Unit 2 Study Questions PDF

Chapter 6: Bones and Bone Tissue Describe the functions of the skeletal system and explain which tissues found in bones perform each function. The skeletal system functions as protection, blood cell formation, fat storage, mineral storage and acid-base homeostasis, movement, and support. Protec...

Chapter 6: Bones and Bone Tissue Describe the functions of the skeletal system and explain which tissues found in bones perform each function. The skeletal system functions as protection, blood cell formation, fat storage, mineral storage and acid-base homeostasis, movement, and support. Protection: made up of bone tissue Blood cell formation: made up of connective tissue called blood. Fat storage: made up of connective tissue such as blood and adipocytes tissue Mineral storage & acid-base homeostasis: compact bone tissue stores calcium and phosphate Movement: skeletal muscle tissue provide movement through bone attachment Support: compact bone tissue provides structural framework List the 5 shapes used to classify bones; come up with 3 examples for each shape. Short : carpals(triquetrum & capitate), tarsals(navicular) Long : metatarsals (metatarsal IV), tibia, ulna Sesamoid: patella, sesamoids (2 bones located on the plantar surface of the first metatarsal aka toe) Irregular: vertebrae (atlas = C1), ethmoid bone, sacrum Flat: skull bones (occipital bone), sternum, coxal bones Draw a long bone and label its parts. Compare and contrast red bone marrow and yellow bone marrow. Red Bone Marrow Yellow Bone Marrow Consist of blood-forming cells Consists of blood vessels and (hematopoietic cells) adipocytes; stores triglycerides Seen mostly in infants and young Seen mostly in adulthood children Provides a constant supply of new blood Replaces red bone marrow after about cells age 5 Describe the components of bone tissue. Bone tissue components are found in organic and inorganic matrices; organic components are collagen, and inorganic components are minerals (like hydroxyapatite) Explain how the extracellular components of bone tissue contribute to the properties of bone tissue. Extracellular Matrix: consists of organic and inorganic matrix Organic matrix- (a.k.a osteoid) composed of collagen (predominantly) which helps bone resist torsion (twisting) and tensile (pulling/stretching) forces; bones are brittle and shatter easily w/o organic matrix Inorganic matrix- composed of minerals (hydroxyapatite) which provide bones w/ strength and ability to resist compression; w/o inorganic matrix, bones are too flexible/can’t resist compression Describe the configuration of structures made of compact bone versus spongy bone. Structures made of compact bone will have osteons, lamellae, lacunae w/ osteocytes, canaliculi, and a central canal Structures made of spongy bone will have trabeculae, lacunae w/ osteocytes, canaliculi, lamellae, osteoclasts, osteoblasts Compare and contrast intramembranous and endochondral ossification. Intramembranous Ossification Endochondral Ossification Involved in fetal development; forms Forms all body bones below the head, many flat bones including skull and except clavicles clavicles Occurs in a mesenchymal membrane; Occurs within a model of hyaline composed of mesenchyme, a sheet of cartilage embryonic connective tissue, that’s rich w/ blood vessels & mesenchymal cells Process follows: 1. osteoblast Process follows: 1. chondrocytes development from mesenchymal cells, 2. become osteoblasts, 2. chondrocytes  Osteoblasts become osteocytes, 3. die, 3. primary ossification center Osteoblasts build early spongy bone & becomes spongy bone & secondary some mesenchyme become periosteum, ossification center develops, 4. 4. Osteoblasts build early compact bone epiphyses finish ossifying Compare the roles of osteoblasts and osteoclasts in bone remodeling. OsteoBlasts Build Bone; they are responsible for bone deposition Osteoclasts break down bone; responsible for bone resorption Compare and contrast longitudinal and appositional (widening) bone growth. Longitudinal bone growth lengthens only long bones; occurs from division of chondrocytes in epiphyseal plate, which consists of 5 cell zones (numbered closest to furthest to epiphysis) 1. Zone of reserve cartilage- contains cells to be called upon to divide if needed 2. Zone of proliferation- contains actively dividing chondrocytes 3. Zone of hypertrophy & maturation- contains mature chondrocytes 4. Zone of calcification- contains dead chondrocytes, some are calcified 5. Zone of ossification- contains calcified chondrocytes & osteoblasts Appositional bone growth make bones wider; occurs in all bones & thickens compact bone of diaphysis; growth in width continues after length depending on hormones, diet, and pressure bones face from forces Describe the effects of growth hormone, testosterone, estrogen, and Vitamin D on bone growth and remodeling. Growth hormone- Increase in rate of mitosis of chondrocytes, in epiphyseal plate promoting longitudinal growth Increase activity in osteogenic cells and activity in zone ossification Direct stimulation of osteoblast in the periosteum, triggers appositional growth Testosterone- primary male sex hormone, contributes to bone growth during puberty, limits longitudinal growth; remodeling- promotes bone density & strength by stimulating osteoblast activity Estrogen- primary female sex hormone, promotes bone growth by inhibiting the closure of the epiphyseal plate in long bones (extending period of long bone growth); remodeling- inhibit bone resorption osteoclast activity & promotes bone formation by increasing osteoblasts; maintains bone density Vitamin D- absorption of calcium and phosphate in intestines; adequate vitamin D ensures that there are enough minerals to build