Exam 3 Review Guide (3) PDF

LECTURE 1 Compare sensory and motor neurons Sensory neurons: - Pseudounipolar - Cell body is outside the CNS within a ganglion - Collect information from the periphery and carry to CNS - Afferent, taking in sensory information - No d...

LECTURE 1 Compare sensory and motor neurons Sensory neurons: - Pseudounipolar - Cell body is outside the CNS within a ganglion - Collect information from the periphery and carry to CNS - Afferent, taking in sensory information - No dendrites Motor neurons: - Multipolar - Cell body and dendrites are located within the CNS - Convey information from the CNS to location outside the CNS - Efferent, carrying information to muscles or glands Describe the connections of a spinal nerve with the spinal cord, including gray and white matter, horns, roots, dorsal root ganglion, and spinal nerve Sensory neurons enter the spinal cord through a nerve called a dorsal root. Cell bodies of sensory neurons are located within the dorsal root ganglion.  Motor neurons leave the spinal cord through a called the ventral root. The spinal nerve forms as both the dorsal and ventral root come together. It carries both sensory and motor neurons. Gray matter: - Darker areas of brain - Little myelin present on cell bodies and dendrites - Don’t appear white White matter: - White areas of brain - Myelin present, has a white color due to high lipid count - Myelinated axons in the CNS Dorsal horn: - Contains sensory neurons - Dorsal half of the spinal cord - Contains gray matter  Ventral horn: - Contains motor neurons - Ventral half of the spinal cord - Has gray matter Describe the relationship of the spinal cord and spinal nerves to the meninges and the vertebral column The meninges are layers of membranous tissue that protect the brain and spinal cord. It consists of the pia, arachnoid mater/subarachnoid space and the dura mater. Pia mater: - Innermost layer - Very thin and contains many blood vessels - Attached to surface of brain and spinal cord Arachnoid mater: - Middle layer - Transparent and delicate structure - External to pia and separated by small space (subarachnoid) - Subarachnoid space contains cerebrospinal to cushion the brain Dura mater: - Outermost layer - Toughest layer, provides protection - Collagen tissue  Vertebral Column: - Spinal cord lies in vertebral canal - Protected by bone - Spinal nerves exit via the intervertebral foramen - Spinal segments forms pairs with spinal nerves (31) - Cervical, Thoracic, Lumbar, Sacral Describe the relationship between a spinal segment and its dermatome and myotome Each spinal segment innervates skin and muscle during early development. Dermatone refers to a band of skin that is innervated by a pair of spinal nerves. Myotome refers to a band of skeletal muscle cells that are innervated by a pair of spinal nerves. Define nerve plexus and name the major body regions innervated by the cervical, brachial, and lumbosacral plexuses A nerve plexus is a network of intersecting nerves. It forms from the merging of ventral rami of spinal nerves with nearby ventral rami. Cervical plexus: Innervates skin and anterior muscles of neck, phrenic nerve (diaphragm and breathing) Brachial plexus: Innervates skin and muscles of upper limb - Axillary nerve (shoulder) - Musculocutaneous nerve (biceps brachii and brachialis) - Median nerve (anterior forearm and thumb) - Ulnar nerve (ulnar side of anterior forearm and majority of hand) - Radial nerve (posterior arm and forearm) Lumbar plexus: Innervates skin and anterior/medial parts of thigh Femoral nerve: anterior (front of thigh) Obturator nerve: medial thigh (close to midline) Sacral Plexus: Innervates skin, glute region, posterior thigh (hamstring), leg and foot Sciatic nerve has two branches: Tibial nerve: posterior thigh and leg, foot Common fibular nerve: lateral and anterior leg, wraps around to front of leg LECTURE 2 Describe the structural classifications of joints Joints can be one of three categories: fibrous, synovial or cartilaginous Fibrous: bones linked by collagen fibers, little movement, sutures in the brain Synovial: most moveable joints, shoulder/knee, articular cartilage found at end of bone, contains a joint cavity with synovial fluid, has a fibrous layer and synovial membrane Cartilaginous: bones liked by cartilage, hyaline (very stable, found in sternum), fibrocartilage (more flexible, found in pelvic bone) Describe in detail the anatomy of the synovial joint, and describe how tendons, ligaments, and accessory structure contribute to their