Tissues and Structures Lecture Slides PDF

TISSUESAND STRUCTURES DEFINITION OF TISSUE A groups of similar cells, usually having similar embryonic origin and specialized function Four general types Epithelial Connective...

TISSUESAND STRUCTURES DEFINITION OF TISSUE A groups of similar cells, usually having similar embryonic origin and specialized function Four general types Epithelial Connective Muscle Nervous  DEVELOPMENT Tissues develop from separation of germinal layers in early development From Germ Layers Three layers – Ectoderm – Mesoderm – Endoderm Epithelia develop from all three layers Connective and muscle tissue from mesoderm Nervous tissue from ectoderm  EPITHELIAL TISSUE Forms superficial layer of skin & some internal organs, inner lining Of blood vessels, duct, & body cavities, and interiors of respiratory, digestive, urinary and reproductive organs Characteristics: – Closely packed together – Arranged in continuous sheets of one or more layers  TWO GENERAL TYPES – Covering and lining epithelium – Glandular epithelium  COVERING AND LINING EPITHELIUM Classified based on arrangement of layers and shape – Layers: simple, stratified, pseudostratified – Shapes: squamous, cuboidal, columnar, transitional  GLANDULAR EPITHELIUM Mass of cells adapted for secretion into ducts, onto a surface or into blood Two types – Endocrine (ductless) - secretory products released to extracellular space – Exocrine: - secrete products directly into ducts  CONNECTIVE TISSUE Most widespread tissue in body Binds together, supports and strengthens other tissues, protects & insulates internal organs and compartmentalizes structures (e.g. skeletal muscles) Blood & lymph responsible for transport Adipose tissue stores energy and insulates CONNECTIVE TISSUE CELLS Fibroblasts - most abundant type and found in all connective tissues – Important contributors to ground substance and fibers Macrophages - fixed or wandering, phagocytic Plasma cells - mature B-lymphocytes producing antibodies Mast cells - histamine producing cells near blood vessels Adipocytes - lipid storage WBC’s  TYPES OF CONNECTIVE TISSUE Loose (Areolar) connective tissue (serous and synovial membranes are formed by this tissue) – Adipose ( white and brown adipose tissue) – Reticular Dense connective tissue (fibrous, elastic tissue) Cartilage (hyaline, elastic fibrocartilage, fibrocartilage) Bone Liquid connective tissue-Blood & lymph  MUSCLE TISSUE Provides motion, maintenance of posture, and heat production Three types – Skeletal: attached to bones, striated, voluntary – Cardiac: heart wall, striated, involuntary – Smooth: walls of hollow structures, not striated, involuntary N ERVOUS TISSUE Quickly communicate between parts of the body, sensitive to stimuli, interpret information, coordinate action Two types – Neurons: generate and conduct electrical impulses – Neuroglia: provide protection and support for neurons ORGAN SYSTEMS ORGAN SYSTEMS  INTEGUMENTARY SYSTEM Skin, hair, nails, sweat glands, mammary glands, enamel of teeth An extensive sensory organ Forms the body’s protective cover SKELETAL SYSTEM Consists of bones and cartilage Fxn: provide basic shape and support for body and muscle action. Also protects vital organs  ARTICULAR SYSTEM Consists of joints and ligaments Fxn: connects bony parts of skeleton, provides site of movement  MUSCULAR SYSTEM Consists: skeletal, smooth, cardiac muscle  NERVOUS SYSTEM Consists of central nervous system and peripheral nervous system. Sense organs: ophthalmic, olfactory, hearing and balance, gustatory included Fxn: controls and co-ordinates the functions of the organ systems  CIRCULATORY SYSTEM Consists: Cardiovascular- heart and blood vessels Fxn: conduct blood to the body Lymphatic- network of lymphatic vessels Fxn: filters excess tissue fluid  RESPIRATORY SYSTEM Consists: air passages and lungs Fxn: Supply oxygen to blood and eliminates carbon dioxide  DIGESTIVE/ALIMENTARY Consists of digestive tract from mo ut h anus, associated glands and organs Fxn: Ingesting of food, elimination of waste products  ENDOCRINE SYSTEM System of ductless glands Regulates body functions via hormones secreted into the bloodstream. Hormones influence metabolism, growth, reproduction etc…  URINARY SYSTEM Consists: kidneys, urinary bladder, ureters, urethra Fxn: filters