ASCI 1101 - Animal Physiology Exam 1

What is anatomy?

The study of body structure: what parts are present, where they are located, and how they are arranged.

What is physiology?

The study of body function: what processes occur, how they are regulated, and how systems respond.

What do rumen papillae do?

They increase surface area for absorption of volatile fatty acids.

What is the function of the mammary gland?

It is secretory tissue that produces and releases milk.

Why are lung alveoli suited for gas exchange?

Their thin walls and rich capillary supply support exchange of oxygen and carbon dioxide.

What is the organization from simplest to most complex in the body?

Cell → tissue → organ → organ system → organism.

What are the four major tissue types?

Epithelial, connective, muscle, and nervous tissue.

What does epithelial tissue do?

It covers exposed surfaces, lines internal passageways and cavities, and forms glands.

What are the three epithelial cell shapes?

Squamous (thin and flat), cuboidal (square), and columnar (tall and rectangular).

What is simple epithelium?

Epithelium consisting of a single cell layer.

What is stratified epithelium?

Epithelium consisting of several cell layers, usually for protection.

Where is simple squamous epithelium found, and what is its role?

In areas of absorption or diffusion, including alveoli, mesothelium, and endothelium.

What is mesothelium?

Simple squamous epithelium lining the pleura, peritoneum, and pericardium.

What is endothelium?

Simple squamous epithelium lining heart chambers, blood vessels, and lymphatic vessels.

How do keratinized and nonkeratinized stratified squamous epithelia differ?

Keratinized epithelium resists water loss and dehydration; nonkeratinized epithelium resists abrasion but must remain moist.

Where is nonkeratinized stratified squamous epithelium found?

In the mouth, esophagus, vagina, and anus.

What is the main role of simple cuboidal epithelium?

Intense secretion and absorption with limited protection.

Where is simple cuboidal epithelium found?

Kidney tubules and smaller bronchioles.

Where is stratified cuboidal epithelium found?

Sweat ducts and mammary ducts.

What is transitional epithelium specialized for?

Repeated stretching and recoiling without damage, as in the urinary bladder.

What is the role of simple columnar epithelium?

Absorption and secretion while protecting against chemical stress.

Where is simple columnar epithelium found?

The small intestine, stomach, and large intestine.

What distinguishes pseudostratified epithelium?

All cells contact the basement membrane, and cilia help move material.

Where is pseudostratified epithelium found?

The nasal cavity, upper pharynx, larynx, trachea, bronchi, and oviduct.

What are the major components of connective tissue?

Specialized cells, extracellular protein fibers (collagen and elastic fibers), and fluid ground substance.

What are the main functions of connective tissue?

Framework, transport, organ protection, support, energy storage, and defense against pathogens.

What are the classes of connective tissue?

Connective tissue proper (loose and dense), fluid connective tissue, and supporting connective tissue.

What are examples of loose connective tissue?

Areolar, adipose, and reticular tissue.

What are examples of dense connective tissue?

Tendons and ligaments.

What are examples of fluid connective tissue?

Blood and lymph.

What are examples of supporting connective tissue?

Bone and cartilage.

What are the characteristics of cardiac muscle?

It is striated, involuntary, branched, found in heart walls, pumps blood, and regenerates minimally after injury.

What are the characteristics of smooth muscle?

It is nonstriated, involuntary, found in hollow organs, moves contents through the body, and regenerates relatively easily.

What are the characteristics of skeletal muscle?

It is striated, voluntary, attached to bone or fascia, and has long cylindrical fibers.

What is the function of nervous tissue?

Neurons receive, process, and send signals; neuroglia support, protect, and insulate.

What is histology?

The microscopic examination of tissues to identify normal structures and abnormalities such as disease or tumors.

What is fixation in histology?

Preservation of tissue, commonly using formaldehyde or ethanol.

What happens during embedding in histology?

Tissue is dehydrated with alcohol and embedded in paraffin.

What happens during sectioning in histology?

Thin tissue slices, about 5-15 microns, are cut and placed on glass slides.

What does hematoxylin stain?

Acidic structures blue.

What does eosin stain?

Basic structures pink.

What are the main functions of the skeletal system?

Support, protection, movement, mineral storage, hematopoiesis, and fat storage.

What structures make up the axial skeleton?

The skull, vertebral column, ribs, and sternum.

What structures make up the appendicular skeleton?

The limbs, girdles, and extremity bones.

What is bone tissue?

A connective tissue with bone cells and a mineralized extracellular matrix.

What are osteoprogenitor cells?

Mesenchymal stem cell-derived precursors of osteoblasts found on internal and external bone surfaces.

What do osteoblasts do?

They build bone by secreting collagen fibers and bone-matrix proteins and promoting mineral deposition.

What are osteocytes?

Mature osteoblasts trapped in lacunae that maintain bone matrix and communicate through canaliculi.

What do osteoclasts do?

They resorb bone, releasing hydrogen ions and enzymes that free calcium into the blood.

Where do osteoclasts originate?

From monocytes, not osteoprogenitor cells.

What is osteoid?

The organic portion of bone matrix, mainly collagen and other proteins, which resists stretching and twisting.

