BIOL273 Chapter Notes - Chapter 3: Endoplasmic Reticulum, Myocyte, Skeletal Muscle

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scarletbuffalo29

11 Sep 2016

School

University of Waterloo

Department

Biology

Course

BIOL273

Professor

Vivian Dayeh

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Document Summary

Origin of the muscle is the end of the muscle that is attached closer to the. The insertion of the muscle is the more mobile attachment/bone. If the centers of the connected bones are brought closer together when the muscle contracts, then the muscle is a flexor- the movement is called flexion. If the centers of the bones move away from each other when the muscle contracts, the movement is called extension. Most joins in the body have both flexor and extensor muscles, because a contracting muscle can pull a bone in one direction but can"t move it back- which is why both types of muscle are needed. Flexor-extensor pairs are called antagonistic muscle groups, because the exert opposite effects. Skeletal muscles are a collection of muscle cells, or muscle fibres. Each skeletal muscle fibre is a long cylindrical cell with up to several hundred nuclei near the surface of the fibre. They are the largest cells in the body.

Related Questions

Reflex Lab Procedures for Reflex Lab In this lab we will test muscle stretch reflexes and cutaneous reflexes. A partner is needed to be the subject for this lab. Purpose: To test and observe normal muscle stretch and cutaneous reflexes. Equipment: Reflex hammer, Background: In the most narrow sense, a reflex is an involuntary, unpremeditated response by the body to an external stimulus. Reflexes allow reaction to a stimulus more quickly than would be possible if conscious thought were involved. A reflex can be described as a stimulus-response cycle. Most reflexes involve the brainstem or the spinal cord and do not require interaction from higher brain centers. The muscle stretch reflexes are the simplest reflexes. They involve the sensory neuron synapsing directly upon the motor neuron. They are sometimes called monosynaptic reflexes. They are also called spinal reflexes because the reflexive action does not require input from the brain. The other reflexes we will be testing in this lab are the cutaneous reflexes. They are also called superficial reflexes because the receptors are in the superficial areas of the body. They are more complex and require the message to go up the spinal cord to the brain and then back down to elicit the response. These can be used to test for CNS injury. There are five components to a reflex; these components together are called the reflex arc. The components are as follows: sensory receptor â receives the stimulus and generates an impulse (is usually a nerve ending) afferent pathway â a neuron that carries the impulse from the receptor to a central integrating center integrating center âthis is where the afferent component connects to the efferent component- this is in the CNS. One or more synapses must occur here. Interneurons are not involved in stretch reflexes but are always found in all other types of reflexes. efferent pathway - a neuron that carries the impulse from the integrating center to an effector. effector -receives the impulse and responds. The effector may by skeletal muscle, smooth muscle, or glands.

Part I. Stretch reflexes.

First do muscle stretch reflexes which are also called deep tendon reflexes.

It is important the subject relax the muscle being tested. Tell the subject to let the muscle go limp.

Rate each response according to the following scale:

+4 very brisk, hyperactive, large movement at joint.

+3 brisker than average, medium movement at joint

+2 average, small movement at joint

+1 somewhat diminished, very small or no movement at joint

0 no response

A. Patellar (also called the knee jerk reflex) â activation of femoral nerve. The receptor is located in the quadriceps muscle, the effector is the quadriceps muscle. The nerve ending is responding to the stretch of the muscle caused by striking the tendon.

1. A subject is allowed to sit comfortably on a table with knees dangling over the edge.

2. Using a reflex hammer (or substitute as described above) strike the patellar tendon just below the kneecap.

3. Observe the action caused by the reflex.

4. Record your results using the graded scale above.

B. Biceps Reflex â activation of the musculocutaneous nerve

1. Rest subjectâs left forearm along your left forearm.

2. Subjectâs hand should rest in or near the bend of your elbow.

3. Press your left thumb on the subjectâs biceps tendon, apply a little pressure.

4. Strike your thumb with the reflex hammer, this will transfer the pressure to the biceps tendon.

5. Watch carefully for twitching of the biceps muscle. Usually, the forearm will not move.

6. Record your results using the graded scale above.

C. Triceps reflex â activation of the radial nerve.

This is a difficult reflex to observe, but give it a try.

1. The subject should have the arm relaxed and elbow bent.

2. Support the entire weight of the arm with your left hand.

3. Strike the triceps tendons, just above the elbow.

4. Watch carefully for twitching of the biceps muscle.

5. Record your results using the graded scale above.

Both B and C show up best on someone who doesnât have a lot of subcutaneous fat and who has good muscle definition.

