Skin, Muscles and Bones The Integumentary System – Organs Skin Hair Nails Sweat and Sebaceous Glands Skin • Integument is a covering • Includes the hair, nails, sweat glands and oil producing glands • Largest Body Organ ~ 21.5 square feet of skin and has the following functions • Protects the body from injury • Protects the body from intrusion of harmful microorganisms • Protects body from the UV rays of the sun • Helps to maintain the proper internal temperature of the body • Serves as a site for exertion of waste through perspiration • Serve as an important sensory organ Thickness • Varies – depending on the part of body that is being covered and its function in covering that part. • E.g. Skin on the upper back is much thicker than skin on the eyelid. Why might this be? Parts of the Skin • Epidermis: is the outer layer of skin and consists of several sublayers • Stratum corneum: top sublayer, containing a flat layer of dead cells arranged in parallel rows, as new cells are produced – dead cells are shed off. • Stratum germinativum: bottom sublayer of the epidermis. New cells produced and pushed up to the stratum corneum • Melanin: specialized cells that produce a pigment, which helps determine skin and hair color. Helps screen out sun’s UV ray overexposure to which causes skin cancer. • Dermis: contains connective tissues that hold many capillaries, lymph cells, nerve ending, sebaceous and sweat glands and hair follicles. • they nourish the skin layer and lead to it serve as sensitive touch receptors. • Papillary layer/ top layer of the determines fits into ridges on the stratum germinativum to form lines that are unique to each individual (on the fingers these are your fingerprints!) • Skin also changes the shade based on the about of oxygenated blood in the dermis – oxygen is carried by pigmented red blood cells called hemoglobin, if it has a lot of oxygen, it will be red, leading to a pinkish hue. If there is low blood oxygen, the skin looks pale or blueish • Which is why often, blue lips indicate suffocation or some other obstructions in the respiratory tract. • Subcutaneous layer: is the layer between the dermis and the body’s inner organs. • Consists of fatty tissue (to protect the inner organs and maintain body temperature) and some layer of fibrous tissue. • Contains blood vessels and nerves Hair • Grows from the epidermis to cover various parts of the body • Cushions and protects areas that it covers • Two parts: • The shaft (above the skin) • The root (beneath the skin surface) • Hair grows upward from the root through the hair follicles • Most contain an arrector pili muscle – when you get cold or nervous these muscles contract, causing goose bumps to form. • Shape of follicle → shape of hair • Hair color – determines by presence or lack of melanin • Think what would dark straight hair follicles look like? • Plates made of hard keratin that cover the dorsal surface of the distal bones of the fingers and toes Nails • Protective covering, help us grasp object and allow us to scratch • Healthy nails look pink-ish Sweat and Sebaceous Glands Sweat I.e. sudoriferous glands • Allows for us to cool down and regulate body temperature • Secrete outwards towards the surface of the body through ducts – called exocrine glands • Exit through pores or tiny opening of skin surface Sebaceous Glands • Located in dermis • Secrete oily substances called sebum – found at the base of the hair follicle • Lubricates as protects the skin + forms a skin barrier against bacteria and fungi • Also softens the surface of the skin Check your understanding: What might cause someone to have dark brown, curly hair? • Blonde, wavy hair? Identify ways to prevent skin cancer. Diseases and Disorders of the Integumentary System Lesion Micro-organism related diseases Other diseases and disorders Lesions • Tissues that have become altered because of disease or disorder • Two types of lesions • Primary: • Appear on previously normal skin • Secondary • Result from change in primary lesion • Usually involve either loss of skin surface or material that forms on the skin surface • Vascular lesions – blood vessel lesions that show through the skin Micro-Organism Related Diseases • Common Diseases that can be caused by virus or other micro-organism • Rubella (German Measles) • Chicken Pox (Varicella Zoster) • Herpes Zoster (can cause shingles) • Someone who had chicken pox ~20% chance of developing shingles • Inflammation that affect nerves on one side of the body and results in skin blisters. Very painful • Herpes Simplex 1 – cold sores or fever blisters • Tinea, or ringworm, in a fungal infection – on the foot it is called