Advanced A&P Test 1

Anatomic position

standing upright, feet parallel and on the floor, looking forward, arms at side with palms facing forward with thumbs away from body

Coronal Plane (frontal plane)

divides body into anterior (front) and posterior (back) parts

Transverse Plane (cross sectional plane, horizontal plane)

divided body into superior (upper) and inferior (lower) parts

Midsagittal plane (median plane)

divides body into equal left and right halves

Anterior

nearer the front

Posterior

further back in position; nearer the rear

Superior

Toward head

Inferior

Toward feet

Medial

Toward midline of body

Lateral

Away from the midline of the body

Proximal

Closer to trunk

Distal

Far from trunk

Axial Region

head, neck, and trunk; vertical axis of the body

Appendicular region

upper and lower limbs

Connective tissue

diverse, abundant, widely distributed. "glue" of the body

Cells

Various cells in different types of connective tissue. Ex: fibroblasts, osteocytes, and adipocytes

Protein Fibers

elastic fibers, collagen, reticular fibers

Ground substance

a mixture of proteins and carbohydrates with variable amounts of salts and water

Functions of connective tissue

physical protection, support and structural framework, binding of structures, storage, transport, immune protection

Connective Tissue Classification

Collagen fibers

long, strong, unbranched; most abundant protein in human body

Elastic Fibers

thinner than collagen, stretch easily, branch, and rejoin; allow structures to stretch and recoil

Reticular fibers

thinner than collagen fibers; form a branching, woven framework; found in the stroma of organs with abundant spaces such as liver etc..

Loose Connective tissue

serves as the body's packing material, found in spaces around organs

Dense connective tissue

strong, has fibers packed tightly together; Ex: tendons

Areolar connective tissue

contains all cells of connective tissue proper, especially fiborblasts; abundant ground substance, collagen, and elastic fibers; Ex: papillary layer of dermis

Adipose connective tissue

primarily composed of adipocytes, each containing a lipid droplet; stores energy, cushions organs, insulates. Ex: subcutaneous fat

Reticular connective tissue

meshwork of reticular fibers, fibroblasts, and leukocytes; provides supportive framework for many lymphatic organs. Ex: stroma of spleen

Dense irregular connective tissue

randomly arranged collagen fibers. Ex: reticular layer of dermis

Elastic connective tissue

many branching elastic fibers, allows stretching and recoil. Ex: walls of large, elastic arteries

Cartilage

firm, gel-like extracelluar matrix composed of protein and ground substances.

Chondrocytes

occupy small spaces enclosed by their extracellular matrix called lacunae

Hyaline cartilage

glassy matrix, most common type but also the weakest, smooth joint surfaces, model for bone growth; Ex: articular cartilage of long bones

Fibrocartilage

Parallel collagen fibers in matrix; absorbs shock; Ex: intervertebral discs

Elastic cartilage

numerous elastic fibers; extremely resilient and flexible; Ex: external ear

Bone connective tissue

2/3 of bones weight is inorganic; 1/3 is organic

Compact bone

calcifie matrix organized in osteons; protects organs, provided levers for movement, stores calcium; Ex: bones of the body

Fluid connective tissue

blood is fluid connective tissue consisting of plasma, erythrocytes(red blood cells), leukocytes(white blood cells), platelets

Skeletal muscle tissue

long, cylindrical, striated fibers. Voluntary muscle control

Cardiac muscle tissue

Branched (Y-shape) and shorter than skeletal fiber cells, striated, found in wall of the heart. Involuntary muscle control

Smooth muscle tissue

relatively short, wide in the middle, and tapered at the ends(fusiform). Found in walls of most internal organs. Involuntary muscle control.

Nervous tissue

consists of cells called neurons or nerve cells, and glial cells. Function: support, protect, and provide a framework.

Neurons

nerve cells capable of initiating and conducting electrical activity throughout the body

Glial

cells that support and protect neurons

Metaplasia

mature epithelium changes to a different form of mature epithelium

Hypertrophy

an increase in the size of existing cells

Atrophy

shrinkage of tissue by cell size or number

Necrosis

tissue death. Usually irreversible damage

Tissue Aging

epithelia thin, collagen production declines, repair processes lose efficiency, bones become brittle, muscle and nervous tissue begin to atrophy

Vitamin A

activates osteoblasts

Vitamin C

required for collagen synthesis

Vitamin D

stimulates calcium absorption from GI tract into bloods so that calcium is available for bone formation

Stress fracture

thin break due to increased activity, repetitive loads

Pathologic fracture

occurs in bone weakened by disease

Simple fracture

broken bone does not penetrate the skin

Compound fracture

broken bone penetrates the skin

Excitability

ability to respond to stimuli

Conductivity

ability to transmit electrical events along the cell membrane

Contractility

ability to generate tension and shorten cell length

Elasticity

ability to return to resting length after shortening or lengthening

Extensibility

ability to be stretched beyond resting length

Fascicle

bundle of muscle fibers

Muscle connective tissue covering

Epimysium

Fascicle connective tissue covering

Perimysium

Muscle Fiber connective tissue covering

Endomysium

Axons

pass through all 3 layers of connective tissue to form junctions with individual skeletal muscle fibers

EC: sliding filament theory

Motor unit

a single motor neuron and the muscle fibers it controls

Muscle Tone

resting tension in a skeletal muscle

Autorhythmic

able to generate electrical impulses without nerve stimulation

Slow oxidative fibers

small, aerobic, highly fatigue resistant. also called type I fibers

Fast oxidative fibers

intermediate size, fast contraction, aerobic and fatigue resistant. Also called type IIa

Fast glycolytic fibers

large, anaerobic, only contract for short burst. Also called type IIx.

Agonist

contraction produces the movement; also called the prime mover. EX tricep brachii is the agonist for forearm extension

Anatagonist

a muscle whose action opposes that of an agonist. EX biceps brachii is the antagonist for forearm extension

Synergist

a muscle that assists the agonist in performing its action. Coined the "helper" muscles such as the stabilizer muscles

Isometric contraction

length is constant; tension is changing

Isotonic contraction

tension is constant; length is changing

Concentric contraction

muscle is shortening

Eccentric contraction

muscle is lengthening