Introduction and Tissues

Human AnatomyBIOL 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 181

Hierarchy of Structural OrganizationOrgan 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 341Urinary System

Hierarchy of Structural Organization

Organism

� An individual human, animal, plant, etc……

� Made up all of the organ systems

� Work together to sustain life

Anatomical DirectionsAnatomical 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 5

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

Reference Point

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

� 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

Highly regenerative

Classification of Epithelium-based

on number of layers and cell shape

Layers

� Simple

� Stratified

� Stratified layers characterized by shape of apical layer

� Psuedostratified

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)� Thins when stretches� Hollow urinary organs

All histology pictures property of BIOL 1010 Lab

Special Epithelium

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

Features of Lateral Surface of Epithelium

Cells are connected to neighboring cells via:� Contour of cells-wavy contour fits together

� Cell Junctions (3 common)� Desmosomes

� Proteins hold cells together to maintain integrity of tissue

� Tight Junctions� Plasma membrane of adjacent cells fuse, nothing passes

� Gap junction� Proteins allow small molecules to pass through

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:

� Unicellular vs. multicellular

� Exocrine vs. Endocrine

Page 138

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

� Unicellular or Multicellular

� (ex) goblet cells, 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) Connective Tissue Proper

2) Cartilage

3) Bone Tissue

4) Blood

Connective Tissue (CT): most abundant and diverse tissue

Four ClassesFunctions include connecting, storing &

carrying nutrients, protection, fight infectionCT contains large amounts of non-living

extracellular matrixContains a variety of cells and fibers Some types vascularized All CT originates from mesenchyme� Embryonic connective 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

Components of Connective Tissue

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

1) Connective Tissue Proper

Two kinds: Loose CT & Dense CT

� Functions

� Support and bind to other tissue

� Hold body fluids

� Defends against infection

� Stores nutrients as fat

� Each function performed by different kind of fibers and cells in specific tissue

Defense from Infection

Areolar tissue below epithelium is body’s first defenseCells 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

Loose CT Proper

Areolar CT

� All types of fibers present

� All typical cell types present

� Surrounds blood vessels and nerves

Specialized Loose CT Proper

Adipose tissue

� Loaded with adipocytes, highly vascularized, high metabolic activity

� Insulates, produces energy, supports

� Found in hypodermis under skin

Reticular CT

� Contains only reticular fibers

� Forms caverns to hold free cells, forms internal “skeleton” of some organs

� Found in bone marrow, holds blood cells, 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

Dense regular Dense irregular

Components of CT Proper Summarized

Cells Matrix

Fibroblasts Gel-like ground substance

Defense cells-macrophages

-white blood cells

Collagen fibers

Reticular fibers

Elastic fibers

Adipocytes

2) CartilageChondroblasts 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

� fibers 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

(in growing cartilage)

Lots of water

Fibroblasts Some have collagen and elastic fibers

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 TissueOsteoblasts� Secrete organic part of bone matrix

Osteocytes� Mature bone cells� Sit in lacunae� Maintain bone matrix

Osteoclasts� Degrade and reabsorb bone

Periosteum� External layer of CT that surrounds bone

� Outer: Dense irregular CT� Inner: Osteoblasts, osteoclasts

Endosteum� Internal layer of CT that lines cavities and covers trabeculae� Contains osteoblasts and osteoclasts

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 through center of osteon

� Contains blood vessels and nerves

� Connected to each other by perforating (Volkman) canals

Interstitial lamellae fills spaces and forms periphery

www.mc.vanderbilt.edu/.../CartilageandBone03.htm

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

Bone Anatomy: Spongy bone

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 Artery & Vein

2 Epiphyses� Epiphyseal Plates� Epiphyseal Artery & Vein

Periosteum� Does not cover epiphyses

Endosteum� Covers trabeculae of spongy bone� Lines medullary cavity of long bones

training.seer.cancer.gov/.../illu_long_bone.jpg

2 Types of Bone Formation

Intramembranous Ossification

� Membrane bones: most skull bones and clavicle

� Osteoblasts in membrane secrete osteoid that mineralizes

Endochondral Ossification: All other bones � Begins with a cartilaginous model

� Cartilage calcifies

� Medullary cavity is formed by action of osteoclasts

� Epiphyses grow and eventually calcify� Epiphyseal plates remain cartilage for up to 20 years

Bone Growth & RemodelingGROWTH� 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 & osteoblasts work at the same rate!

Components of Bone Tissue Summarized

Cells Matrix

Osteblasts Gel-like ground substance calcified with inorganic salts

Fibroblasts Collagen fibers

Osteocytes

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

Leukocytes: (WBC) complete cells , 5 types

fight against infectious microorganisms

stored in bone marrow for emergencies

*Platelets = Thrombocytes:

fragments of cytoplasm

plug small tears in vessel walls, initiates clotting

Components of Blood Summarized

Cells Matrix

Erythrocytes

(red blood cells)

Plasma

(liquid matrix)

Leukocytes

(white blood cells)

NO fibers

*Platelets

(cell fragments)

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

CellsSingle cells, uninucleate

No striations

Smooth Muscle-Involuntary2 layers-opposite orientation (peristalsis)

Found in hollow organs, blood vessels

Connective Tissue ComponentEndomysium: 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

Characterized by:� No mitosis (cell replication)

� Longevity

� High metabolic rate

www.morphonix.com

Nervous Tissue: control

Support cells (= Neuroglial): nourishment, insulation, protection� Satellite cells-surround cell bodies within ganglia

� Schwann cells-surround axons (PNS)

� 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� Epithelium

Dermis� Connective tissue

Hypodermis / subcutis� Loose connective tissue

� Anchors skin to bone or muscle

Skin Appendages = outgrowths of epidermis� Hair follicles

� Sweat and Sebaceous glands

� Nails

www.uptodate.com/.../Melanoma_anatomy.jpg

Cell Layers of the Epidermis

Stratum corneum

� Dead keratinocytes

Stratum lucidum

� Only in “thick” skin

� Dead keratinocytes

Stratum granulosum

� Water proofing

Stratum spinosum

� Resists tears and tension

Stratum basale

� Sensory receptors

� Melanocytes

� Keratinocytes (in all layers)15minbeauty.blogspot.com

Layers of the DermisHighly innervated

Highly vascularized

Collagen & Elastic fibers

2 layers:� Papillary layer (20%)

� Areolar CT

� Collagen & Elastic fibers

� Innervation

� Hair follicles

� Reticular layer (80%)� Dense irregular CT

� Glands� sebum

� 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

Tunica Adventitia / Serosa� Adventitia – covers organ directly

� Serosa – suspends organ in the peritoneal cavity