Introduction and Tissues Human Anatomy BIOL 1010 Liston Campus What is Anatomy? Anatomy (= morphology): study of body’s structure Physiology: study of body’s function Structure reflects Function!!! Branches of Anatomy Gross: Large structures Surface: Landmarks Histology: Cells and Tissues Developmental: Structures change through life Embryology: Structures form and develop before birth Hierarchy of Structural Organization Each of these build upon one another to make up the next level: Chemical level Cellular Tissue Organ Organ system Organism Hierarchy of Structural Organization Chemical level Atoms combine to make molecules 4 macromolecules in the body Carbohydrates Lipids Proteins Nucleic acids Hierarchy of Structural Organization Cellular Made up of cells and cellular organelles (molecules) Cells can be eukaryotic or prokaryotic Organelles are structures within cells that perform dedicated functions (“small organs” http://cmweb.pvschools.net/~bbecke/newell/Cells.html Hierarchy of Structural Organization Tissue Collection of cells that work together to perform a specialized function 4 basic types of tissue in the human body: Epithelium Connective tissue Muscle tissue Nervous tissue www.emc.maricopa.edu Hierarchy of Structural Organization Organ Made up of tissue Heart Brain Liver Pancreas, etc…… Pg 158 Hierarchy of Structural Organization Organ system (11) Made up of a group of related organs that work together Integumentary Skeletal Muscular Nervous Endocrine Cardiovascular Lymphatic Respiratory Digestive Urinary Reproductive Circulatory Pg 314 Hierarchy of Structural Organization Organism An individual human, animal, plant, etc…… Made up all of the organ systems Work together to sustain life Anatomical Directions Anatomical position Regions Axial vs. Appendicular Anatomical Directions-It’s all Relative! Anterior (ventral) vs. Posterior (dorsal) Medial vs. Lateral Superior (cranial) vs. Inferior (caudal) Superficial vs. Deep Proximal vs. Distal Anatomical Planes Frontal = Coronal Transverse = Horizontal = Cross Section Sagittal Pg 3 Reference Point Anterior – (ventral) Closer to the front surface of the body Posterior – (dorsal) Closer to the rear surface of the body Frontal Plane Medial – Lying closer to the midline Lateral – Lying further away from the midline Sagittal Plane Superior – (cranial) Closer to the head in relation to the entire body (More General) Inferior – (caudal) Away from the head or towards the lower part of the body Horizontal Plane Superficial – Towards the surface Deep – Away from the surface Surface of body or organ Proximal – Closer to the origin of a body part (More Specific) Distal – Further away from the origin of a body part Origin of a structure Embryology: growth and development of the body before birth 38 weeks from conception to birth Prenatal period Embryonic: weeks 1-8 Fetal: weeks 9-38 Basic adult body plan shows by 2nd month Skin = epidermis, dermis Outer body wall=muscle, vertebral column and spinal cord Body cavity and digestive tubes Kidney and gonads Limbs=skin, muscle, bone Weeks 5-8 and Fetal Period Second month, tadpole person Tail disappears Head enlarges Extremities form (day 28, limb buds appear) Eyes, nose, ears form Organs in place Fetal Period Rapid growth and maturation Organs grow and increase in complexity & competence 4 Types of Tissue 1)Epithelium 2)Connective 3)Muscle 4)Nervous Tissues: groups of cells closely associated that have a similar structure and perform a related function Four types of tissue Epithelial = covering/lining Connective = support Muscle = movement Nervous = control Most organs contain all 4 types Tissue has non-living extracellular material between its cells EPITHELIAL TISSUE: sheets of cells cover a surface or line a cavity Functions Protection Secretion Slippery Surface Absorption Ion Transport Characteristics of Epithelium Cellularity Composed of cells Specialized Contacts Joined by cell junctions Polarity Apical vs. Basal surfaces differ Supported by Connective Tissue Avascular Innervated Regenerative Classification of Epithelium-based on number of layers and cell shape Layers Simple Stratified Psuedostratified Stratified layers characterized by shape of apical layer Shapes Squamous Cuboidal Columnar Transitional Types of Epithelium Simple squamous (1 layer) Lungs, blood vessels, ventral body cavity Simple cuboidal Kidney tubules, glands Simple columnar Stomach, intestines Pseudostratified columnar Respiratory passages (ciliated version) Stratified squamous (>1 