bone; remodeling- enhance calcium absorption which maintains blood calcium, supports activity of osteoblast Describe how parathyroid hormone (PTH) regulates blood calcium levels. Parathyroid hormone regulates blood calcium levels when cells in parathyroid gland detect low blood calcium level and release parathyroid hormone (PTH) into blood, which increases blood calcium ion level; calcium ion concentration returns to normal and negative feedback decreases parathyroid gland secretion of PTH Describe the healing process for bone fractures. Hematoma fills the bone fracture, soft callus forms, bone callus starts to build by the osteoblast, bone remodeling the primary bone is replaced with secondary bone. Chapter 7: The Skeletal System Name all bones of the body and describe their location. Classify each bone by shape. Long Short Sesamoid Irregular Flat Femur Tarsals Patella Scapula Occipital Tibia - Talus - Sesamoids (2) Vertebrae: Parietal Fibula - Calcaneus on thumb - Cervical (7) Temporal Metatarsals (5) - Navicular - Sesamoids (2) - atlas Frontal Humerus - Medial on toe - axis Ribs cuneiform Ulna - C3-C7 - True Ribs (1-7) - Intermediate Radius - Thoracic (12) - False Ribs (8-12) cuneiform Metacarpals(5) - Lumbar (5) - Floating Ribs - Lateral Phalanges (20) Pelvic Bones (11&12) cuneiform -Pubis Sternum - 56 phalanx - Cuboid (including Carpals -Ilium Vomer proximal, middle, - Scaphoid -Ischium Lacrimal Bone and distal) - Lunate Sacrum - Triquetrum Coccyx - Pisiform Hyoid - Hamate - Capitate Ethmoid - Trapezoid Sphenoid - Trapezium Maxilla Mandible Inferior Nasal Concha Zygomatic Palatine Compare and contrast the axial and appendicular skeleton. Axial skeleton is the longitudinal axis of the body. This contains bones of the skull, vertebral column, and the thoracic cage. Appendicular skeleton consists of the upper and lower limbs of the body, as well as the pectoral and pelvic girdles. Why do bones have depressions? Why do bones have openings? Why do bones have projections? - Depressions: allow blood vessels and nerves to travel along a bone or place where two bones can articulate; -ex. Fossa, acetabulum - Openings: enclose delicate structures so they can travel through bone; -ex. Foramen magnum, foramina - Projection: site where ligaments & tendons attach or where bones articulate; -ex. Processes, greater trochanter Name the bones of the skull. How are skull bones joined together? - Frontal bone - Parietal bone - Occipital bone - Temporal bone - Sphenoid bone - Ethmoid bone - Palatine bone - Inferior nasal concha - Lacrimal bone - Zygomatic bone - Vomer bone - Nasal bones - Maxilla - Mandible They are all joined by sutures (fibrous). Which bones of the skull have sinuses and what functions do sinuses serve? within the frontal, sphenoid, ethmoid, and maxillary bones—known collectively as the Paranasal sinuses—are located around the nasal cavity and connect to it through small bony openings. Air flowing through the nasal cavity passes through the openings into the sinuses, where the mucous membranes filter, warm, and humidify the air. The paranasal sinuses also lighten the skull considerably and enhance voice resonance. Which bones form the anterior, middle, and posterior cranial fossae? Anterior- Frontal bones, ethmoid, maybe sphenoid, Middle- sphenoid and temporal Posterior- occipital and temporal Which bones form the orbit? Which bones form the nasal septum? Which bones form the nasal conchae? Orbit Nasal Septum Nasal Conchae made up of the Superior and the frontal bone, perpendicular middle is made which forms the plate of the up of the ethmoid superior and ethmoid bone and bone posterosuperior the vomer Inferior made up  walls; of inferior nasal the maxilla, which conchae forms the posteroinferior wall with a small contribution from the palatine bone; the zygomatic bone, which forms the anterolateral wall; the sphenoid bone, which forms the posterior wall; and the ethmoid, lacrimal, and palatine bones, which together form the medial wall. Describe the function of fetal fontanels. infants have “soft spots” in their skulls. These soft spots, membranous areas called fontanels, result from the ossification process that cranial bones undergo. the the the two the two anterior posterior sphenoid mastoid fontanel, fontanel, fontanels, fontanels, which is which is which are which are located between the located in located at between developing the temple the junction the parietal and on the right of the developing occipital and left lambdoid frontal and bones at the sides where and parietal apex of the the squamous bones lambdoid sphenoid sutures where the suture; bone meets where the coronal several developing and other parietal, sagittal cranial temporal, sutures bones and meet; occipital bones meet. Compare cervical, thoracic and lumbar vertebrae by naming common and unique features. Draw the general structure of a vertebra. Cervical vertebrae Thoracic vertebrae Lumbar vertebrae C1-C7, (T1-T12), (L1-L5), Atlas (C1): Lacking a Costal Facets: Vertebral Body: Larger vertebral body, it Articulation surfaces for and more robust than articulates with the the ribs, allowing for cervical or thoracic occipital bone of the attachment to the vertebrae, due to the skull. thoracic vertebrae. increased weight they Axis (C2): Has a unique support. odontoid process that Spinous Process: Transverse Process: allows for rotational Typically long and More prominent and movement of the head. downward-sloping. laterally directed. Spinous Process: Transverse Foramen: Shorter and more Each cervical vertebra horizontally oriented has a transverse foramen that allows for the passage of the vertebral arteries. How do spinal nerves exit the vertebral column? Intervertebral foramen Describe the curvatures of the spine