Cell Specialization

Cell structure and function

Cell Specialization

• Specific cells are uniquely suited to carry out specific functions, some specific types of cells are listed below:

Neurons • These are cells

that are part of the nervous system, they are message carrying cells

• They are among the longest and thinnest cells in the body

Macrophages• Provide protection,

travel in the bloodstream

• At the site of a wound or infection, macrophages appear in great numbers and begin to disarm the bacteria and other invading organisms.

Red Blood Cells• A single drop of blood contains

millions or red blood cells constantly traveling through the body delivering oxygen and removing waste

• RBCs are red because they contain a protein called hemoglobin (bright red in color)

• Hemoglobin contains iron, an excellent vehicle for transporting oxygen and carbon dioxide

• The RBCs get worn out and eventually die

• The average life cycle of a red blood cell is 120 days

• Your bones are always producing new blood cells

• If sudden blood loss occurs, the platelets kick into action• Platelets are irregularly – shaped colorless bodies in blood• Sticky surface lets them form clots

Stem Cells

• Scientists primarily work with two kinds of stem cells from animals and humans:– Embryonic stem cells– Adult stem cells

Embryonic Stem Cells

• In the 3 to 5 day old embryo – a blastocyst, a small group of about 30 cells gives rise to the hundreds of highly specialized cells needed to make up an adult organism

Adult, or somatic, stem cells

• In some adult tissue, such as bone marrow, muscle, skin, liver, and brain, populations of adult stem cells replace cells lost through normal wear and tear, injury or disease

Stem cells

https://www.youtube.com/watch?v=KNkQtc7TM6M&feature=em-share_video_user

Epithelial Cells form Epithelial Tissue

• Structure:– Epithelial Cells pack tightly together and form

continuous sheets that line different parts of the body.• Function:

– Protection, secretion, absorption, and transport• Examples:

– Inside the mouth (cheek cells) – Line organs like the stomach– Surround the outside of organs– Make the outer layer of skin

MUSCLE TISSUE• Structure:

– Muscle cells make specialized tissue that can contract. – Muscle tissue contains the specialized proteins actin

and myosin that slide past one another.• Function:

– Allows for movement of limbs and contraction.• Examples:

– Heart – Cardiac Muscle– Body Movement—Skeletal Muscle– Digestive Tract, Veins/Arteries, Bladder—Smooth

Muscle

NERVE TISSUE• Structure:

– Elongated cells with many branches.• Function:

– Has the ability to generate and conduct electrical signals in the body.

– These signals are managed by the brain and transmitted down the spinal cord to the body.

White Blood Cell

• Structure:– Large, flexible cells– Covered in proteins that recognize invaders.

• Function:– Part of your immune system.– Fight off bacteria and other invaders.

• Examples:– Neutrophils – engulf bacteria– Basophil – Release histamine to promote and

inflammatory response.

Red Blood Cell

• Structure:– Round, disc-shaped cell– Concave center

• Function:– Transport oxygen

throughout the body.

Plant Leaf vs. Plant Stem• Leaf

– Contains Guard Cells that open and close to allow for gas exchange

– Lined with Chloroplasts

• Stem– Contain Xylem and Phloem that carry food and

water up the stem of the plant.