blood and excretes urine ( liquid waste)  GEN ITAL SYSTEM Consists of gonads(ovaries, testes), ducts and genitalia Female reproductive tract nourishes and delivers foetus  NB None of the organs systems work in isolation Eg. The skeletal, articular, muscular work together to produce locomotion. And other organ systems eg. Circulatory and nervous system involved indirectly  INTEGUMENTARY SYSTEM The skin is the largest body organ Provides protection, heat regulation, sensation, synthesis and storage of Vitamin D Consists of a dermis and epidermis  The skin Epidermis: tough superficial layer which has sensory nerve endings sensitive pain, tempreture, touch Dermis: dense layer of collagen and elastic fibers  THE SKIN Contains specialised structures: Hair follicles Musculi arector pili Sebaceous glands Sweat glands Between the skin and deep fascia is the subcutaneous tissue  THE SKIN The subcutaneous tissue ( superficial fascia ) contains: Sweat glands Superficial blood vessels, cutaneous nerves, lymphatics, stored fat INTEGUMENTARY SYSTEM Superficial fascia lies between the dermis and overlying deep fascia Its composed of loose connective tissue, fat, superficial blood vessels, lymphatics and nerves It provides most of the body’s fat storage. The thickness of this superficial fascia varies in INTEGUMENTARY SYSTEM Deep fascia is dense connective tissue, devoid of fat. It covers the muscles In the limbs it may cover groups of muscles- fascial compartments Sheets of deep fascia may separate fascial compartments- intermuscular septa SKELETAL SYSTEM Consist of the Axial Skeleton: Cranium/skull Vertebral column including hyoid bone Thoracic cage( ribs, sternum) Appendicular skeleton: Bones of the limbs including pectoral and shoulder girdle  AXIAL SKELETON vertebra Cranium APPENDICULAR SKELETON  FUNCTIONS Bones are rigid organs are the endoskeleton of most vertebrates. Support and protect the various organs of the body Produce red and white blood cells and store minerals. Red bone marrow produces red blood cells, most fetal bones consists of red bone marrow, some adult bones like sternum, hip bone, ribs, vertebrae, skull, ends of arm and thigh bones. Provides support and movement via attachments for soft tissue and muscle Plays a role in the metabolism of minerals such as calcium and phosphorus. 99% Ca produce by bone SKELETAL SYSTEM Skeleton composed of bone and cartilage Bones at a synovial joint are covered by hyaline cartilage Providing low friction, smooth ,free movement  SKELETAL SYSTEM At birth, there are over 270 bones in an infant human's body, but many of these fuse together as the child grows, leaving a total of 206 separate bones in a typical adult, not counting sesamoid bones and ossicles. The largest bone in the human body is the femur and the smallest bone is the stapes BONE STRUCTURE Diaphysis Epiphysis Metaphysis: contains epiphyseal growth plate Articular cartilage Periosteum Medullary cavity- contains fatty yellow bone marrow in adults Endosteum  BLOOD SUPPLY OF BONE Centre of diaphysis is the nutrient foramen- nutrient artery Classification of bone according to shape There are five types of bones in the human body: long, short, flat, irregular, and sesamoid.  BONES Long bones : have shaft, the diaphysis, that is much longer than it is wide. Most bones of the limbs. Short bones: roughly cube -shaped, and have only a thin layer of compact bone surrounding a spongy interior. The bones of the wrist and ankle are short bones Flat bones : thin and generally curved, with two parallel layers of compact bones sandwiching a layer of spongy bone. Most of the bones of the skull, sternum are flat bones Sesamoid bones: embedded in tendons. Since they act to hold the tendon further away from the joint, the angle of the tendon is increased and thus the leverage of the muscle is increased. Examples of sesamoid bones are the patella and pisiform Irregular bones :They consist of thin layers of compact bone surrounding a spongy interior. The bones of the spine, pelvis , and some bones of the skull  THE SKULL In some bones, such as the flat bones of theskull, mesenchymedifferentiatesdirectly into bone, a processknown as intramembranous ossification At birth, the sutures are wide and are called fontanelles. The most prominent of these is the anterior