in a fetus compared to an adult. Fetus: Primarily a single kyphotic curve in the thoracic region. Adult: Multiple curves, including: Cervical lordosis: Forward curve in the neck. Thoracic kyphosis: Backward curve in the upper back. Lumbar lordosis: Forward curve in the lower back. Sacral kyphosis: Backward curve in the sacrum. Describe how the structure of the thoracic cage and how ribs articulate with vertebrae. Structure of the Thoracic Cage Articulating Ribs W/ Vertebrae Ribs: There are 12 pairs of ribs, each Head of the rib: This rounded attached to a thoracic vertebra. They portion articulates with the can be classified into three groups superior and inferior articular based on their attachment to the processes of two adjacent sternum: thoracic vertebrae. Tubercle of the rib: This bony True ribs (1-7): These ribs projection articulates with the attach directly to the sternum transverse process of a via costal cartilage. thoracic vertebra. False ribs (8-10): These ribs attach to the sternum indirectly via the costal cartilage of the seventh rib. Floating ribs (11-12): These ribs do not attach to the sternum at all. Sternum: This flat, long bone is divided into three parts: the manubrium, the body, and the xiphoid process. Describe the formation of the sacrum. How do spinal nerves exit the sacrum? - The sacrum is a triangular-shaped bone formed by the fusion of five sacral vertebrae. These vertebrae fuse together during adolescence, creating a solid, wedge-shaped structure that forms the lower part of the spine. - Spinal nerves exit the sacrum through foramina (holes) located on the posterior side of the bone. These foramina are arranged in pairs, with one foramen on each side of the sacrum. The spinal nerves that pass through these foramina are part of the cauda equina, a bundle of nerve roots that extend from the spinal cord. Name the bones of the pectoral girdle. Clavicle & Scapula Which parts of the scapula and the humerus articulate? Which parts of the humerus articulate with the ulna and the radius? - Scapula & humerus: - [Scapula] “The glenoid cavity, along with the humerus, forms the shoulder joint.” (Source: Book 7.4.1 The Pectoral Girdle) - [Humerus] “The proximal epiphysis of the humerus features a ball-shaped humeral head on its medial side that articulates with the glenoid cavity to form the shoulder joint.” (Source: Book 7.4.2 Humerus) - Humerus & Ulna and Radius: - [Humerus] “features… involved in the humeral articulation with the ulna and radius at the elbow joint: On the anterior side, we find two rounded knobs: the lateral capitulum (capit- = “head”), named for its spherical shape and resemblance to a head, and the medial trochlea (troch- = “wheel”), also named  for its shape, which resembles a wheel or spool of thread.” (Soure: Book 7.4.2 Humerus) - [Radius] “narrow proximal epiphysis is called the radial head, which is a round, flattened structure. It articulates with the capitulum of the humerus to form part of the elbow joint” (Source: Book 7.4.3 Bones of the Forearm: The Radius and Ulna) - [Ulna] has “a U-shaped notch called the trochlear notch, into which the trochlea of the humerus fits… The anterior lip of the trochlear notch is a projection known as the coronoid process, which fits into the coronoid fossa of the humerus.” (Source: Book 7.4.3 Bones of the Forearm: The Radius and Ulna) Describe how the ilium, the ischium, and the pubis fuse to form the pelvic bone. These three bones fuse together at a region called the triradiate cartilage, which is located near the acetabulum (the socket for the femur). The fusion process begins in early childhood and is typically completed by the late teens or early twenties. Which part of the femur articulates with the pelvic bone? Which parts of the femur articulate with the tibia? The head of the femur articulates with the acetabulum of the pelvic bone. This forms a ball-and-socket joint that allows for a wide range of movement. The distal end of the femur articulates with the tibia at the knee joint. The specific parts involved are: Medial condyle of the femur: Articulates with the medial tibial plateau. Lateral condyle of the femur: Articulates with the lateral tibial plateau. Classify the patella. Largest Sesamoid bone Describe the purpose of the three arches of the foot. 1. Medial longitudinal arch: This is the highest of the three arches and runs from the heel to the big toe. It helps to distribute weight evenly across the foot and provides stability during walking and running. 2. Lateral longitudinal arch: This arch runs from the heel to the little toe and is less pronounced than the medial arch. It helps to absorb shock and provides flexibility during movement. 3. Transverse arch: This arch runs across the width of the foot and helps to distribute weight evenly between the forefoot and the hindfoot. Chapter 8: Articulations Describe the classification of joints by function. 1. Synarthrosis(Fibrous) Immovable joints: These joints have no or very limited movement. Examples: Sutures in the skull, gomphosis between teeth and jawbone, Intersseous membrane. 