Human Anatomy & Physiology Mrs. Hodges Room A204 Per 1, 2, 3

Anatomical Directions Anatomical position Illustrated at the left Anatomical Directions-(for the biped) Anterior (ventral) vs. Posterior (dorsal) Medial vs. Lateral Superior (cranial) vs. Inferior (caudal) Superficial vs. Deep Proximal vs. Distal Anatomical Planes Frontal = Coronal Transverse = Cross Section Sagittal

Cell Connections Cells are connected to neighboring cells via: Proteins – adjacent proteins in membranes fuse to form: Cell Junctions Tight Junctions - plasma membrane of adjacent cells fuse; impermeable Desmosomes-adhesive spots on lateral sides Gap junction-spot-like junction occurring anywhere, lets small molecules pass

Histology Study of tissues A tissue is a group of cells with similar structure and embryonic origin working together to perform a particular function in the body.

Tissues: groups of cells closely associated that have a similar structure and perform a related function Four types of tissue A. Epithelial = covering/lining B. Connective = support C. Muscle = movement D. Nervous = control Most organs contain all 4 types

A. EPITHELIAL TISSUE: sheets of cells that cover a surface or line a cavity Functions Protection Secretion Absorption

How are epithelial tissues classified? Shape Squamous Cuboidal Columnar Number of Layers Simple: single layer Stratified: many layers

8 Specific Epithelial Tissues Simple Simple squamous Simple cuboidal Simple columnar Pseudostratified

8 Specific Epithelial Tissues Simple Simple squamous Simple cuboidal Simple columnar Pseudostratified Stratified Stratified squamous Stratified cuboidal Stratified columnar transitional

Can You Identify the Classes of Epithelium? Quiz!! E Can You Identify the Classes of Epithelium? D A B C

Structural Characteristics of Epithelium Cellularity Mostly composed of cell Specialized Contacts Composed mostly of sheets Polarity Has one free surface, the other is attached to an underlying tissue Avascular No blood vessels Regenerative Replaces cells with like cells Basement Membrane Is the foundation

B. CONNECTIVE TISSUE Structural Characteristics Cells Fibro- -blast = immature cell that secretes matrix Hemocyto- Chondro- -cyte = mature cell that maintains matrix Osteo- Extracellular matrix Tissue component that is NOT the cells and is made up of: ground substance = amorphous substance that fills space between cells and consists of interstitial fluid, proteins and polysaccharides. The more polysaccharides the stiffer the ground substance. fibers = interspersed throughout the ground substance and provides strength to the matrix.

FIBER TYPES Reticular – Collagen (aka white) – Elastic (aka yellow) – Tough stronger than steel fibers of same size provide high tensile strength (resists longitudinal stress). Elastic (aka yellow) – Can be stretched to 1.5X its length recoil to original size found where great elasticity is needed Reticular – Fine collagenous fibers that form a delicate branching network within solid organs such as spleen and liver.

4 Types of Connective Tissue 1. Connective Tissue Proper Made by fibroblasts 2. Cartilage Made by chondroblasts 3. Bone Tissue Made by osteoblasts 4. Blood Made by hemocytoblasts

1) Connective Tissue Proper LOOSE Areolar Adipose Reticular DENSE Regular Irregular Elastic

2) Cartilage Chondroblasts produce cartilage tissue More abundant in embryo than adult Firm, Flexible Resists compression (eg) trachea, meniscus 80% water Avascular, NOT Innervated (that means no blood, no pain)

Cartilage in the Body Three types: Hyaline Elastic Fibrocartilage most abundant support via flexibility/resilience found at limb joints, ribs, nose very fine collagen fibers Elastic many elastic fibers in matrix great flexibility Found external ear, epiglottis Fibrocartilage resists both compression and tension found in menisci, intervertebral discs

3) Bone Tissue Compact Spongy (Cancellous) cells contained in spaces called lacuna fine collagen fibers ground substance contains minerals Spongy (Cancellous) Looks like a sponge Spaces are filled with red bone marrow which is hematopoietic tissue

4) Blood Formed by hemocytoblasts in red bone marrow which is hematopoietic tissue Functions: Transports waste, gases, nutrients, hormones through cardiovascular system Helps regulate body temperature Protects body by fighting infection Cells erythrocytes leukocytes thrombocytes Matrix = Plasma

C. MUSCLE TISSUE Consists of cells that are specialized for generating a contraction. Cells are elongated and can become shorter and thicker. Three Types: Skeletal, Cardiac, Smooth

MUSCLE TISSUE FUNCTIONS Produce movement Generate heat Maintain posture Stabilize joints Characteristics common to ALL muscle tissue: made of many cells close together well vascularized tissue elongated cells contain myofilaments ( contractile proteins actin and myosin)

Skeletal Muscle Tissue (each gross skeletal muscle is an organ) Cells Long and cylindrical, in bundles Multinucleate Obvious Striations Voluntary Attached to bones, fascia, skin pg 235

Cardiac Muscle Cells Cardiac Muscle-Involuntary Found only in the heart Branching cells uninucleated Striations Connected by Intercalated discs Cardiac Muscle-Involuntary Be Mine

Smooth Muscle Tissue Cells Single cells, uninucleate No striations Involuntary 2 layers-opposite orientation (circular and longitudinal arrangement) Found in hollow, muscular organs including blood vessels

D. Nervous Tissue Neurons: specialized nerve cells Cell body, dendrite, axon Brain, spinal cord, nerves

“May I please be excused? My brain is full!!”