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Tissues of the skin epidermis- squamous epithelium; basement membrane dermis- largely connective tissue; many nerves and blood vessels; smooth muscle hypodermis (NOT part of skin) - adipose tissue and more loose connective tissue Roles •protection •maintenance of body temperature •storage of fat •synthesis of vitamin D •excretion of salts, water and wastes in sweat •sensory perception Accessory structures Hair Follicle - Originate in epidermis, extend into dermis; muscle attached Hair is pigmented; determined by amount of melanin, pigment production decreases with age Two types of exocrine glands Sebaceous- sebum (oil, wax) associated with hair follicles helps maintain pliability of skin Sweat glands apocrine (armpits, groin) Melanin • • • • • Protects against UV Use UV -> VitaminD One hour/week Protects DNA More UV -> more melanin -> tan Nails Nail bed overlaid by nail plate Nail growth originates from root; cells become keratinized The Skeletal System Parts of the skeletal system Bones (skeleton) Joints Cartilages Ligaments (bone to bone)(tendon=bone to muscle) Divided into two divisions Axial skeleton Appendicular skeleton – limbs and girdle a. Axial: skull, backbone, ribs, sternum a. Appendicular: arms, legs, shoulders, hips,wrists, ankles Classification of Bones on the Basis of Shape The Skull Two sets of bones Cranium Facial bones Bones are joined by sutures Only the mandible is attached by a freely movable joint Slide The Vertebral Column Vertebrae separated by intervertebral discs The spine has a normal curvature Each vertebrae is given a name according to its location Slide 5.28 The Bony Thorax Forms a cage to protect major organs Made-up of three parts Sternum Ribs Thoracic vertebrae Figure 5.19a Slide The Pectoral (Shoulder) Girdle Composed of two bones Clavicle – collarbone Scapula – shoulder blade Slide 5.33 Bones of the Upper Limb The arm is formed by a single bone Humerus Figure 5.21a, b Slide Bones of the Upper Limb • The forearm has two bones • Ulna • Radius Figure 5.21c Slide Bones of the Upper Limb The hand Carpals – wrist Metacarpals – palm Phalanges – fingers Figure 5.22 Slide 5.36 Bones of the Lower Limbs The thigh has one bone Femur – thigh bone Slide Bones of the Lower Limbs The leg has two bones Tibia Fibula Slide Bones of the Lower Limbs The foot Tarsus – ankle Metatarsals – sole Phalanges – toes Figure 5.25 BONE FRACTURES A break in a bone Types of bone fractures Closed (simple) fracture – break that does not penetrate the skin Open (compound) fracture – broken bone penetrates through the skin Bone fractures are treated by reduction and immobilization Realignment of the bone Types of joints • Gliding joints, the articulating surfaces are typically flat • Hinge joints, found in the fingers and elbow; the spoon-like surface fits into a concave surface • Ball and socket, shoulder joint; where a ball fits into a cuplike depression • Pivot joints, found between the proximal ends of the radius and ulna; surface fits Joint Damage: Arthritis Muscular System • Muscles are responsible for all types of body movement • Your body has more than 600 muscles • Three basic muscle types – Skeletal muscle – Cardiac muscle – Smooth muscle Skeletal Muscle Characteristics • Most are attached by tendons to bones • Cells are multinucleate • Striated – have visible banding • Voluntary – subject to conscious control Functions of Skeletal Muscle – – – – Produce movement Maintain posture Stabilize joints Generate heat • Sites of muscle attachment – Bones – Cartilages – Connective tissue coverings Action of Skeletal Muscle – Muscles do work only by contracting – In order for muscles to cause any kind of movement, they must work in pairs – When one contracts, the other relaxes Smooth Muscle • Help control breathing, blood pressure, and the movements of the digestive system • Has no bands - hence the name Characteristics of Smooth Muscle • • • • Has no striations Spindle-shaped cells Single nucleus Involuntary – no conscious control • Found mainly in the walls of hollow organs Cardiac Muscle – Found only in the heart • Branches out in many directions, weaving a complex mesh • Contractions of cardiac muscle cause the heart to beat Cardiac Muscle Characteristics • Has striations • Usually has a single nucleus • Joined to another muscle cell at an intercalated disc • Involuntary • Found only in the heart Naming Skeletal Muscle – by Location – Structure near which a muscle is found – Muscle near frontal bone = Frontalis – Muscle near the Tibia = Tibialis anterior Naming Skeletal Muscle – by Size – MAXIMUS means largest • Gluteus Maximus – MINIMUS means smallest • Gluteus Minimus – LONGUS means longest • Fibularis Longus – BREVIS means short • Fibularis Brevis – TERTIUS means shortest • Fibularis Tertius Naming Skeletal Muscle - by number of Origins • Number of tendons of origin – BICEPS means two • Biceps Brachii – TRICEPS means three • Triceps Brachii – QUADRICEPS means four • Quadriceps Femoris