layer) Epidermis, mouth, esophagus, vagina Named so according to apical cell shape Regenerate from below Deep layers cuboidal and columnar Transitional (not shown) All histology pictures property of BIOL 1010 Lab Thins when stretches Hollow urinary organs Endothelium Endothelium Simple squamous epithelium that lines vessels e.g. lymphatic & blood vessel Mesothelium Simple squamous epithelium that forms the lining of body cavities e.g. pleura, pericardium, peritoneum Features of Apical Surface of Epithelium Microvilli: (ex) in small intestine Finger-like extensions of the plasma membrane of apical epithelial cell Increase surface area for absorption Cilia: (ex) respiratory tubes Whip-like, motile extension of plasma membrane Moves mucus, etc. over epithelial surface 1-way Flagella: (ex) spermatoza Extra long cilia Moves cell www.colorado.edu/.../020digestion.htm Features of Lateral Surface of Epithelium Cells are connected to neighboring cells via: Proteins-link cells together, interdigitate Contour of cells-wavy contour fits together Cell Junctions (3 common) Desmosomes adhesive spots on lateral sides linked by proteins/filaments holds tissues together Tight Junctions at apical area plasma membrane of adjacent cells fuse, nothing passes Gap junction spot-like junction occurring anywhere made of hollow cylinders of protein lets small molecules pass Features of the Basal Surface of Epithelium Basement membrane Sheet between the epithelial and connective tissue layers Attaches epithelium to connective tissue below Made up of: Basal lamina: thin, non-cellular, supportive sheet Made of proteins Superficial layer Acts as a selective filter Assists epithelial cell regeneration by moving new cells Reticular fiber layer Deeper layer Support Glands Epithelial cells that make and secrete a product Products are water-based and usually contain proteins Classified as: Exocrine Endocrine Uni-/multicellular Page 116 Glands: epithelial cells that make and secrete a water-based substance w/proteins Exocrine Glands Secrete substance onto body surface or into body cavity Activity is local Have ducts (simple vs. compound) Unicellular (goblet cells) or Multicellular (tubular, alveolar, tubuloalveolar) (ex) salivary, mammary, pancreas, liver Glands: epithelial cells that make and secrete a water-based substance w/proteins Endocrine Glands Secrete product into blood stream Either stored in secretory cells or in follicle surrounded by secretory cells Hormones travel to target organ to increase response (excitatory) No ducts (ex) pancreas, adrenal, pituitary, thyroid 4 Types of Tissue 1)Epithelium 2)Connective 3)Muscle 4)Nervous 4 Types of Connective Tissue 1) 2) 3) 4) Connective Tissue Proper Cartilage Bone Tissue Blood Connective Tissue (CT): most abundant and diverse tissue Four Classes Functions include connecting, storing & carrying nutrients, protection, fight infection CT contains large amounts of non-living extracellular matrix Some types vascularized All CT originates from mesenchyme Embryonic connective tissue 1) Connective Tissue Proper Two kinds: Loose CT & Dense CT Prototype: Loose Areolar Tissue Underneath epithelial tissue Functions Support and bind to other tissue Hold body fluids Defends against infection Stores nutrients as fat Each function performed by different kind of fiber in tissue Fibers in Connective Tissue Fibers For Support Reticular: form networks for structure & support (ex) cover capillaries Collagen: strongest, most numerous, provide tensile strength (ex) dominant fiber in ligaments Elastic: long + thin, stretch and retain shape (ex) dominant fiber in elastic cartilage In Connective Tissue Proper Fibroblasts: cells that produce all fibers in CT produce + secrete protein subunits to make them produce ground matrix Interstitial (Tissue) Fluid derived from blood in CT proper medium for nutrients, waste + oxygen to travel to cells found in ground matrix Ground Matrix (substance): part of extra-cellular material that holds and absorbs interstitial fluid Made and secreted by fibroblasts jelly-like with sugar & protein molecules Defense from Infection Areolar tissue below epithelium is body’s first defense Cells travel to CT in blood Macrophages-eat foreign particles Plasma cells-secrete antibodies, mark molecules for destruction Mast cells-contain chemical mediators for inflammation response White Blood Cells = neutrophils, lymphocytes, eosinophils-fight infection Ground substance + cell fibers-slow invading microorganisms Specialized Loose CT Proper Adipose