athletes foot (tinea pedis) on the scalp it is scalp ringwork (tinea capitis) 3 types of Skin Cancer More than 90% of skin cancers are on sun exposed skin (usually the face, neck, ears, forearms, hands) Change of color, size, shape or texture of a mole is a common indicator Skin Cancer Bleeding or itching mole is another indicator Basal cells and squamous cell carcinomas cause serious illness (if untreated can cause serious damage, disfigurement, or death) Malignant melanoma causes more than 75% of all deaths from skin cancer Can spread to other organs – most commonly lung and liver The Skeletal System Purpose • Newborn babies are born with over 300 bones – some of these will fuse later leaving the mature adult with 208 bones in their skeleton • ~14% of the body weight • The skeletal system: • Provides a framework for the body • Protects vital organs (brain and spinal cord) • Serve as a lever – where muscles attach to help us lift and move • Store calcium (to be later reabsorbed into the blood if we don’t have enough in our diet) • Produce blood cells in the bone marrow • Question: Explain why babies are born with a “soft spot” on their heads. • Bones are made up of living tissue—bone cells, fat cells, and blood vessels. • •Compared to other body systems, the human skeletal system is extremely hard and durable. • •Bones themselves are composed primarily of the mineral calcium. • •People whose diet is low in calcium may find their bones becoming increasingly brittle and breakable—a major concern for older people (osteoporosis). • Long Bones Short Bones Types of Bones Flat Bone Irregular Bones Sesamoid Bones Long Bones • Form arms and legs – function is support the weight of the body and facilitate movement • Is solid, does not bend easily • Long bones are mostly located in the appendicular skeleton and include bones in the lower limbs (the tibia, fibula, femur, metatarsals, and phalanges) and bones in the upper limbs (the humerus, radius, ulna, metacarpals, and phalanges). • Oxygen and nutrients come from the blood stream to compact bone • At the end of the shaft of the bone (epiphysis), it is shaped to connect to other bones by ligaments or muscles. This is covered by cartilage to protect the bone at the moveable points Short Bones • Small, cube shaped bones of the wrist, angles and toes • Consist of an outer layer of compact bone with an inner layer of cancellous bone or bone with a lattice work structure Flat Bones • Have flat and thin surfaces and found around the roof of the skull • Cover organs or provides a surface for large area of muscles (shoulder blade) • There are flat bones in the skull (occipital, parietal, frontal, nasal, lacrimal, and vomer), the thoracic cage (sternum and ribs), and the pelvis (ilium, ischium, and pubis). The function of flat bones is to protect internal organs such as the brain, heart, and pelvic organs. • Include odd-looking bones, such as the sphenoid bone or vertebrae Irregular Bones • The spine is the place in the human body where the most irregular bones can be found. There are, in all, 33 irregular bones found here. The irregular bones are: the vertebrae, sacrum, coccyx, temporal, sphenoid, ethmoid, zygomatic, maxilla, mandible, palatine, inferior nasal concha, and hyoid. Sesamoid Bone • Unusual small, flat bones wrapped with tendons that move over bony surfaces (e.g. patella or knee bone) • Sesamoid bones are bones embedded in tendons. These small, round bones are commonly found in the tendons of the hands, knees, and feet. Sesamoid bones function to protect tendons from stress and wear. The patella, commonly referred to as the kneecap, is an example of a sesamoid bone. The Structure of the Skeleton The human skeletal system is generally divided into two main parts: • • The axial skeleton (80 bones) • Comprised mainly of the vertebral column (the spine), much of • the skull, and the rib cage. • Most of the body’s core muscles originate from the axial skeleton. • These core muscles help stabilize and support the axial skeleton, • thus providing proper posture and alignment. • 2) The Appendicular Skeleton - 126 Bones • The appendicular skeleton includes the movable • limbs and their supporting structures (girdles), • which play a key role in allowing us to move. • •The appendicular skeleton can be divided into • six major regions: pectoral girdle; arms and • forearms; hands; pelvis; thighs and legs; and • feet and ankles. The Skull Notes: 7 true ribs (attach to sternum directly) 3 false ribs (do not directly attach to the sternum) 2 floating ribs (do not attach to the sternum) (all attach to the vertebral column) Sternum ● ● a flat bone main function