Transcript Smooth Muscle

Human Skeletal & Muscle
Systems
Structures, Functions, and
Examples
Body Orientation
Ventral--front of the body
Dorsal--back of body
Lateral--side of body
Medial--middle of body
Cranial--head region
Caudal--feet region
Proximal--toward the trunk
Distal--away from the trunk
Major Body Cavities
Dorsal
– Cranial (skull)
– Spinal
Ventral
– Abdominal
– Pelvic
– Thoracic (chest)
Skeletal System—Functions
Support-framework for the body
Movement-site for muscle attachment
Protection-cover brain, spinal cord, lungs,
etc.
Mineral & lipid (type of fat) storage-yellow
marrow contains Ca (calcium), P
(phosphorous), and lipids
Hemopoiesis-red marrow makes blood
cells (red, white, macrophages, platelets,
etc.)
Bone Formation
Very controlled process of converting
embryonic connective tissue into bone.
Process is called ossification.
Process of ossification occurs throughout
life however, it is more rapid in younger
years.
Process of bone formation can be altered
with destructive life styles.
Process of bone formation is under control
of many vitamins and hormones.
Skeletal System-Specific Bones
Skull—head
Shoulder—scapula, clavicle
Arm—humerus, radius, ulna, metacarpals,
phallanges
Chest—ribs, sternum, xiphoid process
Spine—cervical, thoracic, lumbar, sacral,
coccyx
Hips—pelvis
Skeletal System-Specific Bones
Leg—femur, tibia, fibula, metatarsals,
phallanges
Other Components of
Skeletal System
Cartilage—firm flexible connective tissue
that comprises the infant skeletal system;
gradually gets replaced by bone; adult
cartilage examples include nose and top of
ear.
Ligament—tough, flexible, and fibrous
connective tissue linking bone to bone.
Muscle Types
Skeletal muscle—moves bones directly
or indirectly; voluntarily controlled;
banded
Cardiac muscle—pumps blood through
body; involuntarily controlled; banded
Smooth muscle—moves materials
through structures; involuntarily
controlled; not banded; examples where
smooth muscle is found include
arteries, intestines, stomach, and
esophagus
How Muscle Functions
Nerves control the muscle tissue
Requires the use of ATP and calcium
for energy
Uses two types of filaments (Actin and
Myosin) for contraction and relaxation
Needs aerobic conditions to function
Excess muscle use leads to anaerobic
conditions resulting in cramping
Muscle Shape and Architecture
Flat
Pennate (leaf-like)
Fusiform
Quadrate
Circular or Sphincteral
Skeletal Muscles of
Arm Movement
Biceps—bends arm at elbow proximally to
cranial area
Triceps—bends arm at elbow distally from
cranial area
Deltoid—moves arm at shoulder (clavicle
and scapula)
Pectoralis major—moves arms forward
Trapezius—moves arms backward
Cardiac Muscle
Strongly regulated by nerve bundles to
control rhythm of heart beat
Irregular heart beats can be regulated by a
pacemaker
Sudden stoppage of the normal heartbeat
can sometimes be restarted by electric
shock (defibrillator)
Electrocardiogram is the measure of the
electrical impulses in the heart
Smooth Muscle
Involuntary muscle controls variety of
tissues or organs
Digestive tract has number of examples of
smooth muscle (stomach, intestines,
esophagus
Smooth muscle of arteries act to pump
blood throughout the body
End of Skeletal and
Muscle Systems