Chapter 9: Body Structure and Function

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Terms in this set (...)

artery
a blood vessel that carries blood away from the heart
capillary
a tiny blood vessel; food oxygen, and other substances pass from the capillaries into the cells
cell
the basic unit of body structure
digestion
the process of physically and chemically breaking down food so that it can be absorbed for use by the cells
hemoglobin
the substance in red blood cells that carries oxygen and gives blood its color
immunity
protection against a disease or condition; the person will not get or be affected by the deisease
menstruation
the process in which the lining of the uterus breaks up and is discharged from the body through the vagina
metabolism
the burning of food for heat and energy by the cells
organ
groups of tissues with the same fuction
peristalsis
involuntary muscle contractions in the digestive system that move food down the esophagus throught eh alimentary canal
respiration
the process of supplying the cells with oxygen and removing carbon dioxide from them
system
organs that work together to perform special functions
tissue
a group of cells with similar functions
vein
a blood vessel that returns blood to the heart.
GI
Gastro-intestinal
RBC
red blood cell
WBC
white blood cell
cells...
- are the basic unit of the body structure
- functions, size, and shape of cells are different
- need food, water, and oxygen to live and function
- are the body's building blocks
Cell structure includes...
1. cell membrane-- this is the outer covering ( it encloses the cell and helps hold its shape
2. nucleus-- this is the control center ( it directs the cell's activities and is in the center of the cell, all genetic information is here, and directs cell division/mitosis)
3. Cytoplasm-- surrounds the nucleus (also contains smaller structures that perform cell functions
4. Protoplasm-- refers to all structures, substances, and water within a cell
5. Chromosomes-- thread like structures in the nucleus (each cell has 46 chromosomes; chromosomes contain genes, genes control the traits children inherit from their parents)
Mitosis
is cell division
Cell division...
has 4 phases that result in the reproduction of cells (one cell divides to form 2 daughter cells)
Integumentary System (skin)
is the largest system and covers the body
it has epithelial, connective, and nerve tissue
has oil glands and sweat glands
Two skin layers
1. Epidermis is the outer layer
- it has living and dead cells; dead cells constantly flake off and
are replaced
- living cells replace the dead cells that flake off and contain
pigments that give skin its color
- the epidermis has no blood vessels and few nerve endings
2. Dermis is the inner layer
- it is made up of connective tissue, has blood vessels, nerves,
sweat glands, oil glands, and hair roots.

* the epidermis and dermis are supported by subcutaneous tissue
( a think layer of fat and connective tissue)*
Skin's function...
- it is the body's protective covering
- prevents microorganisms and other substances from entering the body.
- prevents excess amounts of water from leaving the body
- Nerve endings in the skin sense both plesant and unpleasant stimulation ( cold, pain, touch, and pressure to prevent the body from injury)
- helps to regulate body temperature (blood vessels dilate/widen when temperature outside the body is high, this allows more blood to be brought to the surface for cooling. blood vessels constrict/narrow when the temperature outside the body is cold, this allows the body to retain heat as less blood is brought to the surface
Musculo-skeletal system
- has 206 bones
- provides the frame work of the body
- lets the body move
- Protects and give the body shape
- has 4 types of bones
- is covered by a membrane called periosteum
- bones contain bone marrow inside their hollow centers
The 4 types of bones are..
1. Long bones - these bear teh body's weight
2. Short bones - these allow skill and ease in movement
3. Flat bones - these protect the organs
4. Irregular bones - these are the vertebrae in the spinal column, they allow various degrees of movement and flexability
Periosteum...
contains blood vessels that supply bone cells with oxygen and food
Joints...
are the points at which 2 or more bones meet. They allow movement, and there are 3 types of joints.
The three types of joints are..
1. Ball and socket
2. hinge
3. pivot
Ball and socket joints..
(found at hip and shoulder) allow movement in all directions
are made up of the rounded end of one bone and the hallow end of another bone
Hinge joint...
(elbows and knees) allow movement in one direction
Pivot joint...
(neck) allows turning from side to side
Cartilage...
(nose and ears) is the connective tissue at the end of the long bones. cushions the joint so that the bone ends do not rub together
Synovial fluid
(found in knee joint) acts as a lubricant so the joint can move smoothly
Ligaments...
are strong bands of connective tissue that hold the bones together at the joint
Muscles...
-there are more than 500 muscles.
-have 3 functions
- Strong, tough, connective tissues called tendons connect muscles to the bones.
- some constantly contract to maintain the body's posture
- when muscles contract the burn food for energy
Two types of muscles.
1. Voluntary muscles- can consciously be controlled. the muscles attached to bones or skeletal muscles. they are striated (striped or lined) looking
2. Involuntary muscles- work automatically, you can't control them. These muscles include the action of the stomach, intestines, blood vessels, and other body organs. They are smooth in appearace with out striation or streaks
Cardiac muscle...
is the heart
it is an involuntary muscle, but appears striated like skeletal muscles
The 3 functions of muscles are...
1. movement of body parts,
2. maintenance of posture
3. production of body heat (ex. shivering)
The nervous system...
- controls, directs, and coordinates body functions
Nerves...
- carry messages or impulses to and from the brain
- are easily damaged, and take a long time to heal, if they heal
- some have a protective covering called a myelin sheath
- has 2 main divisions
The 2 divisions of the nervous system are...
1. Central nervous system (consists of brain and spinal cord)
2. Peripheral nervous system (involves the nerves throughout the body
Mylein sheath
- protective covering on some of the nerves
- insulates nerve fibers
- speeds up nerve impulse conduction (thicker is quicker)
The three main parts of the central nervous system are...
1. The cerebrum
2. Cerebral cortex
3. The cerebellum
The cerebrum....
- largest part of the brain
- center of thought and intelligence
- divided into 2 halves, known as the right and left hemispheres
*the right controls the left side of the body and the left controls the right side of the body
The cerebral cortex
- is outside the cerebrum
- controls the highest functions of the brain
* reasoning, memory, speech, consciousness...
The cerebellum...
- regulates and coordinates body movements
- controls balance and the smooth movement of voluntary muscles
- injury results in jerky movements, loss of coordination, and muscle weakness
Meniges...
- consist of 3 layers of connective tissues covering the brain and spinal cord
1. Dura Matter- outer layer and lies next to the skull
2. Arachnoid- middle layer
3. Pia Matter- inner layer
Arachnoid space...
- the space between the arachnoid and pia matter
- filled with cerebrospinal fluid (would have lots of injuries without this fluid)
- protects the central nervous system
- cushions shocks that could injure the brain or spinal cord structures
Peripheral nervous system
- has 12 pairs of cranial nerves and 31 pairs of spinal nerves
*cranial nerves conduct impulses between the brain and the head, neck, chest, and abdomen.
*spinal nerves carry impulses from the skin, extremities, and the internal structures not supplied by cranial nerves
Autonomic nervous system
- divided into sympathetic and parasympathetic.
- balances each others activity
Sympathetic nervous system ...
- speeds up functions (fight or flight)
- triggered by anger, fear, excitement/anxiety, exercising
Parasympathetic nervous system..
- slows functions (rest and relaxation)