is to connect all the ribs and protect the heart Rib Cage ● ● the ribs are flat bones made up of 12 pairs of ribs BONES TO KNOW CONTINUED…. ❏ Scapula - Shoulder Blade ❏ Clavicle - Collarbone Clavicle ● ● ● a long bone more commonly known as the collar bone commonly broken when Falling On an Out-Stretched Hand (FOOT injury) • BONES TO KNOW UPPER BODY • • • • • • Humerus - upper arm Radius - lower arm (thumb side) Ulna - lower arm pinky side Carpals (wrist) Metacarpals Phalanges (fingers) BONES TO KNOW - PELVIS ❏ ❏ ❏ ❏ ❏ ❏ Ilium Ischium Pubis Sacrum Coccyx Symphysis pubis Would the pelvis be larger on a female or male? BONES TO KNOW ❏ Femur - upper leg bone • BONES TO KNOW • Tibia - larger lower leg bone • Fibula - smaller lower leg bone • Patella - knee cap Bones to know foot Bones to know foot • • • • • • • • Calcaneus Cuboid Phalanges Talus Tarsals Navicular Cuneiform Metatarsals Joints Classification: they are classified according to their structure (what they are made of) or function (type of and extent of movement allowed) • 3 main types of joints • Fibrous • Cartilaginous • Synovial • Fibrous Joints • Bound by connective tissue and allow no movement. • Found in the sutures of the skull. • (after birth all suture joints become immobile) Cartilaginous Joints (“Amphiarthroses) • The body of one bone connects to the body of another by means of cartilage. • Slight movement is possible. • For example: the intervertebral discs of the spinal column Synovial Joints (Most Joints – Diarthroses) • Synovial joints permit movement between bones. • Covered with a membrane that secretes a fluid lubricant so the joint moves more easily. • Example: Shoulder Joint Subcategories of Synovial Joints • Ball-and-socket (spheroidal) joints. The “ball” at one bone fits into the “socket” of another, allowing movement around three axes (e.g., the humerus rests in the glenoid cavity). • Gliding (or plane or arthrodial) joints. This type connects flat or slightly curved bone surfaces that glide against one another (e.g., between the tarsals and among the carpals). • Hinge (ginglymus) joints. A convex portion of one bone fits into a concave portion of another (movement in one plane). The joint between the ulna and the humerus is an example. • Pivot (or trochoid) joints. A rounded point of one bone fits into a groove of another (e.g., the joint between the first two vertebrae in the neck, which allows the rotation of the head). Saddle joints. Saddle joints allow movement in two planes (but not rotation like a ball-and-socket joint). A key saddle joint is found at the carpo- metacarpal articulation of the thumb. • Ellipsoid joints. This type of synovial joint also allows movement in two planes. The wrist is an example of an ellipsoid joint. • Joint-Related Injuries and Disease • Dislocations and Separations Dislocations: A dislocation occurs when a bone is displaced from its joint. Dislocations are often caused by collisions or falls and are common in finger and shoulder joints. • • Separations: A separation is more serious than a dislocation. In a shoulder separation, the ligaments attaching the collarbone (clavicle) and shoulder blade (scapula) are disrupted. Diseases and Disorders of The Skeletal System Osteoarthritis: is a condition involving loss of cartilage at joints. Osteoarthritis (a joint disease) is often confused with osteoporosis Osteoporosis: (bone disease) is a softening of bones due to lack of calcium. This results in a loss of bone density and easily broken bones. • Osteomyelitis: • Caused by bacteria in the bone tissue • Infection of the bone that spreads rapidly • Severe pain and at the end of the bone, and bone damage if left untreated • Herniated Disk • Sometimes called a slipped or ruptured disc • When one or more of the spinal discs balloon out from the inside the bony part of the vertebrae • If large enough can press on a nerve and cause severe pain • Carpal Tunnel • Caused by overuse of the wrist • More common in people who use keyboards often, assembly line workers, and people who play sports like racquetball. • Symptoms include – weakness and numbness in the hand, pain in wrist or elbow. • Rotator cuff tears usually involve one or all four muscles that make up the rotator cuff at the shoulder joint: supraspinatus, infraspinatus, teres minor, and subscapularis. • These muscles share a common tendinous insertion on the greater tubercle of the humerus. Thus, when a part of the tendon is torn, all muscles around the joint are affected. • The severity of a rotator cuff tear must be diagnosed by a doctor. Scoliosis • Side to side curvature of the spine Please Answer the following… • Select a