1.2 Lecture: Tissue Types, Organ Systems, & Basics of Integumentary, Musculoskeletal, & Vascular Systems

Flashcards with vocabulary terms and definitions.

Parallel Muscle Fiber Architecture

Fibers run along the muscle’s long axis; produce fast contractions with less force.

Fusiform Muscle Fiber Architecture

Spindle-shaped; taper at both ends; moderate power output.

Pennate Muscle Fiber Architecture

Oblique fibers insert into a central tendon. Greater cross-sectional area = higher force. High power potential but reduced range of motion.

Convergent Muscle Fiber Architecture

Broad origin, narrow insertion.

Circular Muscle Fiber Architecture

Surround openings/orifices; regulate passage.

Origin (muscle)

Often the stationary attachment, often proximal or medial.

Insertion (muscle)

Often the mobile attachment, often distal or lateral.

Reflexive contractions

Involuntary contractions of skeletal muscle.

Tonic contractions

Continuous, low-level contractions that do not produce movement. Function to maintain postural tone and joint stability. Provides readiness for voluntary movement.

Isometric contractions

A muscle produces force without changing length. There is no visible movement, but tension increases above tonic levels.

Istonic contractions

Involve change in muscle length with movement.

Concentric contractions

Muscle shortens while generating force.

Eccentric contractions

Muscle lengthens while under tension.

Motor Unit

A single motor neuron and all of the skeletal muscle fibers it innervates.

Agonist (Prime Mover)

Primary muscle generating a specific movement in a region.

Antagonist

Opposes the prime mover; controls movement.

Synergist

Assists the agonist; stabilizes motion.

Fixator

Stabilizes proximal origin or joint.

Chemical Level (Structural Hierarchy)

Atoms form molecules such as proteins, lipids, and nucleic acids.

Cellular Level (Structural Hierarchy)

Molecules combine to form cells, each with specialized functions.

Tissue Level (Structural Hierarchy)

Groups of similar cells perform common functions.

Organ Level (Structural Hierarchy)

Organs consist of two or more tissue types performing specific tasks.

Organ System Level (Structural Hierarchy)

Systems include functionally related organs.

Organismal Level (Structural Hierarchy)

All systems work together to sustain the life of a human being.

Epithelial Tissue

Highly cellular with minimal extracellular matrix (ECM). Avascular but innervated. Anchored to a basement membrane. Capable of rapid regeneration

Connective Tissue

Most abundant tissue type. Derived from mesenchyme. Widely variable vascularity.

Connective Tissue Characteristics

Derived from mesenchyme. Widely variable vascularity (e.g., cartilage is avascular)

Muscle Tissue

Specialized for contraction. Contains actin and myosin filaments. Highly vascularized. Cells are elongated and referred to as muscle fibers

Skeletal Muscle

Voluntary, striated.

Cardiac Muscle

Involuntary, striated

Smooth Muscle

Involuntary, non-striated

Nervous Tissue Functions

Initiates and transmits electrical impulses. Coordinates rapid responses to internal/external stimuli

Integumentary System Functions

Barrier protection chemical protection, thermoregulation, immune surveillance, sensory reception, vitamin D synthesis, and secretion

Skeletal System Functions

Structural support, organ protection, calcium storage, hematopoiesis

Muscular System Functions

Movement, posture, thermogenesis

Nervous System Functions

Control center for sensation, integration, and motor function

Endocrine System Functions

Hormonal regulation of growth, metabolism, and reproduction

Cardiovascular System Functions

Transport of blood, gases, nutrients, hormones

Lymphatic/Immune System Functions

Fluid homeostasis, immune defense, lipid transport.

Respiratory System Functions

Ventilation, gas exchange, acid-base regulation

Digestive System Functions

Ingestion, digestion, absorption, excretion

Urinary System Functions

Filtration, waste excretion, fluid/electrolyte balance

Male Reproductive System Functions

Sperm production, testosterone secretion, fertilization

Female Reproductive System Functions

Oogenesis, menstruation, fetal development

Integumentary System

Skin + Hair + Sweat & Sebaceous glands

Epidermis

Avascular epithelial tissue (stratified squamous epethelium)

Dermis

Vascular connective tissue. Comprised mainly of collagen, elastic, and reticular fibers

Subcutaneous Layer/Hypodermis

Loose connective tissue and adipocytes

Epidermal Ridges

Downward projections of the epidermis

Dermal Papillae

Upward projections of the papillary layer of the dermis

Deep Fascia

Dense, organized connective tissue; contains no adipose

Stretch Marks (Striae Distensae)

Result from overstretching of collagen fibers during rapid growth or pregnancy

Tension Lines (Langer’s Lines)

Represent natural orientation of collagen bundles in the dermis

Superficial burn

Involves only epidermis

Partial-thickness burn

Involves epidermis and superficial dermis

Full-thickness burn

Involves epidermis and entire dermis

Fourth-degree burn

Extends to underlying fascia, muscle, or bone

Basal Cell Carcinoma

Origin in stratum basale. Most common, least dangerous. Rarely metastasizes

Squamous Cell Carcinoma

Origin in stratum spinosum. May metastasize if untreated

Malignant Melanoma

Origin in melanocytes. Most deadly skin cancer. Rapid metastasis; requires early detection

Long bones

femur, humerus; primary for leverage and movement

Short bones

carpals, tarsals; cube-shaped, absorb compressive forces

Flat bones

sternum, skull bones; protective and provide surface area for muscle attachment

Irregular bones

vertebrae, sphenoid; complex shapes with varied functions

Sesamoid bones

patella; embedded in tendons, reduce friction, alter muscle leverage

Diaphysis

compact bone shaft; contains medullary cavity with yellow marrow

Epiphyses

spongy (cancellous) bone at ends; red marrow housed in trabeculae

Metaphysis

transitional zone between shaft and epiphysis; location of growth plate (physis)

Epiphyseal (Growth) Plate

hyaline cartilage plate in children; responsible for longitudinal growth

Periosteum

dense irregular CT sheath with outer fibrous and inner osteogenic layers; anchors tendons

Endosteum

thin vascular membrane lining internal bone surfaces; osteogenic and remodeling activity

Red Marrow

hematopoietic; found in flat bones and epiphyses of long bones

Yellow Marrow

fat-rich; primarily in adult diaphyses

Intramembranous Ossification

Direct formation from mesenchymal tissue → osteoblasts. Occurs in flat bones of skull, mandible, clavicle

Endochondral Ossification

Hyaline cartilage model replaced by bone. Occurs in most long bones, vertebrae, and base of skull

Heart Function

Right atrium receives deoxygenated blood from systemic circulation, right ventricle pumps it to the lungs via pulmonary arteries for oxygenation, left atrium receives oxygenated blood from pulmonary veins, left ventricle pumps oxygenated blood to the systemic circulation via the aorta.

Veins

Return blood to the heart. Larger lumen, thinner walls, and valves to prevent backflow.

Veins

Return blood to the heart. Larger lumen, thinner walls, and valves to prevent backflow.

Capillaries

Microscopic vessels; connect arterioles and venules. Single layer of endothelium + basement membrane. Site of exchange: gases, nutrients, and waste products with tissues

Vena Comitans

Paired veins accompanying arteries, especially in extremities

Circumflex Arteries

Curve around structures

Perforating Vessels

Penetrate tissue to reach deeper targets

Anastomosis

Direct connection between two vessels without intervening capillaries

Recurrent Anastomosis

Vessel returns to supply a joint or structure

Collateral Circulation

Alternate route to ensure perfusion if primary path is blocked