Lecture Exam 2

Question 1

What is a joint?

Answer 1

• When two bones meet
• Bone to bone, bone to cartilage, teeth in socket
• The structure of joints allows for resistance to crushing tearing and other forces

Question 2

List the joints by functional classification (immoveable, slightly moveable, freely moveable)

Answer 2

Synarthroses - Immovable joints
Amphiarthroses - Slightly movable joints
Diarthroses - Freely movable joints

Question 3

Name the joints based on structural classification and examples.

Answer 3

Fibrous
- Joins bones via collagen fibers
- Sutures (immobile), syndesmosis (slight mobility/ no mobility), gomphosis (immobile)

Cartilaginous
- Adjoining bones via cartilage
- Synchondrosis (hyaline, immobile) and symphysis (fibrocartilage, slightly mobile)

Synovial
- Bones separated by joint cavity, have articular cartilage, enclosed within articular capsule
- Plane, hinge, pivot, condylar, saddle, ball and socket are all freely movable

Question 4

What are the three types of fibrous joints? What is the structure like? Give examples.

Answer 4

Suture
- Joint held together by short interconnecting fibers. Only in skull
Syndesmosis
- Joint held together by ligament
Gomphosis
- Peg in socket fibrous joint

Question 5

What are two main types of cartilaginous joints? What is the structure like? Give examples.

Answer 5

Synchondroses
- Bones jointed by cartilage (ribs and sternal connection)
Symphyses
- Bones united by fibrocartilage (spine and pubic symphysis)

Question 6

What is abduct, adduct, extend, flexion? What type of movement is involved in jumping jacks and bending the knee?

Answer 6

Abduct - To move away from medial plane
Adduct - To move towards medial plane
Extension - Increases the angle between two parts of the body
Flexion - Decreases the angle between two parts of the body

Jumping jacks - Involve abduction as arms and legs go out to the sides. Extension is also involved as limbs are straight. When bringing arms and legs back to your side adduction and flexion are involved

Question 7

What is the structure of the synovial joints? What is their function?

Answer 7

• Synovial joints are composed of a joint cavity, articular capsule, articular cartilage, two or more bones, synovial fluid, blood vessels and nerves
• Synovial joints allow for diarthrotic movement.

Question 8

What are the six types of synovial joints discussed in lecture?

Answer 8

Planar - Intertarsal joints (short gliding)
Hinge - Knee (single plane movement)
Pivot - Atlantoaxial (allows for rotation)
Condyloid - metacarpal-phalangeal
Saddle - First metacarpal (opposition)
Ball and socket - Shoulder

Question 9

What are two compound synovial joints?

Answer 9

Elbow joint
- Includes humerus, radius, and ulna
Knee joint
- Includes femur, tibia, and fibula

Question 10

List three factors that influence synovial joints stability (in order of importance of role)

Answer 10

Muscle tone
- Most important for joint stability. Keeps tension on muscle tendons. Proprioceptors (positional awareness)
Ligaments
- More ligaments = Stronger joint. stretching can lead to deterioration
Articular surfaces
- Rarely play major role in joint stability. Elbow, knee, and hip provide stability. Shapes determine possible movements

Question 11

What are the key features of the shoulder joint?

Answer 11

Shoulder
- Most freely moving joint, lacks stability
- Glenoid labrum is a rim of fibrocartilage that deepens glenoid cavity
- Many ligaments play important role
- Biceps brachii tendon is the most important stabilizer
- Rotator cuff is composed of Subscapular is, supraspinatus, infraspinatus, and teres minor which help stabilize the shoulder while maintaining a wide range of motion
- Easily dislocated because of how mobile the joint is

Question 12

What are key features of the knee joint?

Answer 12

• Tibiofemoral join us the largest and most complex joint
• Primarily acts as hinge joints
• Composed of tibial and fibular collateral ligaments, medial and lateral menisci, posterior and anterior cruciate ligament, patellar ligament, and oblique popliteal ligament
• Menisci evenly distribute compressive load and guide condyles during flexion
• Cruciate ligaments stabilize forward and backward movement of knee

Question 13

What is Arthritis? What are the causes?

Answer 13

Osteoarthritis - When the two ends of bones rub together
- Caused by wear and tear of cartilage over time
Rheumatoid Arthritis - Joint is always swollen and inflamed and bone erodes
- Autoimmune disorder where immune system attacks synovial joint

Question 14

What is the integumentary system? What are the functions?

Answer 14

Integumenary system is the skin and its appendages

• Protect against heat, infection, cushions, chemicals, abraion, UV rays
• Aid in water retention
• Helps regulate body heat via insulation
• Sensory receptors

Question 15

What are the characteristics of epidermis? Layers? Cell types?

