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HUMAN SYSTEMS
CHAPTERS 35-40
SKELETAL SYSTEM
Includes bones and their associated
tissues -- cartilage, tendons and ligaments
make up the skeletal system
Bones are a solid network of living cells
and fibers supported by deposits of
calcium salts
See picture of the skeleton pg. 922 of
your Biology book
FUNCTIONS OF THE
SKELETAL SYSTEM:
1. Support and shape the body -- without
it the body would collapse
2. Protect delicate organs ex. Cranium
forms shell around the brain
3. Bones are site of blood-cell formation
and they store minerals
4. Anchors muscles and helps in
movement
SKELETAL SYSTEM
Many bones are formed from
connective tissue called
cartilage; cartilage can
support some weight, but it
is extremely flexible
Ex. Bones of a newborn baby
Ossification - process of
replacing cartilage with bone
In adults, cartilage is found
in ears, tip of nose, etc.
SKELETAL SYSTEM
Joints - where two bones meet to allow the
body to move
TYPES OF JOINTS:
1. Immovable – fixed (cannot move)
Ex. Skull
2. Slightly movable – small amount of restricted
movement
Ex. 2 bones of the lower leg, vertebrae
3. Freely movable – permits movement in one
or more directions
Types of Freely Movable Joints
1. Ball-and-Socket – widest range of
movement
Ex. Shoulder, hip
2. Hinge – back and forth movement
Ex. Elbow, knee, fingers
3. Pivot – one bone rotates around another
Ex. Lower arm (ulna and radius)
4. Saddle – one bone slides in 2 directions
Ex. thumb
SKELETAL SYSTEM
ASSOCIATED TISSUES:
1. Cartilage - serves as a
cushion between
bones; supports
weight
2. Ligament - connects
bone to bone
3. Tendon - connects
muscle to bone
INTEGUMENTARY SYSTEM
Includes skin and all accessory organs - hair,
nails and a variety of glands (sweat and oil);
single largest organ in the body
FUNCTIONS:
1. Protection - most important function;
especially from ultraviolet radiation
2. Regulate body temperature
3. Remove wastes from the body
4. Barrier against infection and injury
INTEGUMENTARY SYSTEM
Skin is composed of two MAIN layers:
1. Epidermis - outermost cells of skin;
undergo rapid cell division (mitosis)
2. Dermis - inner layer of skin; contains
blood vessels, nerve endings, glands, sense
organs, smooth muscle and hair follicles
3. Hypodermis - below the dermis (layer of
fat and connective tissue); not a main layer
INTEGUMENTARY SYSTEM
ACCESSORY ORGANS:
1. Hair - produced by cells at base of hair
follicle; used for protection and warmth
2. Nails - grow from nail root located near
tip of fingers and toes; for protection
3. Sweat/Oil Glands - sweat glands regulate body temperature and remove
wastes; oil glands - keeps skin flexible
and waterproof
MUSCULAR SYSTEM
The job of the
muscular system is to
move the skeletal
system. It is
composed of muscle
tissue that is highly
specialized and able
to contract (shorten)
when stimulated.
MUSCULAR SYSTEM
THREE TYPES OF MUSCLES:
1. Skeletal: attached to bone; at work every
time we lift a finger, wink, chew and run;
appear STRIATED (striped); Voluntary
2. Smooth: Involuntary; not striated; contract
without us thinking about it; found in
Internal organs (stomach, blood vessels,
intestines)
3. Cardiac: only found in the heart; striated;
Involuntary (don’t think about it)
CIRCULATORY SYSTEM
Made up of blood, the heart, blood vessels
The heart is a hollow, muscular organ that
contracts at regular intervals; it can be thought of
as two pumps sitting side by side
The two pumps are separated by a SEPTUM
Each pump is divided into two chambers:
The upper chambers are called ATRIA (receive
blood)
The lower chambers are VENTRICLES (pump
blood out)
CIRCULATORY SYSTEM
The right side of the heart
pumps blood from the body into
the lungs where oxygen-poor
(deoxygenated) blood gives up
carbon dioxide and picks up
oxygen
The left side of the heart pumps
oxygen-rich (oxygenated) blood
from the lungs to the rest of the
body
CIRCULATORY SYSTEM
BLOOD VESSELS:
1. Arteries - carry blood away from the
heart to all tissues of the body; the
largest artery is the AORTA
2. Capillaries - only one cell thick making
diffusion of oxygen and nutrients easy
3. Veins - collect blood and return it
back to the heart
CIRCULATORY SYSTEM
FUNCTIONS OF BLOOD:
1. Transports nutrients,
dissolved gases, enzymes,
hormones and waste products
2. Regulates body
temperature, pH and
electrolytes
3. Protects body from invaders
4. Restricts loss of fluid
CIRCULATORY SYSTEM
COMPONENTS OF BLOOD:
1. Plasma: liquid portion of blood that contains
water, dissolved fats, salts, sugars and proteins
2. Red blood cells (erythrocytes): transport
oxygen
3. White blood cells (leukocytes): protect body
against invasion by foreign cells or substances
4. Platelets: responsible for the clotting of
blood
Lymphatic System
Network of vessels, nodes and
organs
Collects the fluid that is lost by