joint that is prone to injury. Explain the type of joint (e.g. ball and socket, etc.), name of the injury, who is most prone to this type of injury, and basic treatment. The Muscular System Learning Goals: • We are learning about the components and functions of the musculoskeletal system • I will be able to determine the role of the MSK system in the body and determine HOW the function and structure of bones and muscles interact and work with each other • I will be able to name, label and explain the function of the components • We are learning about the major muscles of the human body • I will be able to name, label and explain the function of the major muscles in the human body Types of Muscle Tissue Below are diagrams and electron micrographs of each type of muscle tissue, differentiated by structure and function: a. smooth muscle b. cardiac muscle c. skeletal muscle. • TYPES OF MUSCLE TISSUE Muscle tissue refers to a collection of cells that shorten during contraction. • • Smooth Muscles: • Surrounding the body’s internal organs, including the blood vessels, hair follicles, and the urinary, genital, and digestive tracts, are smooth muscles. Smooth muscle tissue contracts more slowly than skeletal muscles but can remain contracted for longer periods of time. They are also involuntary. • Cardiac Muscles. • As the name suggests, cardiac muscles are found in only one place in the body—the heart. • responsible for creating the action that pumps blood from the heart to the rest of the body. Cardiac muscles are involuntary muscles because they are not controlled consciously and are instead directed to act by the autonomic nervous system. • • • • Skeletal Muscles: • These muscles are the type of muscles that are attached to the bones (by tendons and other tissues). They are the most prevalent muscle type in the human body—they comprise 30 to 40 percent of human body weight. Skeletal muscles are “voluntary”— humans have conscious control over their skeletal muscles; that is, the brain can tell them what to do. Skeletal muscle tissue is referred to as striated, or striped, • Because of its appearance under a microscope as a series of alternating light and dark stripes. (as seen on the left) The Musculoskeletal System The musculoskeletal system supports the body, keeps it upright, allows movement, and protects vital organs. The skeleton also serves as the main storage system for calcium, phosphorus, and components of blood. • • The musculoskeletal system is made up of: • The body’s bones, skeletal muscles, and connective tissue that binds them together. • Skeletal muscle fibre connects to bones directly through tough tissue fibres, called tendons. • The bones themselves are bound tightly together with other bones through ligaments. • Cartilage tissue at the ends of bones prevents the bones from grinding against one another. How are Skeletal Muscles Named? Muscles are typically named after their action, location, shape, direction of the fibres, number of divisions/heads, or the points of attachment. • The name of a muscle is frequently a clue to some important anatomical or functional characteristic of the muscle. Muscles are named according to: • Location: • Tibialis posterior – a muscle in the lower part of the leg on the back (tibia) • Tibialis anterior – a muscle in the lower part of the leg on the back (tibia) • Divisions: • biceps muscle has two heads of origin • triceps has three • quadriceps has four. • Action: • Muscles are given names according to the role they play in movement. The addition of flexor, extensor, pronator to the name of the muscle indicates its action. • Flexors: muscles that bend limbs at a joint • Extensors: muscles that straighten a limb at a joint • Adductors: muscles that move limbs toward the midline of the body • Abductors: muscles that move limbs away from the midline of the body • Pronator: muscles that rotate the wrist • Attachment: • Many muscles are named for their skeletal points of origin and insertion. • The sternocleidomastoid muscle indicates its attachment to the sternum, clavicle and mastoid process. • The subscapularis muscle is under the scapula • Shape: • Names are often based on Greek terms • deltoid • a triangular shaped muscle in the upper arm similar to the Greek letter delta • Other: • Frequently several of these factors are combined in the naming of a muscle. • The flexor digitorum superficialis is a muscle that flexes the fingers. It is found in the area of the forearm that is superficial to the flexor digitorum profundus. Anterior Muscles Posterior Muscles Agonist and Antagonist Muscle Pairs • Muscles pull. They never push. Skeletal muscles are