Transcript Muscular System - Cloudfront.net

Tissues of the skin
epidermis- squamous
epithelium; basement
membrane
dermis- largely
connective tissue;
many nerves and
blood vessels;
smooth muscle
hypodermis (NOT part
of skin) - adipose
tissue and more loose
connective tissue
Roles
•protection
•maintenance of body
temperature
•storage of fat
•synthesis of vitamin D
•excretion of salts, water
and wastes in sweat
•sensory perception
Accessory structures
Hair Follicle - Originate
in epidermis, extend
into dermis; muscle
attached
Hair is pigmented;
determined by amount
of melanin, pigment
production decreases
with age
Two types of exocrine glands
Sebaceous- sebum (oil, wax)
associated with hair follicles
helps maintain pliability of skin
Sweat glands
apocrine (armpits, groin)
Melanin
•
•
•
•
•
Protects against UV
Use UV -> VitaminD
One hour/week
Protects DNA
More UV -> more
melanin -> tan
Nails
Nail bed overlaid by nail plate
Nail growth originates from
root; cells become keratinized
The Skeletal System
 Parts of the skeletal system
 Bones (skeleton)
 Joints
 Cartilages
 Ligaments (bone to bone)(tendon=bone to muscle)
 Divided into two divisions
 Axial skeleton
 Appendicular skeleton – limbs and girdle
a.
Axial: skull,
backbone, ribs,
sternum
a.
Appendicular:
arms, legs,
shoulders,
hips,wrists,
ankles
Classification of Bones on the Basis of Shape
The Skull
 Two sets of bones
 Cranium
 Facial bones
 Bones are joined by sutures
 Only the mandible is
attached by a freely
movable joint
Slide
The Vertebral Column
 Vertebrae separated by
intervertebral discs
 The spine has a normal
curvature
 Each vertebrae is given a
name according to its
location
Slide 5.28
The Bony Thorax
 Forms a cage to
protect major
organs
 Made-up of three
parts
 Sternum
 Ribs
 Thoracic
vertebrae
Figure 5.19a
Slide
The Pectoral (Shoulder) Girdle
 Composed of
two bones
 Clavicle –
collarbone
 Scapula –
shoulder blade
Slide 5.33
Bones of the Upper Limb
 The arm is formed by
a single bone
 Humerus
Figure 5.21a, b
Slide
Bones of the Upper Limb
• The forearm has two
bones
• Ulna
• Radius
Figure 5.21c
Slide
Bones of the Upper Limb
 The hand
 Carpals – wrist
 Metacarpals – palm
 Phalanges – fingers
Figure 5.22
Slide 5.36
Bones of the Lower Limbs
 The thigh has one
bone
 Femur – thigh bone
Slide
Bones of the Lower Limbs
 The leg has two bones
 Tibia
 Fibula
Slide
Bones of the Lower Limbs
 The foot
 Tarsus – ankle
 Metatarsals – sole
 Phalanges – toes
Figure 5.25
BONE FRACTURES
 A break in a bone
 Types of bone fractures
 Closed (simple) fracture –
break that does not
penetrate the skin
 Open (compound) fracture –
broken bone penetrates
through the skin
 Bone fractures are treated by
reduction and immobilization
 Realignment of the bone
Types of joints
• Gliding joints, the
articulating surfaces are
typically flat
• Hinge joints, found in the
fingers and elbow; the
spoon-like surface fits into
a concave surface
• Ball and socket, shoulder
joint; where a ball fits into a
cuplike depression
• Pivot joints, found between
the proximal ends of the
radius and ulna; surface fits
Joint Damage: Arthritis
Muscular System
• Muscles are responsible
for all types of body
movement
• Your body has more than
600 muscles
• Three basic muscle types
– Skeletal muscle
– Cardiac muscle
– Smooth muscle
Skeletal Muscle Characteristics
• Most are attached by tendons to
bones
• Cells are multinucleate
• Striated – have visible banding
• Voluntary – subject to conscious
control
Functions of Skeletal Muscle
–
–
–
–
Produce movement
Maintain posture
Stabilize joints
Generate heat
• Sites of muscle
attachment
– Bones
– Cartilages
– Connective tissue
coverings
Action of Skeletal Muscle
– Muscles do work only by contracting
– In order for muscles to cause any kind of movement,
they must work in pairs
– When one contracts, the other relaxes
Smooth Muscle
• Help control breathing,
blood pressure, and the
movements of the
digestive system
• Has no bands - hence
the name
Characteristics of Smooth Muscle
•
•
•
•
Has no striations
Spindle-shaped cells
Single nucleus
Involuntary – no
conscious control
• Found mainly in the walls
of hollow organs
Cardiac Muscle
– Found only in the
heart
• Branches out in
many directions,
weaving a complex
mesh
• Contractions of
cardiac muscle cause
the heart to beat
Cardiac Muscle Characteristics
• Has striations
• Usually has a single
nucleus
• Joined to another muscle
cell at an intercalated disc
• Involuntary
• Found only in the heart
Naming Skeletal Muscle – by Location
– Structure near which
a muscle is found
– Muscle near frontal
bone = Frontalis
– Muscle near the Tibia
= Tibialis anterior
Naming Skeletal Muscle – by Size
– MAXIMUS means
largest
• Gluteus Maximus
– MINIMUS means
smallest
• Gluteus Minimus
– LONGUS means longest
• Fibularis Longus
– BREVIS means short
• Fibularis Brevis
– TERTIUS means
shortest
• Fibularis Tertius
Naming Skeletal Muscle - by number of Origins
• Number of tendons of
origin
– BICEPS means two
• Biceps Brachii
– TRICEPS means three
• Triceps Brachii
– QUADRICEPS means
four
• Quadriceps
Femoris