Download Tissue – Organ

Body Organization
Cell – Tissue – Organ – Organ System - Body
Tissues: Many similar cells that perform a
specific function
Tissue Types
1. Connective – Blood, Bone, Cartilage,
Ligaments, & Tendons
2. Nervous – Tissue that transmits and receives
messages or impulses (brain, spinal cord)
3. Epithelial – Skin
4. Muscle
Skeletal System
The skeletal system consists of 206 bones. At birth humans have 270 bones but many
bones fuse together during growth.
Ligaments – join bones to other bones
Cartilage - soft portion on the tips of all bones and in the nose and ears (doesn’t
contain calcium)
Skeletal System Functions
1. support
2. protection
3. produces blood cells
Bones have two parts:
Spongy bone – the soft inner portion of the bone
- yellow marrow that stores fat
- red marrow where red & white blood cells are
manufactured
Compact Bone – the hard outer portion of the bone
- contains Haversian canals which contain blood vessels
Why would there need to be blood vessels in bones?
Osteocytes (bone cells) – need oxygen and food for
energy
Development of Bones
In the second month of development bone starts to form where before the embryo had only a
cartilage skeleton
Ossification – is the process of cartilage turning into bone
Epiphyseal plate is a layer of cartilage found at the end of each bone where growth takes place.
Cells in this area undergo mitosis
Divisions of these cells cause the cartilage to grow and the bones to lengthen as the bone cells
ossify
Growth stops when these cells stop dividing
Bones continue to grow in width throughout life growth in length stops at 25 if not sooner.
Joints
The place where bones meet is a joint
Joints can be movable and immovable
Where are immovable joints?
Four major types of joints:
1. Hinge – elbow, knee, and ankle
2. Pivot – neck
3. Ball-and-socket – hip and shoulder
4. Gliding – carpal and tarsal bones
Cartilage and synovial fluid (the WD-40 of your
body) keep joints moving smoothly
Skeletal System problems
Sprain – A stretch or tear of a ligament
Arthritis – when joints become swollen or painful
Rheumatoid arthritis – cartilage
becomes swollen. Eventually it is
replaced by bone, which fuses and
prevents movement
Osteoarthritis – when cartilage wears
away and bones rub together
Osteoporosis – a person loses bone
density (usually begins around 40)
More common in women because
they lose their ability to absorb
Calcium efficiently when they have
children
THANK YOU MOM!!
The Muscle System
The body has more than 600 muscles (35-45% of body weight)
Functions of Muscle System
1. Movement – main function
2. Digestion, Breathing, Heart Beating etc
3. Protection of internal organs
4. Sitting & Standing
Muscles only pull a bone
Muscles CANNOT push a bone
This is why muscles act in pairs
One muscle to extend
One muscle to bend
Muscle Types
1. Skeletal Muscles – move bones attached directly to bones or by a tendon
2. Smooth Muscle – found in internal organs (digestive tract, arteries, respiratory
system)
3. Cardiac Muscle – heart muscle
Smooth and Cardiac are both involuntary
What does involuntary mean?
How Muscles Contract:
1. A nerve impulse transmitted to the muscle cell by a nerve.
2. The nerve releases Calcium into the cytoplasm of the muscle cell
3. Calcium attaches to molecules located in the cytoplasm called actin
(protein)
4. ATP connects to myosin (protein)
What does ATP do?
5. Using the energy
from the ATP the
myosin (protein) pulls
the actin & the muscle
contracts
6. When the message
from the brain ends the
Calcium leaves and
the muscle relaxes
Exercise
With aerobic exercise, chest muscles can be strengthened so that more air
enters the body. This type of exercise helps your cardiovascular endurance.
Why would this help?
Resistance (anaerobic) exercise like weight lifting increases muscle
size and strength but it does not increase the amount of oxygen that
enters the body.
Anabolic steroids increase the size and strength of your muscles, synthetic chemicals
(that resemble testosterone) trick your muscles into growing larger. They also cause
many irreversible side effects including cancer, heart disease, and altered sexual
development.
Muscle Problems
Shin Splints – inflammation of the tendons on the inside front of the
lower leg, muscle strain , overuse injury
Muscle Cramps – occurs when a muscle cannot relax
Muscular Dystrophy – muscle tissue degenerates and
is replaced by fatty tissue
Integumentary System
Covers the body
Made up of the skin, hair, nails, & a variety of glands
The Skin is the human body's largest organ
The most important function is protection.
Endocrine System
Controls the body through hormones
Example
The hormone melatonin, which
secreted by a gland in the brain
called the pineal gland, is secreted at
night when light is absent or dim.
Melatonin is what makes us feel
tired