Lec Int 3-4 Flashcards
serve to contract and relax
Muscles
serve to support the skeleton and its articulations
skeletal muscles
Muscle tissue consists of three major structural types
Smooth, cardiac, skeletal
Type of muscle that lines walls of hollow viscera (GI tract, blood vessels)
amooth
Type of muscle with inherent contractility. No innervation is needed, except for regulation of rate, contractile strength
cardiac
40% of the body mass in normal adults and is the type of muscle attached to the skeleton for moving and supporting joints
Skeletal
Innervation of smooth muscle is via the _________ nervous system
autonomic
Muscles pull ______ (and hence move) a joint
across
A muscle may contract up to ______% of its resting length
57%
4 types of muscular action
Prime mover, Synergists, Fixators, Antagonists
certain muscles whose main function is to produce a specific action.
Prime mover
assist the prime mover, and compliment its action
Synergists
immobilize a joint while another joint is activated
Fixators
stabilize a joint while the opposite prime movers are contracting (eg flexors/extensors)
Antagonists
a muscle fiber equals a ______
muscle cell
Type of mucleation of muscle cells
multinucleated
Term for nuclei located at the periphery of the fiber
syncytial arrangement
The whole sheath around a muscle is called the
epimysium
The epimysium is synonymous with the
deep fascia
connective tissue holding the muscle fibers together
deep fascia
The deep fascia, or epimysium, consists of
collagenous fibers
To cause a joint to move, a muscle must attach to bones around the respective joint. Such attachments are accomplished via relatively avascular structures called
tendons
Tendons are formed by an aggregation of the ________
sarcolemma
the cell membrane surrounding the muscle fibers
sarcolemma
The sarcolemmae are continuous with ______ of a tendon
collagenous fibers
tendon is continuous with _______ of bone, and, in some cases, the joint capsule
periosteum
attachment of muscles to each other (flat sheet of connective tissue)
Aponeurosis
Two examples of aponeuroses
linea alba and bicipital aponeurosis
Muscles vs tendons vascularization?
Vascular, avascular
The featherlike appearance of muscles is referred to as
pennate
muscle fibers approach tendon from one side (palmar interossei)
Unipennate
muscle fibers approach tendon from 2 directions in a flat plane (dorsal interossei)
Bipennate
muscle fibers approach tendon from all directions (biceps brachii)
Circumpennate
multiples of all the above described pennate forms (deltoid)
Multipennate
sensory aspect of input into the nervous system regarding the status of a muscle at any given time
Proprioception
Degree of contraction of muscles
State of tension in the tendon
Position of limbs in space
Three forms of proprioception for muscles
support of the body
movement (levers)
blood producers (from red bone marrow)
storage (Ca++, PO4)
Bones
The skeleton may be divided into two portions
axial and appendicular
consists of the skull, spine, and thorax
axial
consists of the upper/lower limbs
appendicular
Together, the two skeletons have ____ bones in all
206 bones
Five types of bone by shape
A. Long: humerus, femur (examples) B. Short: carpals, tarsals (examples) C. Flat: cranium (example) D. Sesamoid: patella (example) E. Wormian: in sutures of the skull (example) F. Irregular: vertebrae (example)
Bone develops from two basic sources:
Intramembranous ossification, Endochondral ossification
Type of bone development in which a fibrous membrane, which forms intramembranous bone, as typified by the bones of the skull
Intramembranous ossification
Type of bone development from cartilage, which forms endochondral bone as typified by the long bones
Endochondral ossification
Describe intramembranous ossification
- Start with dense membrane
- Osteoblasts produce osteod tissue, add Ca and PO4
- Periosteum surrounds dense membrane, osteoblasts form inner surface of matrix
Type of bone in with random matrix with soft, open spaces which forms the interior of the bone
Spongy bone
Type of bone with parallel matrix which is hard and dense, that forms the exterior surface of the bone
Compact bone
Externally and next to the periosteum, the layer of compact bone is called the
outer table
internally (deep to the spongy bone (in compact bone), the bony layer is called the
inner table
Describe endochondral ossification
- A cartilaginous mold of the bone forms initially in the developing embryo
- Osteoblasts lay down osteod, Ca and PO4 added
- Gradually, cartilage is replaced by bone
In endochondral ossification, cartilage persists at the ends of the bone as ______
epiphyseal plates
Epiphyseal plates persist until the bone reaches its adult length, then close to form _____
epiphyseal lines
a form of dwarfism that is caused by a mutation in fibroblast growth factor receptor 3 (FGFR3).
Achondroplasia
the granular material found within the spongy portion of bones which form blood cells is called the
bone marrow
In small children, virtually all marrow is
red
In adults, bone marrow is identified as
red, yellow
sternum, ribs
iliac crest
vertebral bodies
locations of Red Marrow
long bones - nonfunctional, fatty tissue and has replaced red marrow to occupy the “marrow cavity.”
locations of yellow marrow