typically arranged as opposing pairs. • The muscle primarily responsible for movement of a body part is referred to as the agonist muscle. • The muscle that counteracts the agonist, lengthening when the agonist muscle contracts, is called the antagonist muscle. • When skeletal muscle contracts, it causes movement of the attached bones. The point where the muscle attaches to the more stationary of the bones of the axial skeleton is known as the origin. Muscle Origins and Insertions The other end, the point where the muscle attaches to the bone that is moved most, is known as the insertion. For example, when you contract your biceps, you pull your forearm towards your shoulder, so you are pulling towards the origin. The insertion is on one of the bones of the forearm (the radius), called the radial tuberosity, and it is the forearm that moves during contraction. Muscles of the Neck (Lateral View) • Sternocleidomastoid • flexes head from side to side and rotates it. • Splenius • rotates the head and neck Deep Muscles of the Back (Posterior View) • Erector Spinae Group • consists of • a) spinalis • b) longissimus • c) iliocostalis • These muscles extend and laterally flex the spine. The longissimus also flexes the head. Anterior Thoracic Wall Muscles of the Thoracic • There are 3 main groups of muscles affecting the rib cage and regulating the process of breathing. • Diaphragm: • separates the thoracic cavity from the abdominal cavity. When the diaphragm contracts, air is drawn in. • Intercostal muscles • located between the ribs. They keep the ribs elevated and depress during expiration/inspiration. • Transverse Abdomininis • provides stability Abdominal Wall (Lateral View) • Rectus Abdominis • “abs” flex the trunk • External Oblique (also known as “boxer abs”) • flex and rotate the vertebral column • Think – why might these abs be more apparent in boxers? • What would be larger in a rower? Upper Limb Muscles (Anterior & Posterior) Pectoralis Major (anterior) - thick muscle covering most of the front of the chest. Internal rotation, adduction and flexion of the arm. Latissimus dorsi (posterior) makes approx. ¼ of the back “lats” It adducts, extends and internal Muscles of the Rotator Cuff (4 muscles that extend from the scapula to teh humerus and wrap around the shoulder joint) S.I.T.S. “Sit on the shoulder girdle” (Supraspinatus, Infraspinatus, Teres Minor, Subscapularis) Muscles of the Scapula (Posterior View) Supraspinatus, Infraspinatus, Teres Minor stabilize the shoulder joint. Supraspinatus abducts the shoulder, Infraspinatus and teres minor laterally rotate the shoulder. Subscapularis - rotates the humerus medially and stabilizes the shoulder. Trapezius - Scapular elevation, adduction, retraction and upward rotation and depression. It also extends the neck. Rhomboid Major and Minor - assist the trapezius in the downward rotation of the scapula and adduction and retraction of the scapula. Levator Scapulae - elevates the scapula, rotates the scapula downwards. Scapular Muscles that Move the Humerus. Deltoid Deltoid - 3 heads - anterior head flexes and medially rotates the shoulder joint, the lateral head abducts the arm, the posterior head extends and laterally rotates the arm. Teres Major Teres Major - medial rotator, adductor, extends the humerus at the shoulder joint. Muscles of the Scapula (Anterior View) Biceps Brachii supinates the forearm and flexes the the elbow. Triceps Brachii - arm extensor. Muscles of the Forearm Muscles of the Hip Gluteus Maximus - hip extension and external rotation. Gluteus Medius - adduction and internal rotation of the thigh. Gluteus Minimus - abduction and internal rotation of the thigh. Sartorius - flexion and outward rotation of the hip and it helps to flex the knee. Iliopsoas - hip flexion Psoas minor - present in 40% of the population, weak trunk flexor Adductor longus, magnus, brevis - hip adduction Gracilis - adducts the hip and flexes the knee. Muscles of the Thigh Quadriceps Group - Rectus femoris - knee extension and hip flexion, Vastus lateralis, Vastus Intermedius and Vastus Medialis - These 3 muscles are responsible for knee extension. Hamstrings - Biceps femoris extensor of the hip and flexor of the knee and externally rotate the flexed knee. Semimembranosus - flexes the knee, rotates it inward and extends the hip. Semitendinosus - flexes and laterally rotates the knee and extends the hip. Extrinsic Muscles of the Foot Tibialis anterior dorsiflexes the ankle and inverts the foot. Gastrocnemius plantar flexes the ankle and flexes the knee. Soleus - plantar flexes the ankle. Tibialis Posterior plantar flexes the ankle and inverts the foot.