Answer 15

Epidermis is the the superficial thick layer of epithelium

• The top layers of cells composed of strata corneum, lucidum, granulosum, spinousum, basale

Cell types:
- Keratinocytes
- Abundant, produce keratin (tough protein) that gives epidermis protective properties
- Langerhans cells
- Macrophages
- Tactile cells
- Few, touch receptors
- Melanocytes
- Spider shaped cells, melanin phagocytized by Keratinocytes, protects against UV (melanoma)

Question 16

What are the characteristics of dermis? What structures are in dermis?

Answer 16

Dermis:
- Connective tissue
- Highly vascularized and innervated
- Thermoregulation

Structures:
- Hair bulb, sebaceous gland, eccrine gland, apocrine gland, arrector pili muscle, nerves, blood vessels

Question 17

What are the two layers found in dermis? What are they composed of?

Answer 17

Papillary layer
- 20% of the layer
- Areolar CT, dermal papillae, causes friction ridges (finger prints)
Reticular layer
- 80%
- Network of collagen and elastin fibers
- Forms lines of cleavage
- Stretch marks = torn collagen
- Thick layer of dense IR CT
- Very vascular and innervated

Question 18

What is hypodermis? Is it a part of the integument?

Answer 18

• Layer decomposed mostly of fat (superficial fascia)
• Anchors skin to underlying muscle or bone
• Very vascular (where injections occur)
• Allow skin sliding
• Good insulator
• Not a part of integument but is tied very closely due to its structure and function

Question 19

What factors can affect skin color?

Answer 19

Melanocytes influence skin color along with keratinocytes. Sun can also cause cells in the stratum corneum to darken (tanning)

Question 20

What are the appendages of the skin and what layer are they found in? Know the characteristics and structures associated.

Answer 20

• Appendages derived from epidermis but extend into dermis
• Hair and hair follicle
• Sebaceous glands
• Sweat gland
• Nails - Composed of lunule, eponychium, body root, and free edge

Question 21

What is the structure of hair?

Answer 21

• Bulb
  
  • Matrix - dividing cells
  • Dermal papilla - vasc. provides nutrients
• Root
• Shaft
• Medulla, cortex, cuticle
• Follicle - Tube for hair
  
  • Epithelial root sheath
  • Connective tissue root sheath
• Arrector pili muscle

Question 22

What are cutaneous glands?

Answer 22

Two types of sweat glands
Merocrine - true sweat, watery
Apocrine - axillary, anal, areolar, genital, strong odor and associated with hair follicles

Sebaceous - associated with hair follicle
Ceruminous - auditory canal
Mammary - modified apocrine

Question 23

What are the differences between 1st, 2nd, 3rd degree burns? Why can serious burns be life threatening?

Answer 23

1st - Only harms epidermal layer (blister)
2nd - Harms epidermis and top layer of dermis and needs time to regenerate
3rd - Destroys epidermis and dermis and may extend into underlying tissue. Often needs skin graft

Serious burns can lead to fluid loss, infection, and eschar (burned dead tissue)

Question 24

What are the types of carcinomas? What is the ABCDE rule?

Answer 24

Basal cell - Least manignant. in stratum basale Proliferate and invade dermis. can be surgically removed

Squamous cell - Arise from keratinocytes of stratum spinosum. scaly and irregular. Can be removed surgically

Melanoma - cancer of melanocytes. larger than 6 mm = likely death, resistant to chemo and immunotherapy

Asymmetry, border irregularity, color, diameter (6mm), elevation

Question 25

What are three types of muscle? Classify according to histology and function. Which muscle type is multinucleated?

Answer 25

Smooth - Nonstriated, involuntary, spindle shaped Cardiac - Striated, involuntary, branched, cardiocytes -**intercalated disks** Skeletal - Striated, voluntary, myofibers

Question 26

Compare and contrast smooth muscle and cardiac muscle to skeletal muscle.

Answer 26

- Smooth muscle and cardiac muscle contraction involuntarily - Cardiac muscle is branching - Skeletal muscle moves voluntarily - Both cardiac muscle and skeletal muscle are multinucleated

Question 27

Label a diagram of whole muscle(as well as a diagram of a single fiber

Answer 27

Question 28

Draw and label a sarcomere and associated structures. Which bands change length with contraction? Why do regions shorten while others do not?

Answer 28

Bands that contract: - I band - H band Non contracting components: - M line - Z disc - A band

Question 29

What is the function of transverse tubules, sarcoplasmic reticulum, terminal cisternae, and triads?