tissue-loaded with adipocytes, highly vascularized, high metabolic activity Insulates, produces energy, supports (eg) in hypodermis under skin Reticular CT-contains only reticular fibers Forms caverns to hold free cells (eg) bone marrow, holds blood cells Forms internal “skeleton” of some organs (eg) lymph nodes, spleen Dense/Fibrous Connective Tissue Contains more collagen Can resist extremely strong pulling forces Regular vs. Irregular Regular-fibers run same direction, parallel to pull (eg) fascia, tendons, ligaments Irregular-fibers thicker, run in different directions (eg) dermis, fibrous capsules at ends of bones Components of CT Proper Summarized Cells Matrix Fibroblasts Gel-like ground substance Defense cells Collagen fibers Reticular fibers Elastic fibers -macrophages -white blood cells Adipocytes 2) Cartilage Chondroblasts produce cartilage Chondrocytes mature cartilage cells Reside in lacunae More abundant in embryo than adult Firm, Flexible Resists compression (eg) trachea, meniscus Avascular (chondrocytes can function w/ low oxygen) NOT Innervated Perichondrium dense, irregular connective tissue around cartilage growth/repair of cartilage resists expansion during compression of cartilage Cartilage in the Body Three types: Hyaline most abundant fibrils in matrix support via flexibility/resilience (eg) at limb joints, ribs, nose Elastic many elastic fibers in matrix too great flexibility (eg) external ear, epiglottis Fibrocartilage resists both compression and tension (eg) meniscus, annulus fibrosus Components of Cartilage Summarized Cells Matrix Chondrocytes Gel-like ground substance Chondroblasts Lots of water (in growing cartilage) Some have collagen and elastic fibers Histology of Cartilage Hyaline Cartilage Histology of Cartilage Elastic Cartilage Histology of Cartilage Fibrocartilage www.indigo.com/software/gphpcd/his49-52.html 3) Bone Tissue:(a bone is an organ) Well-vascularized Function: support (eg) pelvic bowl, legs protect (eg) skull, vertebrae mineral storage (eg) calcium, phosphate (inorganic component) movement (eg) walk, grasp objects blood-cell formation (eg) red bone marrow Bone Tissue Osteoblasts Secrete organic part of bone matrix Osteocytes Mature bone cells Maintain bone matrix Osteoclasts Degrade and reabsorb bone Periosteum External layer of CT that surrounds bone (except at joints) Endosteum Internal layer of CT that lines cavities and covers trabeculae academic.kellogg.cc.mi.us/.../skeletal.htm Compact Bone External layer Osteon (Haversian system) Parallel to the long axis of the bone Groups of concentric tubules (lamella) Lamella = layer of bone matrix where all fibers run in the same direction Adjacent lamella fibers run in opposite directions Haversian Canal runs thru center of osteon Contains BV and nerves www.mc.vanderbilt.edu/.../CartilageandBone03.htm Bone Anatomy: Spongy bone Spongy bone (cancellous bone): internal layer Trabeculae: small, needle-like pieces of bone form honeycomb each made of several layers of lamellae + osteocytes no canal for vessels space filled with bone marrow not as dense, no direct stress at bone’s center Pg 123 Shapes of Bones Flat = skull, sternum, clavicle Irregular = pelvis, vertebrae Short = carpals, patella Long = femur, phalanges, metacarpals, humerus Anatomy of a Long Bone Diaphysis Medullary Cavity Nutrient Art & Vein 2 Epiphyses Epiphyseal Plates Epiphyseal Art & Vein Periosteum Outer: Dense irregular CT Inner: Osteoblasts, osteoclasts Does not cover epiphyses Attaches to bone matrix via collagen fibers Endosteum Osteoblasts, osteoclasts Covers trabeculae, lines medullary cavity training.seer.cancer.gov/.../illu_long_bone.jpg 2 Types of Bone Formation Endochondral Ossification: All other bones Begins with a cartilaginous model Perichondrium becomes replaced by periosteum Cartilage calcifies Medullary cavity is formed by action of osteoclasts Epiphyses grow and eventually calcify Epiphyseal plates remain cartilage for up to 20 years Intramembranous Ossification Membrane bones: most skull bones and clavicle Osteoblasts in membrane secrete osteoid that mineralizes Trabeculae form between blood vessels, thickens to become compact bone at periphery Osteocytes maintain new bone tissue Periosteum forms over it Bone Growth & Remodeling GROWTH Appositional Growth = widening of bone Bone tissue added on surface by osteoblasts of periosteum Medullary cavity maintained by osteoclasts Lengthening of Bone Epiphyseal plates enlarge by chondroblasts Matrix calcifies (chondrocytes die