D. Achilles reflex (also called ankle-jerk reflex) â activation of the poplitealnerve. The principle is similar to the knee-jerk reflex. Here the stretch receptors are located in the gastrocnemius muscle.

1. Have the subject take her/his shoes and socks off, exposing the Achilles tendon on the back of the ankle.

2. Strike the Achilles with the reflex hammer (or substitute) and observe the extension of the foot downward.

3. Record the results using the graded scale above.

Part II. Cutaneous reflexes

A. Plantar reflex

This reflex differs from the four muscle stretch reflexes. In this reflex, receptors are stimulated in the sole of the foot (cutaneous receptors). The reflex pathway travels up the leg to the integrating center. While in the integrating center, the reflex travels up the spinal cord through the pyramidal tracts, which are nerve pathways between the spinal cord and brain.

1. The subject needs to lie on his or her back, with shoes and socks off.

2. Using the end of the handle of the reflex hammer, trace a path along the lateral side from heel to the little toe to the big toe.

3. Observe for the flexion (toe curling) which is recorded as a normal plantar reflex.

4. If the toes curl, this is called a Negative Babinski response and is normal. If the toes flare, then an abnormal response is recorded and is called a Positive Babinski response and indicates CNS damage.

5. Record the results.

B. Ciliospinal reflex â This reflexive pathway is from the skin to the thoracic spinal cord, through the sympathetic trunk, then to the dilator pupillae muscle of the eye. This is another test of the CNS.

1. Pinch the back of the subjectâs neck,

2. Watch pupils for a response.

3. A normal response is dilation of the pupil.

4. Record your results.

[email protected]

Tue 9/19/2017 4:17 PM

To:

[email protected];

Here is the exam review for our next major lecture exam which will be on Monday. Notice that there are a few things missing, such as endochondral ossification. These will be added so just because it does not show up on this exam review doesn't mean you shouldn't study it. That being said, the details of each and every bone which I've gone over in lecture will be on the lab practical rather than the written lecture exam.

Anat 1, Exam 2. Spr 2016 LASC Name:____________________________________________________

1) A synarthrosis: a) is filled with synovial fluid. b) allow for a wide range of movement. c) includes the squamosal suture. d) is exemplified by the shoulder. e) all of the above.

2) Bursae: a) are located in the right atrium. b) are like elastomeric shock absorbers. c) are found in skeletal muscle fibers. d) form the sarcoplasmic reticulum. e) none of the above.

3) Irregular bones: a) can act like cams. b) can provide sites for muscle attachment. c) can protect soft-tissue organs. d) can act as levers. e) all of the above.

4) Condyles: a) are smooth articular surfaces. b) allow blood vessels to enter the bones. c) occur beneath the nail body after an injury. d) are produced by infected sebaceous glands. e) none of the above.

5) A head: a) is where you will find hyaline cartilage. b) is a smooth articular surface. c) is where a bone meshes with another bone. d) all of the above. e) none of the above.

6) Which of the following is the proper sequence of things following a bone fracture: a) hematoma, fibrous callus, bony callus, remodeling. b) hematoma, bony callus, fibrous callus, remodeling. c) hematoma, remodeling, fibrous callus, bony callus. d) hematoma, remodeling, bony callus, fibrous callus. e) fibrous callus, bony callus, remodeling, hematoma.

7) A diaphysis: a) contains yellow bone marrow. b) contain a lot of spongy bone tissue. c) occurs at the ends of long bones. d) all of the above. e) none of the above.

8) Short bones: a) protect underlying soft tissue organs. b) include the ribs. c) include the cranial bones of the skull. d) transfer mechanical forces. e) all of the above.

9) Fibrous joints: a) contain cruciate ligaments. b) include the pubic symphysis. c) are typically found in third class levering systems. d) include the lambdoid suture. e) all of the above.

10) Which of the following doesnât belong? a) tibiofibular joint. b) dentino-alveolar joint.
c) intervertebral disc. d) radioulnar articulation. e) cartilage.

11) Which of the following doesnât belong? a) atlanto-occipital joint. b) humero-ulnar joint. c) frontal suture d) acromio-humeral joint. e) tibiotarsal joint.

12) Hyaluronic acid: a) forms the extracellular matrix. b) is found in fibrous joints. c) keeps cartilage soft and pliable. d) is found in synostoses. e) none of the above.

13) First class levers: a) include the tibio-tarsal joint. b) have the effort between the fulcrum and the load. c) are like a teeter-totter. d) all of the above. e) none of the above.