Answer 29

- Transverse tubules are invaginations of the sarcoplasmic membrane which allows rapid transition of electrical currents - The sarcoplasmic reticulum is the calcium stores of the muscle - Terminal cisternae are the gates that respond to an electric signal and release the calcium. They are found on either side of the T tubules - The triad is the union of the t-tubule and two terminal cisternae

Question 30

Describe the events of muscle contraction? How are actin, myosin, tropomyosin and troponin involved?

Answer 30

1. Cross bridge is resting (ATP) - Troponin does not have Ca, tropomyosin is covering attachment site of actin 2. Electric signal causes release of Ca from Sarcoplasmic Reticulum (SR) 3. Calcium binds to Troponin which causes tropomyosin to move and unblock the actin binding sites - myosin head will then attach to actin (uses energy from ATP->ADP+Pi) 4. Myosin head does power stroke(pull) using the energy from hydrolysis of ATP into ADP+Pi and releases ADP+Pi 5. Once ATP binds to myosin head the crossbridge is broken and the cycle can start once a new ATP binds

Question 31

What are three types of skeletal muscle fibers and their characteristics? list histological appearance of the different types of fibers and examples.

Answer 31

Slow Oxidative(white): - High myoglobin content - Low glycogen - Small fiber diameter - Used to stand Intermediate Oxidative(pink): - High myoglobin content - Low glycogen - Intermediate fiber diameter - Used while jogging Fast glycolytic(red): - Low myoglobin content - High glycogen - Thick fiber diameter - Used while sprinting

Question 32

What are nerves? What are dendrites? What is the axon hillock?

Answer 32

- Nerves are the communication routes for contraction of a muscle - Dendrited are the receivers of the electrical signal of a nerve cell - The axon hillock is where the signal is propagated if the action potential is met. Once the action potential is met rapid depolarization down the axon occurs

Question 33

How does a neuron rapidly transmit a signal? How can a neuron cross the NMJ to pass the electrical signal form a neuron to a muscle?

Answer 33

- Rapid polarization of the axon is caused by the negative membrane charge changing rapidly as the Na enters. Once the signal has passed the membrane will become negative as K enters membrane again and Na leaves - The electrical signal reaches the end of the neuromuscular junction and is converted into a chemical signal as acetylcholine is released into the synaptic cleft which can then bind to muscle causing a contraction. - (Signal goes from electric to chemical. Then when chemical signal binds to receptors it is converted back into electrical signal.)

Question 34

How does innervation of muscles work? Label a neuron and know its function. What is action potential with respect to muscle?

Answer 34

- A muscle fiber is innervated by a single neuron. But a single neuron can innervate many fibers(cells). - Recruitment of other motor units is necessary for strong contraction

Question 35

What is the neuromuscular junction? What is a motor unit? What makes contractions occur?

Answer 35

- Neuromuscular junction is the end of a neuron, the synaptic cleft, and the sarcolemma of a muscle fiber - A motor unit is a neuron that innervates many muscle fibers (cells) and the muscle it innervates

Question 36

Define origin and insertion of a muscle. What is an aponeurosis

Answer 36

- Origin is the least movable part of a muscle - Insertion is the most movable part - Belly is the fleshy bit between origin and insertion - Aponeurosis is a fibrous tissue (like tendon)that connects the muscle to what they move by attaching to various structures.

Question 37

What are the classes of levers?

Answer 37

Class I - Load is on one side, fulcrum is in the middle, effort is opposite to the load (scale) Class II - Load is between fulcrum and effort (calf raise) Class III - Effort is applied between the fulcrum and the load (Bicep curl)

Question 38

What is a prime mover, antagonist, synergist, fixation muscle?

Answer 38

- Prime mover is the main muscle responsible for causing a movement - Antagonist is the opposite of a prime mover - Synergist helps a prime mover carry out movement - Fixator stabilizes a prime mover so it can function

Question 39

Label the muscles by type and name

Answer 39

a. Orbicularis Oris - Circular b. Pectoralis major - Convergent c. Sartorius - Parallel d. Extensor digitorum longus - Unipennate e. Deltoid - Multipennate f. Biceps brachii - Fusiform g. Rectus femoris - Bipennate

Question 40

What are the arrangements of fascicles in muscles

Answer 40

Parallel - Strap like (Sartorius) Fusiform - Spindle (biceps brachii) Convergent - Fan shaped (pectoralis major) Pennate - Feather shaped - Unipennate (flexor pollicis longus) - bipennate (Rectus femoris) - multipennate (deltoid) Circular - Rings (orbicularis Oris)

Question 41

What is pronation vs supination

Answer 41

Supination is when the hand rotates in causing the palm to face up Pronation is when the hand rotates out causing the palm to face down