Lecture Exam 2 Flashcards
What is a joint?
- 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
List the joints by functional classification (immoveable, slightly moveable, freely moveable)
Synarthroses - Immovable joints
Amphiarthroses - Slightly movable joints
Diarthroses - Freely movable joints
Name the joints based on structural classification and examples.
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
What are the three types of fibrous joints? What is the structure like? Give examples.
Suture
- Joint held together by short interconnecting fibers. Only in skull
Syndesmosis
- Joint held together by ligament
Gomphosis
- Peg in socket fibrous joint
What are two main types of cartilaginous joints? What is the structure like? Give examples.
Synchondroses
- Bones jointed by cartilage (ribs and sternal connection)
Symphyses
- Bones united by fibrocartilage (spine and pubic symphysis)
What is abduct, adduct, extend, flexion? What type of movement is involved in jumping jacks and bending the knee?
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
What is the structure of the synovial joints? What is their function?
- 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.
What are the six types of synovial joints discussed in lecture?
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
What are two compound synovial joints?
Elbow joint
- Includes humerus, radius, and ulna
Knee joint
- Includes femur, tibia, and fibula
List three factors that influence synovial joints stability (in order of importance of role)
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
What are the key features of the shoulder joint?
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
What are key features of the knee joint?
- 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
What is Arthritis? What are the causes?
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
What is the integumentary system? What are the functions?
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
What are the characteristics of epidermis? Layers? Cell types?
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)
What are the characteristics of dermis? What structures are in dermis?
Dermis:
- Connective tissue
- Highly vascularized and innervated
- Thermoregulation
Structures:
- Hair bulb, sebaceous gland, eccrine gland, apocrine gland, arrector pili muscle, nerves, blood vessels
What are the two layers found in dermis? What are they composed of?
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
What are the appendages of the skin and what layer are they found in? Know the characteristics and structures associated.
- 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
What is the structure of hair?
- 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
What are cutaneous glands?
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
What are the differences between 1st, 2nd, 3rd degree burns? Why can serious burns be life threatening?
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)
What are three types of muscle? Classify according to histology and function. Which muscle type is multinucleated?
Smooth
- Nonstriated, involuntary, spindle shaped
Cardiac
- Striated, involuntary, branched, cardiocytes
-intercalated disks
Skeletal
- Striated, voluntary, myofibers
Label a diagram of whole muscle(as well as a diagram of a single fiber
Draw and label a sarcomere and associated structures. Which bands change length with contraction? Why do regions shorten while others do not?
Bands that contract:
- I band
- H band
Non contracting components:
- M line
- Z disc
- A band
What is the function of transverse tubules, sarcoplasmic reticulum, terminal cisternae, and triads?
- 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
Describe the events of muscle contraction? How are actin, myosin, tropomyosin and troponin involved?
- Cross bridge is resting (ATP)
- Troponin does not have Ca, tropomyosin is covering attachment site of actin
- Electric signal causes release of Ca from Sarcoplasmic Reticulum (SR)
- 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)
- Myosin head does power stroke(pull) using the energy from hydrolysis of ATP into ADP+Pi and releases ADP+Pi
- Once ATP binds to myosin head the crossbridge is broken and the cycle can start once a new ATP binds
What are nerves? What are dendrites? What is the axon hillock?
- 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
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?
- 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.)
How does innervation of muscles work? Label a neuron and know its function. What is action potential with respect to muscle?
- 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
What is the neuromuscular junction? What is a motor unit? What makes contractions occur?
- 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
Label the muscles by type and name
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