stability and protection Synovial joints: shoulder, elbow, wrist, hip, knee Articular cartilage: protects the ends of bones, and helps absorb compression  Joint cavity: space between two bones that contains lubricating synovial fluid Articular capsule: 2 layers: fibrous (continuous with bone periosteum) and synovial membrane (produces synovial fluid) Tendons (muscle to bone) - Crosses over joints and stabilizes them - Creates movement at joint (hip joint) Ligaments (bone to bone) - Limits bone movement in some directions (prevent dislocation) - Elbow joint  Articular disc: fibrocartilage disc, helps absorb check and compression, meniscus in knee Labrum: fibrocartilage ring, keeps bones aligned, shoulder/hip joints Bursa and tendon sheaths protect from abrasion at synovial joints Bursa - Tissue sac containing synovial fluid - Provides padding and reduces friction - Bursitis (inflammation) Tendon sheaths - Tissue sac containing synovial fluid - Wraps around tendons in the hand - Tendonitis Identify the components of the knee and shoulder joints and describe stabilizing features Knee joint (hinge joint/uniaxial movement) - Tibiofemoral joint is a hinge joint (articulation of tibia and femur) - Patellofemoral joint (important for gliding and stability), runners knee when injured - Knee joint stabilizers: ACL and PCL protect the knee and align femur to tibia bone (ensures femur doesn’t go over tibia) MCL and LCL limit side to side movement of femur over tibia. Medial and lateral meniscus cartilage is made of fibrocartilage and helps absorb shock - Knee muscle stabilizers: quads (anterior, knee extension back to anatomical position) and hamstrings (posterior, knee flexion with foot to glute) Shoulder (glenohumeral) joint (ball and socket joint, multiaxial movement) - Humerus connects to scapula (forms ball and socket) - Stabilizing ligaments = Glenoid Labrum: ring of fibrocartilage that deepens the space for humerus head  Glenohumeral ligaments: supports position of humerus head and secures shoulder to upper arm Stabilizing muscles (4 rotator cuff muscles) 1) Supraspinatus: abducts arm at shoulder 2) Infraspinatus lateral (external) rotation of arm 3) Subscapularis: medial (internal) rotation of arm 4) Teres minor: lateral rotation of arm Describe and perform the movements at synovial joints Flexion: decrease angle between two bones in sagittal plane (foot to glute) Extension: returning to a neutral position anatomical position (foot back down to floor) Hyperextension: going past anatomical position Abduction: increase angle laterally, bring hand away from body on coronal plane Adduction: decrease angle between two bones, bring hand back down towards midline Circumduction: making a circle (shoulder/hip joints) Lateral (external) rotation: rotate away from the midline, angle increases Medial (internal) rotation: rotate back to midline, angle decreases Forearm: Pronation + Supination Pronation: palm down Supination: palm up Ankle Joint: Dorsiflexion and plantar flexion Dorsiflexion: toes up to ankle (walking on your heels) Plantar flexion: point toes down Tarsal bones of foot: Inversion and Eversion Inversion: inner part of foot in air, internal rotation Eversion: inner part of foot on ground, external rotation Jaw and scapula: Protraction and retraction Protraction: shoulders slumped forward Retraction: shoulder back to anatomical position  Jaw and Scapula: Elevation and Depression Elevation: bring shoulders up, shoulder shrugs Depression: shoulders back down Thumb and pinky: opposition and reposition Opposition: thumb to pinky Reposition: back to neutral position LECTURE 3 Describe how organization and attachments of muscles dictate movement  Muscle is encased (covered) by deep fascia which is a type of connective tissue. Groups of muscle will share similar actions. Muscles contract in the direction in which their muscle cells contract, sarcomere Z-lines are pulled to the center. Muscles can only pull, they never push. A single muscle cell will pull on the connective tissue at the end of the muscle and contract. Muscles also have attachment sites for tendons. Origins are attachments on fixed/less moveable bone. Insertions are attachments on more moveable bones. Muscles also differ based on shape and size which one can use to infer the strength of the muscle. Define the terms agonist, antagonist and synergist with respect to muscles acting at a joint Agonist (prime mover): muscle that produces movement Antagonist: muscle that opposes a movement Synergist: muscle that helps the