14) Synchondroses: a) are typically synovial joints. b) allow for very limited movement. c) include sutures and gomphoses. d) are encased in synovial capsules. e) none of the above.

15) Parallel muscles: a) have long excursions. b) include the abdominal muscles. c) have excellent endurance. d) have low strength. e) all of the above.

16) Sphincteral muscles: a) enclose openings or passageways. b) are used when you talk.
c) surround the eyes. d) include the orbicularis oculi. e) all of the above.

17) Pennate muscle architecture: a) is typified by the pectoralis major. b) have high endurance.
c) generates high strength. d) has a longer excursion. e) all of the above

18) Endomysium: a) consists of dense fibrous connective tissue. b) surrounds each fasciculus.
c) surrounds bundles of muscle cells. d) all of the above. e) none of the above.

19) Cartilage: a) heals quickly if it is damaged. b) forms the lining of blood vessels. c) is found on the articular surfaces of bones. d) is a type of epithelial tissue. e) none of the above.

20) A tuberosity: a) is a hollow opening. b) is a shallow smooth articular surface. c) is a raised area that adjoins a condyle. d) is a larger outwardly curved articular surface. e) is a raised, rough-textured area.

21) Which of these doesnât belong? a) tuberosity b) trochanter c) condyle d) tubercle e) lunula

22) Epimysium: a) wraps around the entire muscle. b) is made of dense fibrous connective tissue. c) is continuous with tendons. d) all of the above. e) none of the above.

23) Which of the following is more likely to be an insertion rather than an origin? a) ulna.
b) cervical vertebra. c) thoracic vertebra. d) rib. e) Ischium.

24) Which of the following is more likely to be an origin rather than an insertion? a) clavicle.
b) tibia. c) radius. d) ulna. e) metatarsal.

25) Myofibrils: a) are composed of many muscle fibers. b) are composed of many muscle cells.
c) are composed of many sarcomeres. d) form the endomysium. e) all of the above.

26) Myosin: a) helps keep muscle cells from overstretching. b) is a protein. c) joins thin filaments together. d) forms part of the z-disc. e) all of the above.

27) Sarcolemma: a) surrounds the entire muscle organ. b) surrounds the endomysium.
c) is the cell membrane of a muscle fiber. d) surrounds the epimysium. e) none of the above.

28) Thin filaments: a) are made of titin. b) are pulled on by the thick filaments during contraction.
c) create the molecular âpower-strokeâ. d) all of the above. e) none of the above.

29) A second class lever: a) is like a wheel barrow. b) is like a teeter-totter. c) describes the humeroulnar joint. d) describes the atlanto-occipital joint. e) none of the above.

30) A sarcomere: a) is the basic unit of muscle function. b) is made mostly of proteins. c) shortens during a contraction. d) delivers an âall or noneâ response. e) all of the above.

31) Fast glycolytic fibers: a) have excellent endurance. b) deliver lots of power.
c) are more reddish in color than oxidative fibers. d) none of the above. e) all of the above.

32) Which of the following doesnât belong? a) Vastus lateralus. b) Vastus intermedius. c) Vastus medialis. d) Rectus Femoris. e) Gluteus minimus.

33) Which of the following doesnât belong? a) Teres major. b) Teres minor. c) subscapularis.
d) infraspinatus. e) supraspinatus.

34) Tendon sheaths: a) are filled with synovial fluid. b) can be likened to brake and shifter cable sheathing on a bike. c) are found around the carpal bones. d) really make life unpleasant if they get inflamed. e) all of the above.

35) Epithelial tissues: a) function in movement. b) conduct electrical impulses. c) form a structure for attachment of other organs. d) form barriers and walls. e) all of the above.

36) Elastic connective tissue: a) is found in bone. b) lines the inside of the trachea. c)Is found in small blood vessels like capillaries. d) is found in large arteries. e) all of the above.

37) Cartilage: a) heals quickly if it is damaged. b) forms the lining of blood vessels. c) is found on the articular surfaces of bones. d) is a type of epithelial tissue. e) none of the above.

38) Dense regular connective tissue: a) is poorly vascularized. b) heals slowly if at all. c) forms tendons and ligaments. d) can look a lot like smooth muscle under the microscope. e) all of the above.

39) Transitional epithelium: a) lines the urinary bladder. b) lines the blood vessels. c) contains cilia. d) joins the epidermis to the dermis. e) none of the above.