2. Amphiarthrosis(Cartilaginous) Slightly movable joints: These joints allow for slight movement. Examples: Intervertebral discs, symphysis pubis, and epiphyseal plate 3. Diarthrosis(Synovial) Freely movable joints: These joints offer a wide range of motion. Examples: Shoulder joint, elbow joint, hip joint, knee joint. Diarthrosis joints are further classified based on their shape and type of movement: Ball-and-socket joints: Allow for the greatest range of motion, including rotation, flexion, extension, abduction, adduction, and circumduction. (Example: shoulder joint, hip joint) Hinge joints: Allow for flexion and extension in a single plane. (Example: elbow joint, knee joint) Pivot joints: Allow for rotation around a single axis. (Example: joint between the first and second cervical vertebrae) Condyloid joints: Allow for flexion, extension, abduction, and adduction. (Example: wrist joint) Saddle joints: Allow for flexion, extension, abduction, adduction, and circumduction, but not rotation. (Example: joint between the thumb and the wrist) Gliding joints: Allow for slight sliding movements. (Example: intercarpal joints) Do all joints move? Which joints enable movement? joints provide stability? Which joints allow for the growth of long bones? Epiphyseal plate is hyaline cartilage. (These are the 3 functions listed for joints but they do not all apply to every joint.) All joints do not move. Joints that enable movement are Synovial joints. Joints that provide stability are cartilaginous and fibrous joints. The cartilaginous joint (synchondrosis allow for the growth of long bones.The three functions are enabling movement, providing stability, and allowing long bones to lengthen. List the 3 structural classes of joints. Describe the components of each class of joints.List 2 examples of joints in each category.Describe the basic structure of a synovial joint. Use movement terminology to describe specific motions. Synovial greatest range Cartilaginous stable but Fibrous No Mobility with of motion not stable little mobility greatest stability Has joint space/cavity, Has cartilage between United with short filled with fluid between the articulating bones. collagen fibers of dense articulating bones.Had Has no joint space. Are regular connective synovial fluid, articular in epiphyseal tissue. Has no joint capsule, articular plate(synchondrosis), space. Are in coronal cartilage is composed intervertebral joint sutures (sutures), of hyaline cartilage. Are (symphysis). between bones in teeth( diarthroses has an axis: gomphoses), and in Nonaxial(carpals joint ), interosseous Uniaxial(elbow joint ), membranes in Ex. Biaxial(metacarpophala radius and ulna ngeal joint ), Multi or Tri (syndesmosis) Axial: (shoulder joint) Classify various moveable joints of the body according to the type of synovial joint and the movement that occurs at that joint. - Gliding nonaxial the bone slides past each other in a single plane but not around an axis. Found between the intertarsal joints of the ankle and foot as well as the intercarpal joint of the wrist and hand. - Angular movements increase and decrease the angle in articulating bones. Ex: Abduction-Adduction, Extension-Flexion-Hyperextension, Circumduction. - Rotation- Nonangular, pivoting movement. Is when one bone rotates or twists on an imaginary line running down its middle. - Special Movements- Opposition-Reposition, Depression-and Elevation, Protraction- Retraction, Inversion- Eversion, Dorsiflexion- Plantarflexion, and Supination-Pronation. Compare and contrast the structure and function of the elbow and the knee. Describe the stabilizing structures of these two joints and their common injuries. Structure Function Stabilizing Common Injuries Structure  Elbow: Elbow: Elbow: A hinge joint Primarily Elbow: formed by the responsible for Tennis elbow: humerus, ulna, bending and Ligaments: Ulnar Inflammation of and radius. The straightening the collateral the tendons that primary arm. ligament (UCL), attach to the movement is Knee: radial collateral outside of the flexion and Primarily ligament (RCL), elbow. extension. responsible for annular ligament. bending and Golfer's elbow: Knee: straightening the Muscles: Biceps Inflammation of A complex hinge leg, but also brachii, triceps the tendons that joint formed by plays a role in brachii, attach to the the femur, tibia, weight-bearing brachialis. inside of the and patella. and stability. elbow. Knee: While primarily allowing flexion Fractures: Ligaments: Fractures of the and extension, it Anterior cruciate also has a limited humerus, ulna, or ligament (ACL), radius. range of posterior rotational cruciate ligament Knee: movement. (PCL), medial collateral ACL tear: ligament (MCL), Rupture of the lateral collateral anterior cruciate ligament (LCL). ligament. Meniscus: Medial MCL sprain: meniscus and Injury to the lateral meniscus. medial collateral ligament. Tendons: Patellar tendon, Meniscus tear: quadriceps Injury to the tendon. cartilage in the knee joint. Muscles: Quadriceps, Patellar hamstrings. tendonitis: Inflammation of the patellar tendon. Arthritis: Degeneration of the cartilage in the knee joint. Compare and contrast the structure and function of the shoulder and the hip. Describe the stabilizing structures of these two joints and their common injuries. Structure Function Stabilizing Common Injuries Structure Shoulder: Shoulder: Shoulder: Shoulder: A ball-and-socket Primarily joint formed by the responsible for Ligaments: Rotator cuff tear: humerus and the arm movement, Acromioclavicular Injury to one or glenoid cavity of including flexion, ligament, more of the rotator the scapula. It extension, coracoclavicular cuff muscles. allows for the abduction, ligament, greatest range of adduction, glenohumeral Dislocation: The motion of any joint rotation, and ligaments. humerus slips out in the body. circumduction. of the glenoid Hip: Hip: Rotator cuff cavity. A ball-and-socket Primarily muscles: joint formed by the responsible for leg Supraspinatus, Impingement femur and the movement, infraspinatus, syndrome: acetabulum of the including flexion, teres minor, Inflammation of pelvis. While also a extension, subscapularis. the rotator cuff ball-and-socket abduction, tendons due to joint, it is more adduction, Hip: compression. stable than the rotation, and shoulder due to its circumduction. It Ligaments: Hip: deeper socket and also plays a crucial Iliofemoral