fontanelle. Sutures and fontanelles allow the bones of the skull to overlap (molding) during birth  THE LIMBS In most bones, however,mesenchymal cells first give rise to hyaline cartilage models, which in turn becomeossified by endochondral ossification. JOINTS Unions/junctions between two or more bones Some joints have no movement: epiphyseal plates of growing bones Slight movement: teeth within sockets Freely movable: shoulder joint  CLASSIFICATION OF JOINTS Synovial joints: united by a joint capsule, containing synovial fluid Fibrous joints: united by fibrous tissue likes the sutures of a skull Cartilaginous joints: united by hyaline cartilage or fibrocartilage like the joints between vertebrae TYPES SYNOVIAL JOINTS Plane Hinge Saddle Condyloid Pivot Ball and socket  MUSCULAR SYSTEM: TYPES OF MUSCLE 1. SKELETAL – named for its location – attached to bones and moves the skeleton. striated (has light & dark bands under a microscope) voluntary – under conscious control 2. CARDIAC – forms wall of heart (striated but involuntary) 3. SMOOTH – located in walls of internal hollow organs eg. Blood vessels, GIT (non striated and involuntary)  MUSCLES CAN BE DESCRIBED ACCORDING TO SHAPE EFFECTS THE MUSCLE’S POWER AND RANGE OF MOTION Flat Pennate Fusiform Quadrate Circular Multi-headed or bellied TYPES OF MUSCLE Involuntary muscle Voluntary muscle  INVOLUNTARY MUSCLE CARDIAC MUSCLE Muscles are striated. Arrangement is similar to skeletal muscle. However, Junctions between cells = intercalated discs. This is unique to cardiac muscle make up the wall of the heart. ANS regulates does not initiate muscles which contract spontaneously. The alternating contraction and relaxation of the heart muscle is not consciously controlled. Rather the heart beats because it has a pacemaker that initiates its own contraction.  VISCERAL (SMOOTH) MUSCLE BLADDER- SMOOTH MUSCLE IN ITS WALL= DETRUSOR No striations. Walls of viscera – GASTROINTESTINAL TRACT, BLADDER, RENAL Slow, sustained, SYSTEM, RESPIRATORY rhythmic TRACT, REPRODUCTIVE contraction not SYSTEM. under voluntary control.  CIRCULATORY SYSTEM Through this system the heart pumps blood through the body  CIRCULATORY SYSTEM Divided into two components: pulmonary and systemic circulation Three types of blood vessels: arteries, veins, capillaries PULMONARYVEINS SVC LEFT ATRIUM AORTA AORTA RIGHT ATRIUM PULMONARY RIGHT ATRIUM TRUNK LEFT VENTRICLE RIGHT VENTRICLE  NERVOUS SYSTEM CEREBRUM BRAIN CEREBELLUM CENTRAL Midbrain BRAIN STEM NERVOUS Pons Medulla SYSTEM SPINAL CORD NERVOUS SYSTEM CRANIAL NERVES PERIPHERAL NERVOUS SYSTEM SPINAL NERVES HOW IS THE NS STRUCTURALLY ORGANIZED? HOW IS THE NS FUNCTIONALLY ORGANIZED? SOMATIC SENSORY (conscious) SOMATIC NERVOUS SYSTEM SOMATIC MOTOR (voluntary, skm) NERVOUS SYSTEM SENSORY (unconscious) SYMPATHETIC SYSTEM MOTOR AUTONOMIC (involuntary:smf, glands) NERVOUS SYSTEM PARASYMPATHETIC SYSTEM VISCEROMOTOR (involuntary: smf,glands)  BRAIN CNS Cerebrum Cerebellum Brain stem Midbrain Pons Medulla SPINAL CORD 31-33 SPINAL NERVE PAIRS 12 CRANIAL NERVE PAIRS BRAIN WITH CRANIAL NERVES FORMATION OF SPINAL NERVES AUTONOMIC NEVOUS SYSTEM  DIGESTIVE SYSTEM: THE BOWEL/ THE INTESTINES Small Intestine: duodenum, jejunum, ileum Large Intestine: Ascending, Descending, Transverse Colon, caecum, appendix, rectum THE PANCREAS  THE LIVER Functions: filtering bacteria and toxins from blood, creating energy from carbohydrates, proteins and fats, manufacturing bile It is sheltered by the rib cage, found lying close to diaphragm and stomach  ENDOCRINE SYSTEM Major Endocrine Glands: Hypothalamus Pituitary Gland Thyroid Gland Parathyroid Gland Thymus  FEMALE REPRODUCTIVE ORGANS Layman’s language = womb Protects, provides nutrition to fertilized ovum enabling it to grow into fully formed fetus During parturition contractions of muscular walls result in expulsion of fetus Lies between bladder and rectum  FEMALE REPRODUCTIVE ORGANS Consists of body, cervix, joining vagina inferiorly Uterine tubes project laterally from uterus and open into peritoneal cavity continuous with central canal of cervix Include : MALE REPRODUCTIVE ORGANS Testes System of ducts (epididymis, ductus deferens, ejaculatory ducts, urethra) Accessory sex glands (seminal vesicles, prostate, bulbourethral glands) Supporting structures (penis, scrotum)