40) Skeletal muscle: a) responds to conscious thought. b) is found in the heart. c) is found in the walls of blood vessels and the GI tract. d) is composed of very small cells. e) all of the above.

For the following matching questions, each choice is used only once.

41) Fibroblast a) maintains bone tissue
42) Mast Cell b) secretes mucus
43) Chondrocyte c) responsible for inflammation response
44) Osteocyte d) makes collagen fibers
45) Goblet Cell e) maintains cartilage

For the following true-false questions, mark âAâ for true and âBâ for false.

46) Simple cuboidal epithelium is lines the trachea and Fallopian tubes/oviducts.
47) Elastic cartilage joins the ribs to the sternum.
48) An insertion is the more movable point of muscle attachment.
49) Tendons connect muscle to muscle or bone to bone.
50) Ligaments connect muscle to bone.
51) Transverse tubules allow nutrients to be dispersed throughout very large muscle cells.
52) Muscle twitch occurs when only a few muscle cells in the entire muscle are fully contracted.
53) Slow oxidative fibers have poor strength but excellent endurance.
54) Muscles can lengthen under their own power as well as contract.
55) Pottâs fracture is typical of skateboarders.
56) An incomplete fracture is a complete break through the entire bone.
57) Tetanus is the recruitment of additional fibers during muscle contraction.
58) Menisci are like elastomeric shock absorbers.
59) Diarthrotic joints allow for little to no movement.
60) A belly is the contractile portion of a muscle.
61) Synergistic muscles work with each other.
62) Muscle tissue, like your lab instructorâs evil twin before his morning coffee, is irritable.

redbutterfly464

1. Consider the following eight statements about vertebrae. Which four of the following eight statements are TRUE? Choose all four correct answers.

(a) In Actinopterygii, Chondrichthyes, and some Amphibia (and one unusual taxon of Lepidosauria), the vertebrae have centra which surround the notochord.

(b) Some vertebrae have processes such as spines that function as sites for muscle attachment.

(d) In tetrapods, the vertebrae have processes called zygapophyses that function as specialized sites for articulation with the ribs.

(e) Vertebrae arise from sclerotome epimere mesoderm.

(f) All extant vertebrate taxa have vertebrae.

(g) Some vertebrae have hemal arches which protect blood vessels (such as the dorsal aorta).

(h) Vertebrae have neural arches which protect the notochord.

2. While walking through the halls of the Biosciences building, you find a single vertebra lying on the floor. You notice that it does not have zygapophyses. It has an amphicoelous centrum, and it has both a neural arch and a hemal arch. This vertebra is completely ossified. Identify to which vertebrate taxon this vertebra belongs, and to which region of the vertebral column.

(a) caudal region - Petromyzontida

(b) thoracic region - Aves

(d) trunk region - Actinopterygii

(e) caudal region - Actinopterygii

(f) caudal region - Amphibia

(g) caudal region - Chondrichthyes

3. You are doing a study on the diet of polar bears. While examining the scat (droppings) of a large polar bear, you find a single vertebrae. You need to identify this vertebra to determine what this polar bear has been eating. Polar bears are known to eat mammals, birds, and some fish (Actinopterygii). This vertebra has a heterocoelous centra and it has no articulation sites for ribs. It also has an odontoid process. To which of these three vertebrate taxa, and to which region of the vertebral column does this vertebra belong?

(a) synsacral region - Aves

(b) cervical region - Mammalia

(d) cervical region - Aves

(e) caudal region - Actinopterygii

(f) thoracic region - Mammalia

4. Which four of the following eight statements about the skeleton are TRUE? (Choose all four correct options.)

(a) Bone is a tissue that is able to withstand large tensile forces but not large compressive forces.

(b) An important role of the vertebral column in actinopterygii and chondrichthyes is to support the body weight.

(c) in amniotes, the ribs consist of two parts, a costal rib (which articulates with a thoracic vertebra) and a sternal rib (which articulates with the sternum). The mobile joints between the costal and sternal rib, as well as between the costal rib and the vertebra and between the sternal rib and the sternum, make the ribcage flexible such that it can expand during breathing.

(d) A vertebral column with procoelous centra would have a greater range of mobility than a vertebral column with acoelous centra.

(e) In all extant vertebrate taxa, the vertebral column provides axial structural support, as well as support for locomotion.

(f) In many mammals, ligaments and muscles attaching to the neural spines of vertebrae help to stabilize the vertebral column and pull it into a stable arch, which helps to efficiently bridge the body weight to the legs.