surrounding role in ligament, Hip dysplasia: muscles. weight-bearing. pubofemoral Abnormal ligament, development of the ischiofemoral hip joint. ligament. Hip fracture: Break Labrum: A ring of in the femur near cartilage that the hip joint. deepens the acetabulum. Labral tear: Injury to the cartilage Muscles: Gluteus that lines the maximus, gluteus acetabulum. medius, gluteus minimus, quadriceps, hamstrings. Explain the trade-off between the mobility versus the stability of a joint. Refer to Figure 8.12 for specific examples along this continuum. A joint that is highly mobile, like the shoulder, allows for a wide range of movement. However, this mobility comes at the cost of stability. Conversely, a joint that is highly stable, like the hip, provides greater support but limits the range of motion. Which specific joint is the most mobile but least stable joint in the body? Describe why. The shoulder joint is the most mobile but least stable joint in the body. Ball-and-Socket Structure: The shoulder is a ball-and-socket joint, which allows for the greatest range of motion of any joint in the body. This mobility is due to the shape of the humerus (ball) fitting into the shallow glenoid cavity of the scapula (socket).Compared to the deep socket of the hip joint, the glenoid cavity of the shoulder is relatively shallow. This shallowness contributes to the joint's instability. The shoulder joint is supported by a relatively loose network of ligaments, which allows for greater mobility but also makes it more susceptible to dislocation. Chapter 9: The Muscular System Describe the structural organization of a muscle such as the brachialis muscle. Include the connective tissue layers that hold it together and connect the muscle to bone. Muscle Cell fiber (Endomysium) -> Fascicle (Perimysium) -> Skeletal Muscle (Epimysium) -> Muscle Fascia -> Tendon - Bone Describe the classification of muscles by shape according to the arrangement of fascicles. - Parallel Muscles: Fascicles run parallel to the long axis of the muscle (straplike muscle); ex. sartorius - Convergent Muscles: fascicles are broad at one end and short at the tendon; ex. Pectoralis major muscle  - Pennate Muscles: fibers & fascicles attach to tendon in way that resembles a feather; comes in 3 variations - Unipennate: one tendon, fascicles feather out from one side of tendon; ex. Flexor pollicis longus muscle - Bipennate: one tendon, fascicles feather out from both sides of tendon; ex. Rectus femoris muscle - Multipennate: several tendons, fascicles resemble several feathers joined together; ex. Deltoid muscle - Circular Muscles: encircles a structure and also called sphincters; ex. Orbicularis oculi muscle - Spiral Muscles: wrap around bone, have twisted appearance; ex. Supinator muscle - Fusiform Muscles: thicker in the middle, shorter at ends; ex. Biceps brachii muscle Describe what the words used in the name of a muscle can tell you about that muscle. (Reference the Muscle Names Activity.) Term and Meaning Example Muscle Size Brevis—short Fibularis brevis muscle Longus—long Adductor longus muscle Vastus—wide/large Vastus lateralis muscle Muscle Location Anterior—toward the front Tibialis anterior muscle External—toward the outside External intercostal muscle Infra—below Infraspinatus muscle Intercostal—between the ribs Internal intercostal muscle Internal—toward the inside Internal oblique muscle Posterior—toward the back Tibialis posterior muscle Profundus—deep Flexor digitorum profundus muscle Superficialis—nearer the surface Flexor digitorum superficialis muscle Supra—above Supraspinatus muscle Muscle Action Abductor—pulls away from the Abductor pollicis longus muscle midline Adductor—pulls toward the midline Adductor magnus muscle Depressor—pulls down Depressor labii inferioris muscle Erector—holds erect or straight Erector spinae muscle Extensor—increases the angle Extensor digitorum longus muscle between bones Flexor—decreases the angle between Flexor digitorum longus muscle bones Levator—raises a body part Levator scapulae muscle Pronator—turns palm posteriorly Pronator teres muscle Supinator—turns palm anteriorly Supinator muscle Body Region Abdominis—abdominal area Rectus abdominis muscle Brachii—arm area Biceps brachii muscle Capitis—head area Semispinalis capitis muscle Carpi—wrist area Extensor carpi ulnaris muscle Cervicis—neck area Splenius cervicis muscle Digitorum/Digiti—related to Extensor digitorum muscle fingers/toes Femoris—femur or thigh Biceps femoris muscle Gluteal—buttocks Gluteus maximus muscle Hallucis—great toe Abductor hallucis muscle Oculi—eye area Orbicularis oculi muscle Oris—mouth area Orbicularis oris muscle Pectoralis—chest area Pectoralis minor muscle Pollicis—thumb Flexor pollicis brevis muscle Muscle Fiber Orientation Oblique—at an angle External oblique muscle Orbicular—circular Orbicularis oculi muscle Rectus—straight Rectus femoris muscle Transversus—across/transverse Transversus abdominis muscle Muscle Heads Biceps—two heads Biceps brachii muscle Quadriceps—four heads Quadriceps femoris muscle group Triceps—three heads Triceps brachii muscle Muscle Shape Deltoid—triangular (as in the Greek Deltoid muscle letter delta) Maximus—largest Gluteus maximus muscle Minimus/Minimi—smallest Gluteus minimus muscle Minor—small Pectoralis minor muscle Quadratus—shaped like a rectangle Pronator quadratus muscle Rhomboid—shaped like a rhombus Rhomboid major muscle Serratus—serrated or jagged Serratus anterior muscle Trapezius—shaped like a trapezoid Trapezius muscle Describe the functions of skeletal muscle, which include actions, facial expression, breathing, and generating heat. A muscle contraction produces tension. How does muscle tension result in these specific functions? Skeletal muscle functions to