Chapter 5: The Human Tissues - Anatomy & Physiology Flashcards

Flashcards covering tissue categories, histology techniques, embryonic origin, epithelial, connective, nervous, and muscular tissues, cellular junctions, glands, membranes, and tissue repair based on Saladin's Anatomy & Physiology.

What are the four primary categories of adult tissues in the human body?

Epithelial tissue, Connective tissue, Nervous tissue, and Muscular tissue.

What is the anatomical definition of an organ?

A structure with discrete boundaries that is composed of two or more tissue types.

What are the three primary embryonic germ layers and the mature tissues derived from each?

Ectoderm (gives rise to epidermis and nervous system), Endoderm (gives rise to mucous membrane lining digestive and respiratory tracts, and digestive glands), and Mesoderm (becomes mesenchyme, giving rise to cartilage, bone, and blood).

What are the three standard planes of section used to prepare tissue specimens for histology?

Longitudinal section (l.s.), cross section (c.s. or t.s.), and oblique section.

What is the basement membrane, and what is its function?

A layer composed of collagen, glycoproteins, and protein-carbohydrate complexes located between an epithelium and underlying connective tissue that anchors the epithelium to the tissue below.

What type of epithelial tissue is shown in the micrograph, and what are its primary functions?

Simple squamous epithelium; it permits rapid diffusion or transport of substances and secretes serous fluid.

Identify the epithelial tissue pictured and list two of its representative anatomical locations.

Simple cuboidal epithelium; found in kidney tubules, liver, thyroid, mammary glands, salivary glands, and bronchioles.

Identify the simple epithelial tissue shown and describe its characteristic microscopic features.

Simple columnar epithelium; consists of a single row of tall, narrow cells with oval nuclei in the basal half, a brush border of microvilli, and mucus-secreting goblet cells.

What epithelial tissue type is displayed in this slide, and what structural feature propels mucus across its apical surface?

Ciliated pseudostratified columnar epithelium; cilia on its apical surface propel mucus.

What distinguishes keratinized stratified squamous epithelium from nonkeratinized stratified squamous epithelium?

Keratinized stratified squamous epithelium contains a surface layer of dead, scaly cells resistant to abrasion and water loss (found on skin surface), whereas nonkeratinized stratified squamous lacks this dead layer and lines moist internal cavities (such as esophagus and vagina).

Identify the tissue shown in the diagram and state where it is typically located.

Urothelium (transitional epithelium); found lining the ureter and urinary bladder.

What are the primary cell types found in fibrous connective tissue and their functions?

Fibroblasts (produce fibers and ground substance), Macrophages (phagocytize foreign material), Leukocytes (white blood cells for immune defense), Plasma cells (synthesize antibodies), Mast cells (secrete heparin and histamine), and Adipocytes (fat cells).

What are the three types of protein fibers present in connective tissue matrix?

Collagenous fibers (tough, flexible, stretch-resistant collagen), Reticular fibers (thin, glycoprotein-coated collagen forming structural frameworks), and Elastic fibers (elastin protein enabling stretch and recoil).

Identify the loose connective tissue shown in this slide and name its primary locations.

Areolar tissue; found underlying epithelia, in serous membranes, between muscles, and surrounding nerves and blood vessels.

Identify the connective tissue shown in the micrograph and state its structural role in lymphatic organs.

Reticular tissue; forms a supportive stroma (framework) for lymphatic organs such as the spleen, lymph nodes, thymus, and bone marrow.

What type of dense connective tissue is depicted in the image, and what is its primary structural organization?

Dense regular connective tissue; characterized by densely packed, parallel collagen fibers with compressed fibroblast nuclei.

Identify the connective tissue type shown and state its function.

Dense irregular connective tissue; withstands unpredictable physical stresses in the deep layer of skin and organ capsules.

How do white adipose tissue (WAT) and brown adipose tissue (BAT) differ in function and distribution?

White adipose tissue is the predominant adult fat providing energy storage, thermal insulation, and cushioning; brown adipose tissue is found mainly in fetuses and infants and functions as a heat-generating tissue due to its high density of blood vessels and mitochondria.

What type of cartilage is pictured in this slide, and where is it found in the human body?

Hyaline cartilage; found in articular cartilage, costal cartilage, trachea, larynx, and fetal skeleton.

Describe the structural organization of compact bone as shown in this histology image.

Organized into cylindrical osteons consisting of concentric lamellae surrounding a central (osteonic) canal that contains blood vessels and nerves, with osteocytes residing in lacunae connected by canaliculi.

What are the main formed elements and fluid component of blood?

Blood plasma (liquid ground substance) and formed elements, which include erythrocytes (RBCs), leukocytes (WBCs), and platelets.

What structural parts comprise a neuron as shown in this histology slide?

Cell body (houses nucleus and organelles), dendrites (receive incoming signals), and axon (sends outgoing signals).

Compare the structural characteristics and voluntary control of skeletal, cardiac, and smooth muscle tissues.

Skeletal muscle: long, cylindrical, striated, multinucleated, voluntary; Cardiac muscle: short, branched, striated, single central nucleus, intercalated discs, involuntary; Smooth muscle: short, fusiform, non-striated, single central nucleus, involuntary.

Describe the distinct functions of tight junctions, desmosomes, hemidesmosomes, and gap junctions.

Tight junctions seal intercellular spaces near apical surfaces; desmosomes hold cells together to resist mechanical stress; hemidesmosomes anchor basal epithelial cells to the basement membrane; gap junctions form ringlike connexon channels allowing ions and solutes to pass directly between cells.

What are the three modes of exocrine secretion and how do they release their products?

Eccrine (merocrine) releases products by exocytosis; Apocrine involves lipid droplets budding from the cell surface covered by cytoplasm and plasma membrane; Holocrine involves full cell accumulation of product followed by cell disintegration.

What three sublayers make up a mucous membrane (mucosa)?

Epithelium, lamina propria (areolar tissue), and muscularis mucosae (smooth muscle).

Define hyperplasia, hypertrophy, and neoplasia.

Hyperplasia is tissue growth through cell multiplication; Hypertrophy is tissue enlargement via increased cell size; Neoplasia is the development of a tumor composed of abnormal, nonfunctional tissue.

What is the distinction between tissue regeneration and fibrosis during wound repair?

Regeneration replaces damaged cells with the same cell type, fully restoring normal function; Fibrosis replaces damaged tissue with scar tissue (collagen), holding the structure together without restoring function.

What are the four sequential stages of skin wound healing?

$1$) Bleeding into the wound and histamine release; $2$) Blood clot and scab formation with macrophage activity; $3$) Formation of granulation tissue through capillary infiltration and fibroblastic collagen deposition; $4$) Epithelial regeneration and connective tissue fibrosis (remodeling phase).

What medical condition is pictured in this image, and what is its primary cause?

Dry gangrene of the foot; caused by tissue necrosis due to insufficient blood supply, commonly occurring as a complication of diabetes mellitus.