What is hydroxyapatite's role in bone?

It is the mineral component that gives bone resistance to compression.

What is compact bone?

Dense outer bone tissue organized into osteons.

What is an osteon?

A cylindrical structural unit of compact bone arranged parallel to the long axis of a bone.

What are lamellae?

Concentric sheets of mineralized osteoid surrounding central canals in an osteon.

What are Haversian canals?

Central canals in osteons containing blood and lymphatic vessels and nerve fibers.

What are Volkmann's canals?

Canals connecting Haversian canals and carrying vessels and nerves from bone surfaces toward the medullary cavity.

What is spongy bone?

Light, porous internal bone made of trabeculae; marrow fills the spaces between them.

What are trabeculae?

Fine columns forming the structural network of spongy bone.

What is an epiphysis?

An expanded end of a long bone with spongy bone inside and compact bone outside.

What is the diaphysis?

The tubular shaft of a long bone, composed mainly of compact bone around the medullary cavity.

What is the metaphysis?

The region joining the diaphysis and epiphysis; it contains the growth plate in growing bones.

What is the epiphyseal plate?

A hyaline-cartilage growth plate responsible for lengthwise bone growth; it becomes an epiphyseal line after ossification.

What is articular cartilage?

Hyaline cartilage covering joint surfaces that reduces friction and absorbs shock.

What is the periosteum?

A membrane covering external bone surfaces except in joint cavities; it supports growth and repair and carries vessels and nerves.

What is the endosteum?

A lining of internal bone surfaces and trabeculae that supports bone growth, repair, and remodeling.

What is the medullary cavity?

The central cavity in a bone shaft where marrow is stored.

What does red bone marrow do?

It produces platelets, red blood cells, and white blood cells.

What is yellow bone marrow?

Primarily adipose tissue that stores energy and can convert to red marrow when more blood-cell production is needed.

What is osteogenesis (ossification)?

Bone formation during embryonic development, growth, lifelong remodeling, and fracture repair.

How does mechanical loading affect bone?

Osteocytes sense strain; appropriate exercise strengthens bone, disuse weakens it, and overload can injure it.

What are the key minerals stored in bone matrix?

Calcium and phosphorus.

What is vitamin D's role in bone health?

It supports intestinal absorption of calcium and phosphorus.

What is calcitonin's effect on bone?

It can help reduce osteoclast activity.

Why does cartilage heal slowly?

It is avascular, so nutrients diffuse through its matrix rather than arriving via direct blood flow.

What do chondroblasts and chondrocytes do?

Chondroblasts build cartilage matrix; chondrocytes maintain it.

What are lacunae in cartilage?

Small spaces that house chondrocytes.

What is the perichondrium?

The outer connective tissue layer of cartilage; it is absent in articular cartilage and fibrocartilage.

Where is hyaline cartilage found and what does it do?

At articular surfaces, costal cartilage, tracheal rings, and growth plates; it supports low-friction movement, support, and endochondral growth.

Where is elastic cartilage found and what does it do?

In the external ear and epiglottis; it bends repeatedly and springs back.

Where is fibrocartilage found and what does it do?

In intervertebral discs, menisci, pubic symphysis, and tendon insertions; it resists compression and tensile forces.

What percentage of body mass is muscle tissue?

About 40-50%.

What are skeletal muscle's major functions?

Movement, posture, support of soft tissues, guarding entrances/exits, heat production, and protein storage.

What are myosatellite cells responsible for?

Regeneration of adult skeletal muscle.

What is the sarcolemma?

The cell membrane of a muscle fiber; changes in its transmembrane potential initiate contraction.

What is sarcoplasm?

The cytoplasm of a muscle fiber.

What are T tubules?

Deep sarcolemma invaginations that conduct electrical impulses into a muscle fiber so it contracts simultaneously.

What is the sarcoplasmic reticulum?

A membrane network around myofibrils that stores/releases calcium and helps transmit the action potential.

What are myofibrils?

Long parallel structures in muscle fibers composed of myofilaments organized into sarcomeres.

What are the thin and thick myofilaments?

Thin filaments are actin; thick filaments are myosin.

What is a sarcomere?

The repeating unit of thin and thick filaments in a myofibril; it produces the striated appearance of skeletal muscle.

What connective tissue layer surrounds an entire muscle?

Epimysium.

What connective tissue layer surrounds a fascicle?

Perimysium.

What connective tissue layer surrounds an individual muscle fiber?

Endomysium.

What structures do epimysium, perimysium, and endomysium form at muscle ends?

Tendons and aponeuroses that attach muscle to bone matrix.

What are the key steps of skeletal muscle contraction?

Neural stimulation, acetylcholine release at the neuromuscular junction, calcium release from the sarcoplasmic reticulum, then filament interaction and tension production.

What happens to bands during sliding-filament contraction?

The I and H bands shrink, while the A band remains the same length.

What is a motor unit?

A single neuron and all the muscle fibers it controls.

How is muscle tension increased?

By recruiting more motor units and increasing stimulation frequency.

What is tetanus in muscle physiology?

Maximum sustained contraction without a relaxation phase; it can be sustained only briefly.