provide movement by pulling and contracting on bones Muscle tension is the force generated when a muscle contracts; actions arise from muscle tension to produce movement; facial expressions arise from muscle tension by pulling on facial muscles; breathing arises from muscle tension by contraction of the diaphragm; generating heat (shivering) arises from muscle contraction of body Describe the difference between a muscle’s origin and insertion. Muscle Origin- the part that the muscle attaches that is more fixed (stationary) Muscle Insertion- the part that the muscle moves Use the correct vocabulary words to describe muscle action: agonist, antagonist, synergist, and fixator. -Agonist: (a.k.a. Prime mover) the muscle providing most of the force in a movement; ex. Brachialis muscle -Antagonist: lies opposite of the agonist & slows down the action; ex. Triceps brachii muscle -Synergist: work together w/ agonist to guide movement; ex. Biceps brachii to brachialis -Fixator: holds the muscle in place, makes movement more efficient; ex. Supraspinatus muscle Practice naming muscles using the Lab Manual taglist, the Complete Anatomy app, and the Practice Anatomy Lab. Also there are short videos that demonstrate the movements of different muscles if you look in the Mastering A&P Study Area under Animations. Remember, muscles can only PULL, they cannot push. Use your knowledge of joint movements and muscle actions to predict how muscles work together to create specific movements. Your book demonstrates this with an illustration of the muscles used to walk up stairs, in Figure 9.26 (Section 9.6). Chapter 10: Muscle Tissue and Physiology Part 1: Muscle Tissue (Textbook Modules 10.1-10.4) Define: contractility, excitability, conductivity, distensibility, and elasticity, as related to muscle cells. -Contractility ability of the cells to contract. - Excitability responsive in the presence of various stimuli - Conductivity the electrical changes across the plasma membrane - Distensibility the ability to be stretched without damage to the muscle tissue - Elasticity- the ability to return to the original shape after being stretched. Describe the structure of the muscle cell using myocyte-specific vocabulary: sarcolemma, sarcoplasm, sarcoplasmic reticulum. 1. Sarcolemma: This is the plasma membrane of the muscle cell. It encases the muscle fiber and is crucial for conducting the electrical impulses necessary for muscle contraction.  2. Sarcoplasm: Think of this as the cytoplasm of the muscle cell. It’s the intracellular fluid that contains all the organelles, including myofibrils, mitochondria, and the sarcoplasmic reticulum. It also has a high concentration of glycogen and myoglobin, which are essential for energy storage and oxygen binding. 3. Sarcoplasmic Reticulum (SR): This network of tubules is similar to the endoplasmic reticulum in other cells but specialized for muscle cells. It plays a pivotal role in storing and releasing calcium ions, which are crucial for muscle contraction. All these components work together to enable muscle function. Name the proteins found in thick and thin myofilaments of muscle cells. Which proteins are contractile and which proteins are regulatory? Which proteins are found in the light and dark stripes of muscle cell striations? Thick Myofilaments: Main Protein: Myosin ○ Role: Contractile protein ○ Location: Found in the dark stripes (A bands) of muscle cell striations. Thin Myofilaments: Main Proteins: Actin, Tropomyosin, Troponin ○ Actin ○ Role: Contractile protein ○ Location: Found in the light stripes (I bands) of muscle cell striations. ○ Tropomyosin and Troponin ○ Role: Regulatory proteins ○ Location: Associated with actin in the light stripes (I bands). Striations in Muscle Cells: A Bands (Dark Stripes): Myosin (and overlapping actin) I Bands (Light Stripes): Actin, tropomyosin, and troponin Why do we say that the sarcomere is the functional unit of contraction?Explain the sliding filament mechanism of contraction. It is a repeating unit within a muscle fiber that is responsible for generating force. The sliding filament mechanism is the process by which muscles contract. It involves the interaction between the actin and myosin filaments within the sarcomere. When a muscle is stimulated to contract, the following steps occur: 1. Calcium Release: Calcium ions are released from the sarcoplasmic reticulum, a specialized organelle within the muscle fiber. 2. Tropomyosin Shift: Calcium ions bind to troponin, causing it to change shape and move tropomyosin off of the actin binding sites. 3. Myosin Binding: Myosin heads bind to the exposed actin binding sites. 4. Power Stroke: The myosin heads pivot, pulling the actin filaments towards the center of the sarcomere. This action shortens the sarcomere and causes the muscle to contract. 5. Detachment and Reattachment: The myosin heads detach from the actin filaments and reattach to new binding sites, repeating the power stroke. This process continues as long as there is a sufficient supply of calcium ions and ATP (the energy currency of the cell). When the muscle is no longer stimulated, calcium ions are reabsorbed into the sarcoplasmic reticulum, tropomyosin covers the actin binding sites, and the muscle relaxes. Draw the Neuromuscular Junction. Use specific terminology to label the Neuron’s part, the Muscle’s part, and circle the whole junction. Where is the synaptic cleft? How does the neuron signal to the muscle that the muscle should contract? The neuron signals to the muscle that the muscle should contract through a process called neuromuscular transmission. Where does the muscle cell have voltage-gated calcium channels? What is their role in contraction? Voltage-gated calcium channels are primarily found in the T-tubules