Bone and Muscle Tissue Flashcards

Flashcards on Bone and Muscle Tissue

Bone

Hard, calcified connective tissue; can refer to osseous tissue or an organ

Osseous tissue

Two types are spongy bone and compact bone.

Spongy bone (trabecular/cancellous)

Strength with reduction in weight

Functions of Bone

Support, protection, attachment site for muscles, blood formation, electrolyte balance, pH balance, detoxification.

Diaphysis

Growing through

Epiphysis

Growing upon

Organic component of bone (1/3)

Collagen fibers and protein & carbohydrate complexes

Function of Collagen in Bone

Resistance to twisting and bending forces

Inorganic Component of Bone (2/3)

Calcium salts (mainly calcium phosphate salts)

Bone Cells

Osteoblasts (lay down bone tissue), Osteocytes (maintenance), Osteoclasts (remodeling)

Osteoblasts

Lay down bone tissue; non-mitotic

Osteoclasts

Multinucleate cells, bone macrophages

Osteon

Concentric rings of bone

Canaliculi

Small canals that house cell processes of osteocytes

Epiphyseal line

Represents mature, bony joint

Epiphyseal plate

Growing bone (lab class)

Rickets

Insufficient Vitamin D leads to defective mineralization of bones before epiphyseal closure

Characteristics of all Muscle types

Excitable, extensible, elastic, contractile, highly cellular, well vascularized

Main Functions of Muscle

Movement, stabilization, maintenance of posture, generating heat, blood glucose regulation

Skeletal Muscle

Voluntary & striated

Striated

Cross-striations across the muscle cells

Examples of Visceral Striated Muscle

Tongue, pharynx, upper part of the esophagus, lumbar part of the diagram

Refractory period

Time between when muscle is stimulated to contract and how long before it can be stimulated again

Myofibre

Muscle cell

Sarcolemma

Cell membrane

Sarcoplasm

Cytoplasm

Sarcoplasmic reticulum

SER (calcium storage)

Syncitium

Fusion of cells called myoblasts during embryonic development; functionally acting together as one cell

Satellite cells

Role in regeneration of damaged skeletal muscle

Myofibrils

Long protein cords inside the skeletal muscle cell

Myofilaments

A bundle of parallel protein microfilaments

Thick filaments

Myosin

Thin filaments

Actin

Sarcomeres

Contractile units of the muscle fiber

Sliding filament theory

Actin and myosin filaments slide over each other = shortening of the sarcomere

Motor unit

One nerve fibre + all the muscle fibres it innervates

Small motor units

1 motor neuron + 3-6 muscle fibres (cells)

Large motor units

1 motor neuron + up to 1000 muscle fibres (cells)

Cardiac Muscle

Involuntary & striated

Cardiac muscle

Cells are called cardiomyocytes (cardiocytes)

Intercalated discs

Mechanical junctions (tissue integrity) and Electrical junctions (allows each cardiocyte to directly stimulate adjoining cells)

Cardiac muscle

Syncytium (all cells acting as one)

Smooth Muscle

Involuntary & non-striated

Smooth muscle

Visceral muscle

Stimuli that smooth muscle responds to

Chemicals, hormones, pH, CO2, O2, temperature, stretch

Fusiform shape

Wide middle with tapered ends

Dense bodies

Analogous to the Z lines in striated muscle and They anchor the thin (actin filaments)

Smooth muscle cells

Can secrete connective tissue matrix (collagen, reticular fibres & elastin)

Hypertrophy

Increase in the size of skeletal and cardiac muscle

Hypertrophy and hyperplasia

Increases in smooth muscle