prime mover by adding extra force/reduces unnecessary movement. Fixator: holds a bone in place, provides a stable base for the prime mover Identify and describe muscle actions of: Muscles of head and neck These muscles are small and thin and help with facial expression. Innervated by a cranial nerve. Extrinsic eye muscles: - 6 different muscles - Found in orbit/eye socket, outside of eyeball - Inserts into outer surface of eyeball, helps to move the eye - Innervated by 3 different cranial nerves Muscles of mastication (chewing) - Insert on the mandible, lower jaw - Includes temporalis and masseter (elevate mandible to close jaw) - Innervated by cranial nerve Muscles of Swallowing and Speech  - Found in the oral cavity and throat - Helps move food down the esophagus - Innervated by cranial nerves - Larynx (voice box) that controls vocal cords Muscles of Head movement - Anterior (sternocleidomastoid): head flexion and lateral rotation - Posterior (trapezius): stabilize, laterally flex, and rotate head Muscles of vertebral column Posterior vertebral column (erector spinae group) - Helps with back extension and maintaining posture - Lateral rotation and bending - Assist head extension and rotation - 3 column groups (spinalis, longissimus, and iliocostalis) Muscles of trunk (abdominal cavity & thorax) Thorax (respiratory muscles) - Diaphragm: prime mover of inspiration, contraction expands thoracic cavity - Intercostal muscles: move ribs to expand/reduce chest volume Abdominal Cavity - Rectus abdominis: six pack, flex column - External/internal obliques: helps forward/lateral bending  - Transverse compresses the cavity Muscles of pelvis These muscles support pelvic organs and regulate urination/defecation. Innervated by sacral nerves. LECTURE 4 Identify and describe muscle actions of: Muscles of shoulder (pectoral girdle) and arm Pectoral girdle  - Consists of clavicle and scapula - Trapezius (traps) help to elevate (up) or depress (down) the scapula - Rhomboids: help to retract scapula, bring back to anatomical position - Serratus anterior: located on side of ribcage helps with protraction and raising your arm above your head Movement of humerus - Pectoralis major: flex, adducts (to midline) and medially rotates arm - Deltoids: abducts (raise laterally), axillary nerve - Lat dorsi and teres major extend, adduct and medially rotate arm Rotator Cuff Muscles in Shoulder - Supraspinatus: abduct arm (raise away) - Infraspinatus: laterally rotate arm - Teres minor: laterally rotate arm - Subscapularis: medially rotate arm (anterior part of scapula) Muscles of the arm  - Biceps brachii and brachialis: musculocutaneous nerve, flexes/supinates forearm at elbow joints - Triceps brachii: extends forearm at elbow joint, returns it to anatomical position, radial nerve (posterior/behind) Muscles of forearm and hand Anterior: flex wrist and fingers (innervated by median and ulnar nerves) Posterior: extend wrist and fingers (innervated by radial nerve) Anterior forearm: Hand flexion at wrist: flexor carpi ulnaris, palmaris longus and flexor carpi radialis Side note: carpal tunnel (median nerve passes through, becomes inflamed if overused) Posterior forearm: extension of wrist and fingers, radial nerve Muscles of the hand: Hypothenar: moves pinky finger, ulnar nerve Thenar: moves thumb, median nerve Muscles of hip and thigh (anterior, posterior, lateral compartments) Hip Muscles Anterior Hip : innervated by femoral nerves Iliopsoas (hip flexors): iliacus and psoas major flexes thigh at hip joint Rectus femoris: extends knee as part of the quad muscles Sartorius: flexes hip and knee, laterally rotates thigh at hip joint (long muscle that crosses anteriorly) Posterior Hip: gluteus maximus, helps extend and laterally rotate the thigh Anterior Thigh - Innervated by femoral nerve - Quadriceps femoris, extend the leg at knee - 4 pulls that form a tendon pulling on the tibia - Rectus femoris: extends leg and flexes hip - Vastus lateralis: extend knee - Vastus Medialis: extend knee - Sartorius: lateral rotation of thigh at hip Medial Thigh - Adduction of hip (to midline) - Innervated by obturator nerve Posterior Thigh - Innervated by tibial nerve - Hamstrings: flex leg (foot to butt) at knee joint - Consists of biceps femoris, semitendinosus and semimembranosus Tensor fascia - Present on lateral thigh and acts with the gluteus maximus - Iliotibial tract locks knee in extension and provides lateral stability with help of fascia Muscles of leg (anterior, posterior, lateral compartments) Anterior Leg:  - Innervated by common fibular nerve - Tibialis anterior: dorsiflexion foot (walking with your heels up) - Extensor digitorum longus: extension of toes - Extensor hallucis longus: extension of big toe Lateral leg - Innervated by common fibular nerve - Fibularis longus: eversion of foot and plantarflexion (pointing toes down) Posterior Leg - Innervated by tibial nerve - Gastrocnemius and Soleus: help with plantar flexion, make up calf muscles, soleus is deep to gastrocnemius and the gastrocnemius is most superficial - These tendons (muscle to bone) insert onto the calcaneal tendon - These muscles help with ankle plantarflexion (toes pointed) Identify nerve supply to muscles of upper and lower limbs Upper (brachial plexus) Axillary: shoulder Musculocutaneous: biceps brachii and brachialis Radial: posterior forearm Ulnar: ulnar side of anterior forearm and most of hand Median: muscles in the thumb and anterior forearm Lower (lumbar/sacral plexuses) Femoral: anterior thigh Common fibular: lateral and anterior leg Tibial: posterior thigh (hamstrings and calf) Obturator: medial thigh (adductors, back to midline)  Describe the importance of muscle compartments in the limbs - Deep fascia surround the different muscle compartments - Fascia does not stretch which results in compression of nerve and blood vessels - This can lead to pain and reduced blood flow LECTURE 5 Describe the motor unit A motor unit is a single motor neuron and the cells it controls. This is an all or nothing response. There can be small motor units (muscles in the eye, more control) or big motor units (lower limbs, less precise). Define muscle twitch/tension and explain its relationship to muscle contraction - Myosin produces tension as it pulls on actin during the power stroke and brings the thin filaments towards the middle of the sarcomere. This causes the filaments to overlap, the sarcomere to shorten and the muscle to contract. - Muscle twitch is the response to a single electrical stimulation  - Cross bridge formation leads to muscle tension Describe why muscle responses are graded, and how frequency, strength of stimulation, and motor unit recruitment modulate those responses Muscle responses are graded because there are both fast twitch fibers (eye muscles) and slow twitch fibers (calf). Different tasks require different muscles and amount of energy that needs to be exerted. Muscles can contract to various degrees. Changing frequency refers to temporal summation. Low stimulation frequency: - Muscle has a little time to contract again - Taking a single step - Repetitive, slow walking High stimulation frequency: - No muscle relaxation between stimuli (complete tetanus) - Muscle reaches maximum tension Stimulation strength (motor unit recruitment, activated motor units in muscle): - Sub-threshold stimuli: stimuli produces no muscle contraction - Threshold: first observable muscle contraction occurs The stronger the stimulation, the more more units will be recruited, increasing the force of muscle contraction Describe muscle tone and why it occurs Muscle tone is the idea that muscles are never fully relaxed, they are always slightly contracted. This helps with posture and is driven by involuntary muscle movement. Muscle tone decreases with sleep. Important for reflexes and balance. Describe isometric and isotonic contractions, and concentric and eccentric contractions Isometric: muscle stays the same length as it develops tension  Isotonic: muscle generates force and shortens as it lifts a weight (two types: concentric and eccentric), length of muscle changes Concentric Isotonic: muscle shortens as it does work, bicep curl Eccentric Isotonic: muscle generates force as it lengths Concentric curl (shorten) and eccentric lengthen after muscle contraction LECTURE 6 Describe the 3 metabolic pathways used by muscles to generate ATP Direct Phosphorylation of ADP (immediate supply): - Creatine Phosphate (CP) provides the phosphate needed to convert ADP to ATP - Muscle cells store 2-3 times more CP than ATP, replenishing supplies - Fastest ATP production system, used for quick bursts of energy lasting 10-15 seconds (sprinting)  Anaerobic Respiration (Glycolysis) Short Term Supply: - Glucose from glycogen stores of blood supply - Glycolysis (catabolism, break down) occurs in the cytosol - Glucose is converted to pyruvic acid and releases 2 ATP molecules - No oxygen needed, instead lactic acid builds up due to blood vessel compression - Shorter duration of energy (30-40 seconds) Aerobic Respiration (Long-term) Long Term