of muscle cells. Action Potential Propagation: When an action potential arrives at the neuromuscular junction, it travels along the sarcolemma and into the T-tubules. Calcium Channel Opening: The depolarization of the T-tubule membrane opens voltage-gated calcium channels. Calcium Release: The opening of these channels allows calcium ions to flow from the extracellular space into the T-tubule. Describe the key events in each of the following:  Excitation Nerve impulse: A nerve impulse travels down a motor neuron to the neuromuscular junction. Acetylcholine release: At the neuromuscular junction, acetylcholine (ACh) is released into the synaptic cleft. ACh binding: ACh binds to nicotinic receptors on the muscle fiber's motor end plate. Muscle action potential: This binding opens ion channels, causing a muscle action potential to propagate across the sarcolemma and down the T-tubules. Excitation-contraction coupling Calcium release: The action potential triggers the release of calcium ions from the sarcoplasmic reticulum (SR) into the sarcoplasm. Preparing for contraction Calcium binding: Calcium ions bind to troponin, a protein complex associated with actin filaments. Tropomyosin movement: This binding causes tropomyosin, another protein, to move away from the actin binding sites. Contraction Crossbridge formation: Myosin heads bind to exposed actin binding sites on the thin filaments, forming cross bridges. Power stroke: The myosin heads pivot, pulling the actin filaments towards the center of the sarcomere. Crossbridge detachment: ATP binds to the myosin head, causing it to detach from the actin filament. Reactivation: The myosin head hydrolyzes ATP, returning it to a high-energy state, ready for another cycle. Relaxation Calcium reuptake: Calcium ions are pumped back into the SR, reducing the intracellular calcium concentration. Tropomyosin return: With lower calcium levels, troponin releases calcium, allowing tropomyosin to cover the actin binding sites again. Crossbridge detachment: Without calcium, myosin heads detach from actin, and the muscle relaxes. Describe the movement of the myosin heads during the crossbridge cycle. Attachment: The myosin head binds to an actin filament, forming a crossbridge. Power stroke: The myosin head pivots, pulling the actin filament towards the center of the sarcomere. This movement shortens the muscle fiber. Detachment: The myosin head detaches from the actin filament. Reactivation: The myosin head binds to another ATP molecule, which reactivates it for another cycle. How long will the crossbridge cycle continue? What are the limiting factors? The crossbridge cycle will continue as long as there is a sufficient supply of ATP and calcium ions. Limiting Factors include: ATP depletion: Without ATP, the myosin head cannot detach from the actin filament, preventing the crossbridge cycle from continuing. Calcium ion removal: When calcium ions are pumped back into the sarcoplasmic reticulum, the troponin-tropomyosin complex covers the actin binding sites, preventing crossbridge formation. Muscle fatigue: Prolonged muscle activity can lead to fatigue, which is characterized by a decrease in muscle force production. This can be due to factors such as glycogen depletion, lactate accumulation, or nerve fatigue. Where do you find acetylcholinesterase and what is its role in muscle contraction?  - Acetylcholinesterase (AChE) is an enzyme found at the neuromuscular junction, the synapse between a motor neuron and a muscle fiber. The roles of Acetylcholinesterase is : - Breakdown of Acetylcholine: After a nerve impulse triggers the release of the neurotransmitter acetylcholine (ACh) into the synaptic cleft, AChE rapidly breaks down ACh into its components: acetate and choline. - Termination of Signal: By breaking down ACh, AChE effectively terminates the muscle contraction signal. This prevents continuous muscle contraction and ensures precise control of muscle movements. - Recycling of Choline: The breakdown of ACh also releases choline, which can be taken up by the motor neuron and recycled to synthesize new ACh. This helps maintain the supply of ACh for future nerve impulses. Note: We will study the Action Potential in depth in Chapter 11, so we’ll save it for that. Part 2: Muscle Physiology (Textbook Modules 10.5-10.9) Describe the source of energy for a muscle fiber at 10 seconds; 60 seconds; or 5 minutes of contraction. 10 seconds: ATP (Adenosine Triphosphate): The immediate source of energy for muscle contraction. It's stored in small quantities within the muscle fibers. 60 seconds: Glycolysis: The breakdown of glucose into pyruvate, producing ATP. This process occurs in the cytoplasm of muscle fibers and doesn't require oxygen. 5 minutes:  Oxidative phosphorylation: The breakdown of pyruvate and fatty acids in the mitochondria, producing ATP with the aid of oxygen. This process is more efficient than glycolysis but takes longer to initiate. Compare and contrast glycolytic catabolism and oxidative catabolism. Glycolytic Catabolism Location: Cytoplasm Oxygen requirement: Anaerobic (does not require oxygen) Efficiency: Produces a smaller amount of ATP per glucose molecule compared to oxidative catabolism. Oxidative Catabolism Location: Mitochondria Oxygen requirement: Aerobic (requires oxygen) Efficiency: Produces a significantly larger amount of ATP per glucose molecule compared to glycolytic catabolism. Compare and contrast fast-twitch fibers and slow-twitch fibers. Fast-Twitch Fibers Contraction speed: Rapid Fatigue rate: High (easily fatigued) Myoglobin content: Low Mitochondrial density: Low ATP production: Primarily through glycolysis Typical activities: Explosive power activities (e.g., sprinting, jumping) Slow-Twitch Fibers Contraction speed: