Chapter 4-6 study guide

Cell Junctions

Contact points between adjacent plasma membranes of tissue cells.

Tight Junctions

Connect cells of tissues that line surfaces of organs; forms fluid-tight seals.

Adherens Junctions

Made of plaque and transmembrane glycoproteins (cadherins) that connect adjacent cells.

Desmosomes

Composed of plaque and cadherins linking cytoskeletons of adjacent cells; provides stability.

Hemidesmosomes

Anchor cells to the basement membrane using integrins; do not link adjacent cells.

Gap Junctions

Allow communication between cells by permitting ions and small molecules to pass.

Epithelial Tissue

Covers body surfaces, lines hollow organs and body cavities, and forms glands.

Simple Epithelium

Single layer of cells; may be squamous, cuboidal, or columnar.

Cuboidal Epithelium

Single layer of cube-shaped cells; functions in secretion and absorption.

Columnar Epithelium

Single layer of tall cells; can be ciliated or nonciliated.

Stratified Epithelium

Multiple layers of cells; can be squamous, cuboidal, or columnar.

Transitional Epithelium

Permits stretching, found in urinary bladder and ureters.

Endocrine Glands

Ductless glands that secrete hormones into the bloodstream.

Exocrine Glands

Glands that secrete substances into ducts.

Merocrine

Mode of secretion via exocytosis; most common method.

Apocrine

Mode of secretion where cells pinch off at the apical surface.

Holocrine

Mode of secretion where cells accumulate substances until rupture.

Connective Tissue

Supports, protects, binds organs, stores energy, and provides immunity.

Loose Connective Tissue

Includes areolar, adipose, and reticular tissues that support and bind other tissues.

Dense Connective Tissue

Includes regular, irregular, and elastic tissues that provide strength and elasticity.

Muscle Tissue

Tissue responsible for movement; includes skeletal, cardiac, and smooth muscle.

Nervous Tissue

Tissue that detects and responds to stimuli; includes neurons and neuroglia.

Epidermis

Outer layer of skin composed of stratified squamous epithelium.

Dermis

Connective tissue layer beneath the epidermis containing blood vessels and glands.

Hypodermis (Subcutaneous Layer)

Layer of fat that provides insulation and stores energy.

Sebaceous Glands

Oil glands that lubricate skin and hair.

Sudoriferous Glands

Sweat glands that regulate body temperature.

Osteoblasts

Bone-building cells.

Osteocytes

Mature bone cells that maintain bone tissue.

Osteoclasts

Bone cells that break down bone tissue.

Intramembranous Ossification

Bone formation that occurs from fibrous membranes.

Endochondral Ossification

Bone formation that occurs from cartilage.

Calcium Homeostasis

Regulates blood calcium levels through hormones like PTH and calcitonin.

Mesenchyme

Found under the skin in embryos, forms almost all other types of connective tissue

Mucoid (mucous) connective tissue

Found in the umbilical cord in a fetus, offers support.

Areolar Tissue

Loose connective tissue located in the hypodermis that provides support and elasticity, containing collagen and elastin fibers.

Adipose tissue

Loose connective tissue that stores fat, located in the hypodermis and around the heart.

Reticular Tissue

Loose connective tissue that provides framework for organs, located in spleen and lymph nodes

Dense Regular Tissue

Connective tissue that attaches to muscles and bones and forms tendons and ligaments, providing strength and stability.

Dense Irregular Tissue

Connective tissue that is arranged irregularly, located in dermis of the skin.

Elastic tissue

Connective tissue that allows stretching, found in arteries and lungs.

Hyaline Cartilage

Most common cartilage type, providing support. Found at ends of long bones and in the nose.

Fibrous Cartilage

Cartilage that supports and joins structures, found between vertebral discs

Elastic Cartilage

Cartilage that provides elasticity, found in the external ear.

Blood

Connective tissue that transports oxygen and carbon dioxide, located in blood vessels.