Supply: - Occurs in the mitochondria, citric acid cycle and oxidative phosphorylation - Requires oxygen, myoglobin (oxygen binding protein) - 32 ATP produced per glucose molecule - Electron transport chain - Prolonged duration of exercise (running a marathon) Describe the sequence by which energy stores are used in the early phases of muscle activity 1) ATP stored in muscles in used first (within the first 10 seconds of exercise) 2) More ATP is regenerated by the help of CP 3) As CP stores start to diminish, 30-40 seconds into the exercise, glycogen stored in muscles is broken down into glucose, then oxidized to form ATP 4) For sustained muscle activity, the body relies on aerobic respiration (needing oxygen, occurring in the mitochondria), produces 32 ATP per glucose molecule Compare and contrast the 3 skeletal muscle fiber types 1) Slow oxidative fibers (slow-twitch, Type I): slow contraction, postural muscles, continual contraction, sustained endurance  2) Fast oxidative fibers (fast twitch, Type IIa): fast contraction, leg muscles in distance runners, aerobic and some anaerobic processes, sprinting/walking 3) Fast glycolytic fibers (fast-twitch, Type IIb): swift/brief contractions, fastest type of fiber, mostly anaerobic (without O2), eye muscles Describe the changes that occur in skeletal muscle with resistance training and endurance training Resistance training (anaerobic): Hypertrophy (larger cells): - Increase in muscle fiber size - More mitochondria, increased ability to produce ATP - Larger glycogen reserves Hyperplasia (more cells): - Increase in the number of muscle fibers, causing the tissue to enlarge (from cell division) - Muscle fibers divide or split Endurance training (aerobic): - Increased repetitions with lower weight (running, swimming, biking) - Increase # of mitochondria within muscle fibers - Increases oxidative enzymes - Fibers make or synthesize more myoglobin Describe the effects of aging on skeletal muscle, and explain why muscles atrophy with disuse Aging: - Reduced muscle recovery and able to heal from injury - Decreased amount of satellite cells (help with muscle/tissue repair) - Fibrosis, decreased muscle flexibility and restriction of movement - Muscle mass decreases with age (begins mid 30s) - Decrease size and power of skeletal muscle - Loss in muscle fiber numbers and diameter (size) Disuse atrophy: - Reduction in size of muscle due to lack of physical activity - Loss of muscle mass - Loss of myofibrils without loss of muscle fibers  - USE IT OR LOSE IT Name other body systems affected by exercise Body composition: prevents obesity (strain on heart and metabolism), BMI (although often inaccurate) Cardiovascular system: stronger heart pump with more muscle mass, increased blood flow to tissues, decrease in blood pressure Mental Health: enhanced learning and memory, lowers risk of depression, releases endorphins, promotes healthy brain patterns/activity Immune system: Pro-inflammatory chemicals released, lower risk of cancer, increase immune cell activity LECTURE 7 - Explain the basic components of a reflex arc No conscious level of thought, both have sensory and motor components. Sensory neurons in the periphery detect a stimulus Receptor, sensory neuron, integration center, motor neuron, effector Describe the function of muscle spindle and Golgi tendon organ receptors Muscle spindle: - Receptors lie between muscle cells in muscles and detect muscle stretch Golgi Tendon: - Receptor lies in the tendons at each end of the muscle and detect tension (force)  Describe the myotatic reflex, withdrawal reflex, and crossed-extensor reflex, and draw each reflex arc Myotatic reflex (stretch reflex) - Muscle stretch activates muscle contraction - Always at work, keeping us upright - Very fast reflex (ankle/knee jerk) Withdrawal reflex - Painful receptors, retract limb from danger - Activates flexor muscles Crossed-extensor reflex - Helps us maintain balance during withdrawal reflex  - Shift weight to opposite limb, limb extensors are activated Describe how peripheral nerve injury affects sensory and motor systems, and explain the terms paresthesia, atrophy, weakness, paralysis, hyporeflexia and areflexia Nerve injury can lead to sensory and motor issues, loss of muscle tone, abnormal reflexes and DRG trauma. Paresthesia: damage to sensory axons from skin, abnormal pain/touch/temp Atrophy: damage one motor unit, loss of muscle mass Paresis: muscle weakness Paralysis: entire muscles exhibits atrophy Hyporeflexia: diminished reflexes Areflexia: no reflexes