Slow  Fatigue rate: Low (resistant to fatigue) Myoglobin content: High Mitochondrial density: High ATP production: Primarily through oxidative phosphorylation Typical activities: Endurance activities (e.g., marathon running, long-distance swimming) Describe the length-tension relationship and what it means for muscle contraction. The relationship between the length of a muscle fiber and the amount of tension it can produce. Muscle strength: The length of a muscle at the time of contraction can significantly affect its strength. Range of motion: The length-tension relationship helps explain why muscles have optimal ranges of motion for producing maximum force. Muscle injuries: Excessive stretching or shortening of muscles can lead to injuries, as they operate outside of their optimal length rang Compare and contrast Type I and Type II muscle fibers. Type I (Slow-Twitch) Fibers Contraction speed: Slow Fatigue resistance: High Myoglobin content: High Mitochondrial density: High ATP production: Primarily through oxidative phosphorylation Typical activities: Endurance activities Type II (Fast-Twitch) Fibers  Contraction speed: Fast Fatigue resistance: Low Myoglobin content: Low Mitochondrial density: Low ATP production: Primarily through glycolysis Typical activities: Explosive power activities What is a motor unit? Describe how more motor units are recruited and how that affects the force of a muscle contracting. A motor unit is the functional unit of a muscle. It consists of a motor neuron and all the muscle fibers it innervates. Recruitment of motor units is the process of increasing the number of motor units activated to produce a greater force. When a muscle needs to contract with more force, the nervous system gradually recruits additional motor unit Graded contraction: By recruiting more motor units, the nervous system can produce a graded contraction, meaning the muscle can generate a wide range of forces. Size principle: Motor units are typically recruited in order of size, starting with the smallest motor units and gradually increasing to the largest. This allows for a smooth and controlled increase in force. Force production: As more motor units are recruited, the total number of muscle fibers contracting increases, leading to a greater overall force. Describe the difference between isotonic concentric, isotonic eccentric, and isometric contraction.  - Isotonic concentric- this occurs when the muscle shortens while exerting a constant force. Ex:lifting a weighs upwards - Isotonic eccentric- occurs when the muscle lengthens while exerting a constant force.Ex: lowering a weight slowly - Isometric concentration This occurs when the muscle does not change in length while exerting force. Ex:lifting the weight abducting without flexing the arms How do endurance training and resistance training affect the structure and biochemistry of skeletal muscle fibers? Endurance Training is seen when you do activities that involve more repetition with lighter weight like cycling, jogging, and distance swimming just to name a few. The structure and biochemistry due to these exercises the muscle fiber has an increase in the number of oxidative enzymes, more mitochondria and mitochondrion protein available, and a higher number of blood vessels. With these ad What causes muscular fatigue? Why do you need more oxygen during the recovery period? -Depletion of key metabolics(like glycogen, and blood glucose), decreased availability of oxygen to muscle fibers, Accumulation of certain chemicals. Environmental conditions(Extreme heat). -During the recovery period because your body now is at an oxygen deficiency/debt. As the rate and depth of ventilation increases more carbon dioxide is exhaled, helping to return the body to its normal homeostasis. The body needs oxygen to produce ATP and glycogen, which are essential for muscle function. Improve circulation: Increased oxygen intake can help to improve blood flow and circulation, which is essential for delivering nutrients and removing waste products from the muscles. Repair muscle damage: Oxygen is necessary for the  repair and rebuilding of muscle fibers that may have been damaged during exercise. How are smooth muscle cells different from skeletal muscle cells (structurally)? Shape Organize SR Myofibrils Smooth muscle cells: Smooth muscle cells: Smooth muscle cells: Smooth muscle cells: These cells are They are arranged in Have a less developed Lack organized spindle-shaped, with sheets or layers, often SR, with fewer myofibrils, resulting in tapered ends and a oriented in multiple cisternae. a less striated central nucleus. directions. appearance. Skeletal muscle cells: Skeletal muscle cells: Skeletal muscle cells: Skeletal muscle cells: These cells are long, They are grouped into Have a well-developed Contain numerous multinucleated fibers bundles called SR with extensive myofibrils, composed with striations fascicles, which are cisternae that store of thick (myosin) and (alternating light and surrounded by calcium ions. thin (actin) filaments, dark bands). connective tissue. arranged in a highly organized pattern. What role does calcium play in the contraction of smooth muscle? calcium acts as a key signaling molecule in smooth muscle contraction. By binding to calmodulin and activating MLCK, calcium initiates the phosphorylation of myosin light chains, which is essential for the cross-bridge formation and subsequent muscle contraction. Where do you find smooth muscle and what functions does it serve? Blood vessels, digestive system, respiratory system, urinary system,reproductive system, eye. The function of contraction, relaxation, regulation of the physiological process. What stimulates smooth muscle to contract? Nerve impulses, Hormones, Stretch: