary gland.
In what bone would you find the cribriform plate?   In the ethmoid bone - sensory fibers pass from your nasal cavity into your cranial cavity through the holes found here.
What is unusual about the hyoid bone? It is the only bone of the body that does not articulate with another bone.
What is the structure of an intervertebral disc? It has an outer ring of fibrocartilage called the annulus fibrosa, and an inner core called the nucleus pulposa.

Chapter 8
Identify the structural and functional classification of the following types of joints:

The knee - synovial joint, diarthrosis
Syndesmosis - fibrous joint, amphiarthrosis
Suture -fibrous joint, a synarthrosis - immovable joint
Synchondrosis - cartilaginous joint, synarthrosis
 

For the following diarthroses, name the type of joint each represents:

The hip-  ball and socket
The articulation of the radius and the carpals-  condyloid joint
The articulation of the humerus and ulna - hinge joint
The proximal articulation of the radius and ulna - Pivot joint
The articulation of the trapezium and the metacarpal of the thumb- saddle joint
The articulations of the carpals with one another - gliding joints
The shoulder  -  ball and socket
The articulation of the metacarpals and phalanges - condyloid joint
The articulations between the phalanges - hinge joints
The articulation of the atlas and axis - pivot joint

A movement that brings a body part closer to the midline of the body is called: adduction
When a movement decreases the angle between two parts it is called:  flexion
When the hand is turned so that the palm faces up it is called: supination
When a body part turns around its long axis the movement is called: rotation
When you pull your shoulders back it is called: retraction
When you flex your foot toward the sole of the foot it is called:  plantar flexion
When you turn the soles of your feet toward each other the movement is: inversion

What is the weakest part of the shoulder joint ? The inferior aspect
Which is deeper, the acetabulum or the glenoid cavity? The acetabulum
True or false: The ligamentum capitis helps hold the head of the femur into the hip socket. False, it is merely a structure for the passage of nerves and blood vessels.
What structure strengthens the medial side of the knee joint ? The tibial collateral ligament.

Chapter 9 
Fill in the table:
 

Type of Muscle	Voluntary?	Striations?	Other characteristics ?
Skeletal	Voluntary	Striated	The muscle that attaches to bones; long, multinucleate cells
Cardiac	Involuntary	Striated	Autorhythmicity, gap junctions, branched cells
Smooth	Involuntary	Nonstriated	Some autorhythmicity, some gap junctions, cells spindle-shaped

What type of tissue makes up a tendon? Dense regular connective tissue.
What is a motor unit? A single motor neuron and all the muscle fibers that it innervates (controls).
 What neurotransmitter is  always released  at the synapse of a motor neuron and skeletal muscle? acetylcholine (ACh)
What is a muscle fiber? A single muscle cell.
What protein makes up the thick filaments? Myosin
What three proteins are found in the thin filaments? Actin, along with troponin and tropomyosin
Rigor mortis is due to the fact we run out of what after we die?  ATP - this is what makes the myosin heads of the skeletal muscles release the actin molecules.
What is calsequestrin and what does it do? This is a molecule found in the sarcoplasmic reticulum. It binds Ca++ so that the osmotic pressure inside the sarcoplasmic reticulum doesn't get too great and draw in all the water in the cell.
How do muscles maintain homeostasis of body temperature? Where is the control center for this?
Every time a muscle contracts it produces heat as a waste product, but does help contribute to keeping the body warm. If the body gets too cold, the hypothalamus can cause shivering - rhythmic muscle contractions - which can increase the body's heat production by several hundred percent.
What does it mean that muscle contraction is all-or-none? Each individual muscle cell or fiber either contracts fully when stimulated, or it doesn't contract at all. How much a whole muscle contracts depends on the number of motor units activated, but the cells in each motor unit contract fully.
Is glycolysis an aerobic or anaerobic process? If there is no available oxygen, what is its end product?
Anaerobic all by itself. When oxygen is low, the pyruvic acid is turned into lactic acid.
What are the two sources of oxygen available to muscle? Oxygen in the blood in the capillaries, and the oxygen stored in myoglobin within the muscle cells.
What is tetanus, and why does it occur? Tetanus is a smooth, sustained muscle contraction ( like the ones that occur in your arm when you salute the flag - we are not talking about the disease that you get shots for here.) When the muscle cells are stimulated frequently enough, the twitch contractions sum or add together to form a  sustained or prolonged muscle contraction.
I push against the wall, harder and harder, but it won't budge. Because of that, my muscles have not changed in length. What type of muscle contraction have I been using?  Isometric contraction
How does cardiac muscle differ from skeletal muscle?  Cardiac muscle cells have less sarcoplasmic reticulum and only one t-tubule per sarcomere. They get a lot of their calcium for contraction from outside the cell - from the fluid in the t-tubules.
What structures are present in cardiac muscle that are not found in skeletal muscle? Intercalated discs, which contain gap junctions that connect the cytoplasm of these cells, and desmosomes that hold the cells together during contractions.
A group of smooth muscle cells that are connected by gap junctions and all contract together are called:
 single-unit smooth muscle.
How does smooth muscle differ from skeletal muscle? It still has actin and myosin, but also has intermediate fibers which transfer the tension from the actin and myosin to the dense bodies when the cell contracts. It does not have troponin and tropomyosin; instead a substance called calmodulin controls contractions by activating an enzyme that puts the ATP on the myosin heads. It responds to Ca++, like troponin, but all the Ca++ comes into smooth muscle from the interstitial fluid outside the cell; smooth muscle cells have no t-tubules.
The deltoid muscle attaches to the clavicle and scapula at one end and to the humerus at the other. Which attachment would be its insertion? The attachment to the humerus - the more movable structure.
What would you call a muscle that has an action which is directly opposite to a prime mover?  an antagonist
What would you call a muscle that has an action which assists a prime mover?   A synergist