the blood and returns it back to
the circulatory system
The fluid is known as lymph
RESPIRATORY SYSTEM
Consists of the nose, pharynx, larynx,
trachea, bronchi and lungs
Function is to bring about the exchange of
oxygen and carbon dioxide between the
blood, the air and the tissues
FLOW OF AIR: Air enters NOSE --> pharynx
OR enters MOUTH --> pharynx; after
pharynx ---> larynx (top of trachea) -->
trachea (windpipe) --> to left or right
bronchi ---> bronchioles --> alveoli
RESPIRATORY SYSTEM
BREATHING:
Inhalation: pulling of air into lungs
Exhalation: pushing of air out of
lungs
Diaphragm: Located along the
bottom of the rib cage; it is the large
flat muscle responsible for inhalation
and exhalation
RESPIRATORY SYSTEM
The alveoli is where gas exchange
occurs
When blood enters the lung it has
a lot of carbon dioxide and a low
oxygen content, but the alveoli are
filled with fresh oxygen-rich
inhaled air
Carbon dioxide diffuses out of the
blood into the alveoli and oxygen
diffuses into the blood from the
alveoli
DIGESTIVE SYSTEM
Includes mouth, pharynx, esophagus,
stomach, small intestine and large
intestine; several major glands add their
secretions, including the salivary glands,
the pancreas and the liver
Digestion is the breakdown of food into
simpler molecules that can be absorbed
and used by the cells of the body
DIGESTIVE SYSTEM
THE PROCESS OF DIGESTION:
1. Mouth - teeth break up food in a process
called mechanical digestion; also salivary glands
secrete the first digestive enzymes (amylase and
mucous)
2. Pharynx - the top part of the throat; no
digestion takes place here
3. Esophagus - the muscles of the esophagus
begin to contract in waves, pushing food toward
the stomach; this is called peristalsis
DIGESTIVE SYSTEM
4. Stomach - three secretions combine to
form the gastric fluid:
Mucous - keeps food lubricated and
protects walls of the stomach
Hydrochloric acid - helps break down food
Pepsin - mixes with hydrochloric acid to
begin digesting proteins
The food is churned for several hours
becoming a pasty mixture known as chyme
DIGESTIVE SYSTEM
5. Small Intestine - the chyme is flooded
with enzymes from three sources:
Duodenum (1st part of small intestine) releases enzymes that continue digesting
Pancreas - releases pancreatic fluid that
digests carbohydrates, proteins and fats
Liver - secretes bile, which is stored in the
gallbladder, which breaks down fats further
DIGESTIVE SYSTEM
5. Small Intestine - the now mostly
digested food passes through the rest of
the small intestine where nutrients are
absorbed into the bloodstream; when it
leaves the s.i., the food is nutrient free
6. Large Intestine (Colon) - main job is to
remove water from undigested materials
passing through it
Excretory System
Consists of kidneys, ureters, urinary
bladder, urethra
Eliminates waste products from the
body in ways that maintain
homeostasis
Kidneys remove waste products from
the blood, maintain blood pH and
regulate the water content of the
blood
Endocrine System
Consists of the glands that release
their products (hormones) into the
bloodstream
These products deliver messages
throughout the body
Hormones – chemicals released in
one part of the body that affect the
activities of cells in other parts of the
body
Endocrine System
Types of Glands:
1. Pituitary – secretes 9 hormones that
regulate many body functions
2. Hypothalamus – controls secretions of
the pituitary
3. Thyroid – regulates the body’s
metabolism
4. Parathyroid – works with thyroid to
maintain homeostasis of calcium levels in
blood
Endocrine System
Types of Glands:
5. Adrenal – releases hormones that
help the body prepare for and deal
with stress
6. Pancreas – helps maintain blood
sugar levels
7. Reproductive Glands – ovaries in
females; testes in males
Nervous System
Controls and coordinates functions
throughout the body and responds to
internal and external stimuli
Neurons – cells that transmit the signals
(impulses)
2 Divisions of the Nervous System:
1. Central Nervous System
2. Peripheral Nervous System
Nervous System
1. Central Nervous System
Consists of the brain and spinal cord
Relays messages, processes information and
analyzes information
2. Peripheral Nervous System
Consists of all the nerves and cells not part of
the brain and spinal cord
Transmits impulses from sense organs to the
central nervous system
Transmits impulses from the central nervous
system to muscles or glands
Immune System
Fights infection through the
production of cells that inactivate
foreign substances or cells
White blood cells are an important
part of the immune system – they
attack and fight off the infection
Reproductive System
Consists of testes, urethra and penis for
males
Consists of ovaries, Fallopian tubes,
uterus and vagina for females
Produces reproductive cells (sperm and
egg)
In females, the uterus nurtures and
protects the developing embryo