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HUMAN BODY •Climbing the walls? Spiderman is able to climb walls •The explanation: 1.Hairs (called setae) on gecko’s toes contain split ends (called spatulae) 2. ability to “stick” to surfaces from attractions between molecules on the spatulae and the surface on which the gecko is crawling – Correlation between structure and function – Human structure has a hierarchy: • • • • Cell Tissues Organs Organ sytems TISSUES • groups of cells with a common structure and function • Main types: – Epithelial – Connective – Muscle – Nervous Epithelial tissue • sheets of closely packed cells • covers the body and lines the cavities and tubes of internal organs • Functions in protection, secretion, and exchange A Simple squamous epithelium (lining the air sacs of the lung) D Stratified squamous epithelium (lining the esophagus) B Simple cuboidal epithelium (forming a tube in the kidney) Layers of dead cells Rapidly dividing epithelial cells C Simple columnar epithelium (lining the intestine) E Stratified squamous epithelium (human skin) Connective tissue • binds and supports other tissues • various types • characterized by sparse cells in an extracellular gel matrix Fat droplets Cartilageforming cells C. Adipose tissue Matrix Cell nucleus D. Cartilage (at the end of a bone) Collagen fibers Central canal B. Fibrous connective tissue (forming a tendon) Cell Collagen fiber White blood cells Matrix Red blood cell Boneforming cells E. Bone Plasma A. Loose connective tissue (under the skin) F.Blood Muscle tissue • functions in movement • Types: – Skeletal muscle is responsible for voluntary body movements – Cardiac muscle pumps blood – Smooth muscle moves the walls of internal organs such as the stomach Unit of muscle contraction Muscle fiber Muscl e fiber Junction between two cells Nucleus Nucleus Muscle fiber Nucleus B Cardiac muscle A Skeletal muscle C Smooth muscle Nervous tissue • forms a communication network • the branching neurons transmit nerve signals that help control body activities Cell body Nucleus LM 330 Cell extensions • Artificial tissues have medical uses: can assist in the healing of several injuries ORGANS – Each organ is made of several tissues – collectively perform specific functions Lumen Small intestine (cut open) Lumen Epithelial tissue (columnar epithelium) Connective tissue Smooth muscle tissue (2 layers) Connective tissue Epithelial tissue ORGAN SYSTEMS • Organ systems work together to perform life functions 1. Digestive 2. Respiratory 3. Circulatory 4. Lymphatic 5. Immune 6. excretory 7. Endocrine 8. integumentary 9. Skeletal 10.Muscular 11.reproductive – digestive and respiratory systems: • gather food and oxygen Nasal cavity Larynx Mouth Trachea Esophagus Liver Bronchus Stomach Lung Small intestine Large intestine Anus A Digestive system B Respiratory system – The circulatory system, aided by the lymphatic system • Transports the food and oxygen – The immune system • Protects the body from infection and cancer Bone marrow Heart D Immune system Thymus Spleen E Lymphatic system Blood vessels C Circulatory system Lymph nodes Lymph vessels – The excretory system • Disposes of certain wastes – The endocrine and nervous systems • Control body functions Pituitary gland F Excretory system Kidney Thyroid gland Thymus Adrenal gland Ureter Urinary bladder Pancreas Testis (male) Urethra Ovary (female) G Endocrine system – The integumentary system • Covers and protects the body – Skeletal and muscular systems • Support and move the body Hair Cartilage Skin Nails I Integumentary system Skeletal muscles Bones J Skeletal system K Muscular system – The reproductive system • Perpetuates the species Male Female Prostate gland Vas deferens Oviduct Ovary Urethra Penis Uterus Vagina Testis L Reproductive systems New imaging technology • reveals the inner body without surgery • X-rays: used for imaging bones and teeth • MRI, Magnetic resonance imaging: visualization of soft tissues • MRM, Magnetic resonance microscopy: 3-D images of very small structures • CT, Computed tomography scans: excellent diagnostic tools • PET, Positron-emission tomography: Yields information about metabolic processes at specific locations in the body Skull SKELETON Examples of joints 1 Shoulder girdle Clavicle Scapula Sternum • human skeleton: 206 bones – axial skeleton: • Skull • Backbone • rib cage – appendicular skeleton: Ribs 2 Humerus 3 Vertebra Radius Ulna Pelvic girdle Carpals Phalanges Metacarpals Femur • bones of the arms and legsPatella • and the joints where they Tibia attach to the axial skeleton Fibula – pectoral or shoulder joint – pelvic or hip joint Tarsals Metatarsals Phalanges – Movable joints • Provide the human skeleton with flexibility Head of humerus Humerus Scapula Ulna Ulna Radius 1 Ball-and-socket joint 2 Hinge joint 3 Pivot joint • Bones are complex living organs: – Cartilage at the ends of bones: Cushions the joints - Bone cells, serviced by blood vessels and nerves • Live in a matrix of flexible protein fibers and hard calcium salts – Long bones have a central cavity: to store yellow bone marrow, which is mostly stored fat – Spongy bone contains red marrow: blood cells are made Cartilage Spongy bone (red bone marrow) Compact bone Central cavity Yellow bone marrow Fibrous connective tissue Blood vessels Cartilage • Broken bones can heal themselves: re realigned and immobilized – Artificial joints: often used to repair severe injuries • Weak, brittle bones are a serious health problem, even in young people • Osteoporosis, a bone disease characterized by weak, porous bones • dynamic bone “remodeling” model: going on all the time: – osteoblasts deposit bone – osteoclasts break bone and release calcium – As a person ages, the backbone and other bones tend to decline in mass; excessive bone loss is called osteoporosis •The skeleton and muscles interact in movement: Biceps contracted, triceps relaxed (extended) Triceps contracted, biceps relaxed Biceps Triceps Tendon Biceps Triceps • Muscle cells are the motors of the body • contractible proteins fibers, myofilaments • with the proteins actin and myosin MUSCLES Levels of Functional Organization in a Skeletal Muscle Fiber Muscle Fascicle Muscle Fiber Myofibril Sacromere Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings 3 types: • Smooth muscle: walls of blood vessels and the gut • Skeletal muscle: move the bones of the skeleton • Cardiac muscle: fibers that branch and interconnect to form a network connected, electrical impulses passes from cell to cell causing the heart to contract in an orderly fashion • Skeletal muscles move the bones • Tendons: connective tissue that attach muscles to bone • Muscle tone: Even at rest, some of the motor units of muscles are always contracting= resting tension • Athletic training increases strength and endurance: causes increases in: - number of mitochondria - concentration of glycolytic enzymes - glycogen reserves - myofibrils Types of sports fast or white fibers: • Large in diameter-densely packed myofibrils Slow or red fibers: • Only 1/2 the diameter of fast fibers • Large glycogen reserves • few mitochondria • Takes 3 times longer to contract after stimulation • Can contract in 0.01 sec following stimulation • abundant mitochondria • uses a lot of ATP • uses anerobic glycolysis: converts stored glycogen to lactic acid • fatigue rapidly because glycogen reserves are limited and lactic acid builds up • Uses aerobic metabolism • Has a more extensive capillary network • Red color due to red pigment of myoglobin • Muscles only pull because myofibrils contract: – muscles in the joints are attached in opposing pairs called flexors and extensors – when contracted they move the bones in different directions • sliding filament model: muscular contraction – the head of a myosin filament binds to an actin filament – ATP is used to flex the myosin head – when the muscle contracts, the myosin head returns to its original shape and pulls the actin it is attached to along with it