and disintegrate) Bone tissue replaces cartilage on diaphysis side REMODELING Due to mechanical stresses on bones, their tissue needs to be replaced Osteoclasts-take up bone ( = breakdown) release Ca2++ , PO4 to body fluids from bone Osteoblasts-form new bone by secreting osteoid Ideally osteoclasts and osteoblasts work at the same rate! Histology of Bone “Ground” Compact Bone Components of Bone Summarized Cells Matrix Osteoblasts Gel-like ground substance calcified with inorganic salts Osteocytes Collagen Fibers Osteoclasts 4) Blood: Atypical Connective Tissue Function: Transports waste, gases, nutrients, hormones through cardiovascular system Helps regulate body temperature Protects body by fighting infection Derived from mesenchyme Hematopoiesis: production of blood cells Occurs in red bone marrow In adults, axial skeleton, girdles, proximal epiphyses of humerus and femur Blood Cells Erythrocytes: (RBC) small, oxygen-transporting most abundant in blood no organelles, filled w/hemoglobin pick up O2 at lungs, transport to rest of body Platelets = Thrombocytes: fragments of cytoplasm plug small tears in vessel walls, initiates clotting Leukocytes: (WBC) complete cells , 5 types fight against infectious microorganisms stored in bone marrow for emergencies Components of Blood Summarized Cells Matrix Erythrocytes (red blood cells) Plasma (liquid matrix) Leukocytes (white blood cells) NO fibers Platelets 4 Types of Tissue 1)Epithelium 2)Connective 3)Muscle 4)Nervous Muscle Tissue Muscle cells/fibers Elongated Contain many myofilaments: Actin & Myosin FUNCTION Movement Maintenance of posture Joint Stabilization Heat Generation Three types: Skeletal, Cardiac, Smooth Skeletal Muscle Tissue (each skeletal muscle is an organ) Cells Long and cylindrical, in bundles Multinucleate Obvious Striations Skeletal Muscles-Voluntary Connective Tissue Components: Endomysium-surrounds fibers Perimysium-surrounds bundles Epimysium-surrounds the muscle Attached to bones, fascia, skin Origin & Insertion academic.kellogg.cc.mi.us/.../muscular.htm Cardiac Muscle Cells Branching, chains of cells Single or Binucleated Striations Connected by Intercalated discs Cardiac Muscle-Involuntary Myocardium-heart muscle Pumps blood through vessels Connective Tissue Component Endomysium: surrounding cells www.answers.com Smooth Muscle Tissue Cells Single cells, uninucleate No striations Smooth Muscle-Involuntary 2 layers-opposite orientation (peristalsis) Lines hollow organs, blood vessels Connective Tissue Component Endomysium: surrounds cells 4 Types of Tissue 1)Epithelium 2)Connective 3)Muscle 4)Nervous Nervous Tissue Neurons: specialized nerve cells conduct impulses Cell body, dendrite, axon Interneuron: between motor & sensory neuron in CNS Characterized by: No mitosis (cell replication) Longevity High metabolic rate www.morphonix.com Nervous Tissue: control Support cells (= Glial): nourishment, insulation, protection Satellite cells-surround cell bodies within ganglia Schwann cells-surround axons Microglia-phagocytes Oligodendrocytes-produce myelin sheaths around axons Ependymal cells-line brain/spinal cord, ciliated,help circulate CSF Brain, spinal cord, nerves Integumentary System Functions Protection Mechanical, thermal, chemical, UV Cushions & insulates deeper organs Prevention of water loss Thermoregulation Excretion Salts, urea, water Sensory reception Microanatomy - Layers of the Skin Epidermis Keratinocytes Dermis Hypodermis / subcutis Loose connective tissue Anchors skin to bone or muscle Skin Appendages = outgrowths of epidermis Hair follicles Sweat and Sebaceous glands Nails 15minbeauty.blogspot.com Cell Layers of the Epidermis Stratum Stratum Stratum Stratum Stratum corneum (superficial) lucidum granulosum spinosum basale (deep) 15minbeauty.blogspot.com Layers of the Dermis Highly innervated Highly vascularized Collagen & Elastic fibers 2 layers: Papillary layer (20%) Areolar CT Collagen Innervation Hair follicles Reticular layer (80%) DICT Glands 2.5 million sweat glands!! Smooth muscle fibers Innervation www.uptodate.com/.../Melanoma_anatomy.jpg Hypodermis Also called superficial fascia Areolar & Adipose Connective Tissue Functions Store fat Anchor skin to muscle, etc. Insulation Structure of Tubular Organs LUMEN Tunica Mucosa Lamina epithelialis Lamina propria Lamina muscularis mucosa Tunica Submucosa Tunica Muscularis Inner circular Outer longitudinal Pg 313 Tunica Adventitia / Serosa Adventitia – covers organ directly Serosa – suspends organ in the peritoneal cavity