(g) In tetrapods, the pectoral girdle is firmly fused to the vertebral column to allow for efficient transfer of locomotive forces from the forelimbs to the axial skeleton.

(h) In chondrichthyes, actinopterygii, sarcopterygii, and some tetrapods, the vertebral column acts as a firm but flexible rod on which muscles pull to produce lateral undulations of the body for locomotion.

5. Consider the following eight statements about the form and function of the appendicular skeleton. Which four of the following eight statements are TRUE? (Choose all four correct options.)

(a) In sharks (Chondrichthyes), the pectoral and pelvic fins are mainly used for propulsion - to propel the body forward through the water.

(b) The tips of fins are supported by fin rays, thin rods which support a webbing of skin (and sometimes also connective tissue) - this increases the surface area of the fin

(c) The fleshy fins of sarcopterygii are not very maneuverable, and are used only to stabilize the body by preventing roll, pitch, and yaw when swimming rapidly.

(d) In both actinopterygii and chondrichthyes, the pectoral girdle attaches directly to the back of the skull while the pelvic girdle is embedded in the muscle of the body wall.

(e) In both sharks (Chondrichthyes) and actinopterygii, the pectoral and pelvic fins provide stability while swimming by preventing roll, pitch, and yaw.

(f) In male chondrichthyes, the pelvic fins have special extensions called claspers that are used to transfer sperm to females during copulation for internal fertilization.

(g) Petromyzontida and myxinoidea have paired pectoral and pelvic fins that are used to provide stability while swimming, as well as for steering.

(h) The main functions of girdles are to provide attachment sites for the muscles of the appendages (paired fins or limbs) and to stabilize the appendages.

6. Consider the following statements related to the appendicular skeleton and terrestrial locomotion of tetrapods. Which three of the following six statements are CORRECT? (Choose all three correct options.)

(a) In tetrapods with erect limb posture, the limbs are positioned directly under the body, while in tetrapods with sprawled limb posture, the limbs are positioned to the sides of the body.

(b) In terrestrial tetrapods, the distal ends of the humerus and femur are rotated such that the digits are oriented in line with the direction of travel, increasing both tractive and propulsive forces during terrestrial locomotion.

(c) Tetrapods with digitigrade foot posture have relatively longer limbs than tetrapods with plantigrade foot posture, such that they have a greater stride length.

(d) When terrestrial tetrapods are walking or running, the recovery stroke of the limbs involves the limb touching the ground while the propulsive stroke of the limbs involves the limb being lifted and moving from posterior to anterior.

(e) In tetrapods with sprawled limb posture, the dorsal elements of the pectoral girdle (such as the scapula) are much larger than the ventral elements of the pectoral girdle (such as the clavicle and corocoid).

(f) When walking or running, tetrapods with erect limb posture use an overarm swing for the recovery stroke, which is relatively slow.

7. You are walking along the beach and find a skeleton in the sand. You notice that the pelvic girdle is not fused to the vertebral column while the pectoral girdle is fused to the skull. The distal ends of the appendages have fin rays. It appears that all muscles controlling the appendages were located within the body wall, not within the appendages. To which vertebrate taxon does this skeleton belong?

(a) Sarcopterygii

(b) Lepidosauria

(d) Amphibia

(e) Actinopterygii

(f) Petromyzontida

8. Your neighbour finds a skeleton while cleaning out the pond in her backyard, and she asks you to identify it. You notice that the vertebrae have zygapophyses and that the centra of the vertebrae are procoelous. The ribs are quite short, and articulate with the vertebrae but not with the sternum. The pelvic and pectoral girdles appear robust and highly ossified, and the pectoral girdle has enlarged ventral elements but relatively small dorsal elements. The appendages each have five digits. Identify this skeleton for your neighbour, and describe to her as much as you can about its style of locomotion, based on this information about its axial and appendicular skeleton. (Choose all three correct options.)

(a) This skeleton is most likely from an amphibian.

(b) This skeleton is most likely from a sarcopterygian.

(d) This animal most likely had sprawled limb posture.

(e) This animal most likely could not support its own body weight using its appendages, and so would not have been capable of terrestrial locomotion.

(f) This animal probably walked with lateral undulations of the body, using the feet as pivot points.

(g) This animal most likely walked with a recovery stroke that used an energetically efficient pendulum-like swing.

(h) This skeleton is most likely from a crocodilian (Archosauria).

BIOL273 Chapter Notes - Chapter 3: Endoplasmic Reticulum, Myocyte, Skeletal Muscle

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