Human Anatomy (BIOL 1010)

1. Human Anatomy(BIOL 1010) E. Goffe eggoffe@ccri.edu Office 1132F (Providence)

2. 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

3. Hierarchy of the Body • Moleculesmade of chemicals (4 macromolecules in body) • carbohydrates, lipids, proteins, nucleic acids • Cellsmade of molecules • cells and organelles • Tissuemade of cells • epithelial, connective, muscular, nervous • Organsmade of tissues • made of >1 type of tissue • Systemsmade of organs • 11 systems in human body • Organismsmade of systems

4. 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

5. 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

6. 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

7. 4 Types of Tissue • Epithelium • Connective • Muscle • Nervous

8. 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

9. EPITHELIAL TISSUE: sheets of cells cover a surface or line a cavity(tissue type #1) • Functions • Protection • Secretion • Absorption • Ion Transport • Slippery Surface

10. Characteristics of Epithelium • Cellularity • Specialized Contacts • Polarity • Apical vs. Basal • Supported by Connective Tissue • Avascular • Innervated • Regenerative

11. 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

12. 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

13. 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 • 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

14. Features of the Basal Surface of Epithelium • Basement membrane = Sheet between the epithelial and connective tissue layers • Attaches epithelium to connective tissue below • 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

15. Glands: epithelial cells that make and secrete a water-based substance w/proteins • Exocrine Glands • Secrete substance onto body surface or into body cavity • Have ducts (simple vs. compound) • Unicellular (goblet cells) or Multicellular (tubular, alveolar, tubuloalveolar) • (ex) salivary, mammary, pancreas, liver

16. 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

17. 4 Types of Connective Tissue Connective Tissue Proper Cartilage Bone Tissue Blood

18. Connective Tissue (CT): most abundant and diverse tissue(tissue type #2) • 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

19. 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

20. 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

21. 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, jelly-like with sugar & protein molecules

22. 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

23. 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

24. 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

25. Components of CT Proper Summarized

26. 2) Cartilage • Chondroblastsproduce cartilage • Chondrocytes mature cartilage cells • More abundant in embryo than adult • Firm, Flexible • Resists compression • (eg) trachea, meniscus • 80% water • 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

27. 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

28. Components of Cartilage Summarized

29. 3) Bone Tissue:(a bone is an organ) • Functions: • 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

30. Components of Bone • Matrix • Mineralized with hydroxyappetite • Cells • Osteoblasts: secrete organic part of bone matrix • Osteocytes: mature bone cells, maintain bone matrix • Connective Tissue Proper • Periosteum: external layer of CT surrounds bone • Endosteum: internal layer of CT lines cavities and covers trabeculae • Both contain osteoblasts and osteoclasts • Bone is well-vascularized, highly innervated

31. Bone Anatomy: Compact bone • Compact bone: dense, external layer • Haversian system = osteon • long, cylindrical structures run parallel to long axis of bone • within each osteon, groups of concentric tubes (lamella) • Lamella: layer of bone matrix all fibers run in same direction • fibers on each lamella runs in opposite directions to one near it • Haversian canal-runs through center of osteon, contain blood vessels and nerves • Interstitial Lamella- pieces of bone matrix between osteon • Osteocytes between osteons

32. 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

33. Shapes of Bones • Flat = skull, sternum, clavicle • Irregular = pelvis, vertebrae • Short = carpals, patella • Long = femur, phalanges, metacarpals, humerus

34. 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

35. 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

36. 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!

37. Components of Bone Tissue Summarized

38. 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

39. 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

40. Components of Blood Summarized

41. Muscle Tissue (tissue type #3) • Muscle cells/fibers • Elongated • Contain many myofilaments: Actin & Myosin • FUNCTION • Movement • Maintenance of posture • Joint Stabilization • Heat Generation • Three types: Skeletal, Cardiac, Smooth

42. 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

43. 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

44. 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

45. 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

46. 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

47. Neuronal Anatomy • Synapse: cell junction where neurons communicate • One direction: presynaptic neuron, postsynaptic neuron • Presynaptic neuron • Synaptic vesicles fuses w/presynaptic membrane • Neurotransmitters released, • diffuse across synaptic cleft, bind to postsynaptic membrane • ٠Creates impulse (action potential) in that neuron ٠Cycle repeats

48. Integumentary System • Skin • Epidermis = epithelium • Dermis = connective tissue • Hypodermis = connective tissue • Skin Appendages = outgrowths of epidermis • Hair follicles • Sweat and Sebaceous glands • Nails

49. Integumentary System • Functions • Protection • Mechanical, thermal, chemical, UV • Cushions & insulates deeper organs • Prevention of water loss • Thermoregulation • Excretion • Salts, urea, water • Sensory reception

50. Layers of the Epidermis • Stratum corneum • Dead keratinocytes • Stratum lucidum • Dead keratinocytes • Stratum granulosum • Keratinocytes • Tonofilaments • Lamellated & keratohyaline granules • Stratum spinosum • Keratinocytes • Tonofilaments • Langerhans cells • Stratum basale • Keratinocytes • Melanocytes • Merkel receptors