Human Anatomy

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Human Anatomy
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The Brain
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The Brain

• Organization of the Nervous System
• The nervous system includes two major divisions.
• The first division is the central nervous system
  and is made up of the brain and the spinal cord.
• The brain is the control center of the nervous
  system.
• The spinal cord carries nerve signals between the
  body and the brain.

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The Brain

• Structure of the Human Brain

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The Brain

• Organization of the Nervous System
• The second division is the peripheral nervous
  system and consists of neurons that have cell
  bodies and that are not included in the brain and
  spinal cord.
• Peripheral neurons send information to and from
  the central nervous system.

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The Brain

• Brain
• FPOT

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The Circulatory System
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• Circulatory System
• Transportation system by which oxygen and
  nutrients reach the body's cells, and waste
  materials are carried away.
• Also carries substances called hormones, which
  control body processes, and antibodies to fight
  invading germs.

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Parts of the Circulatory System

• Divided into three major parts
• The Heart
• The Blood
• The Blood Vessels

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• The Circulatory System
• The heart, the lungs, and the blood vessels work
  together to form the circle part of the
  circulatory system.

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Circulation

• Blood travels from the right ventricle through
  arteries to lungs where it gets fresh oxygen and
  becomes bright red
• Blood from lungs through the veins back to the
  heart's left ventricle.
• Pumped out into the body

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The Heart

• Control of the Heartbeat
• A heartbeat has two phases.
• Phase one is called systole and occurs when the
  ventricles
• Phase two is called diastole and occurs when the
  ventricles relax

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The Heart

• Control of the Heartbeat (cont.)
• A series of pressure waves are caused by the
  contractions of the left ventricle when it forces
  blood through the arteries. This is called a
  pulse.

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Blood Vessels

• Three Kinds of Blood Vessels
• Arteries
• Veins
• Capillaries

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Arteries

• Carry blood AWAY from the heart
• Each region of your body has system of arteries
  supplying it with fresh, oxygen-rich blood.
• Tough on the outside
• Smooth on the inside
• Muscular wall helps the heart pump blood

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Have strong, muscular walls The inner layer is
very smooth so that the blood can flow easily
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Capillaries

• Very thin
• Only one cell thick
• Connect arteries veins
• Food and oxygen released to the body cells
• Carbon dioxide and other waste products returned
  to the bloodstream

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Capillaries
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Veins

• Veins
• Carry blood to the heart
• Receive blood from the capillaries
• Transport waste-rich/ oxygen-poor blood back to
  the lungs and heart
• Valves are located inside the veins
• Allow blood to move in one direction

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Valves are located inside the veins. The valves
only allow blood to move in one direction.
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Arteries Blood Pressure

• Blood Pressure
• As the heart moves the blood through the
  arteries, it produces a great force against the
  inside walls of a blood vessel. This force is
  known as blood pressure.
• High blood pressure, or hypertension, can place a
  strain on the walls of the arteries and could
  cause that artery to burst.

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Arteries Blood Pressure

• Blood Pressure
• In order to measure blood pressure, systolic
  pressure and diastolic pressure must be measured.
• Systolic pressure, measured first, is the
  pressure of the blood when the ventricles
  contract.
• Diastolic pressure, measured second, indicates
  the steady flow of blood through the artery.

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Arteries Blood Pressure

• Blood Pressure
• Normal blood pressure 120/80
• Fluctuates based on activity level, age and
  health.
• Hypertension consistently high blood pressure.

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Arteries Blood Pressure

• Factors Affecting Blood Pressure
• Volume
• Viscosity refers to the thickness of the blood.
  This thickness is caused by the number of red
  blood cells. Thick blood travels through the
  blood vessels at a slower rate than thin blood
  and can increase the resistance to flow,
  affecting the rateof blood flow in the arteries
• Resistance
• Exercise
• Disease

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Arteries Blood Pressure

• Factors Affecting Blood Pressure
• Atherosclerosis A disease in which plaque
  builds up inside your arteries.
• Plaque is made up of fat, cholesterol, calcium,
  and other substances found in the blood. Over
  time, plaque hardens and narrows your arteries
• Can lead to serious problems, including heart
  attacks, strokes, or even death.

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Composition of Blood

• Blood
• Pumped by your heart.
• Travels through thousands of miles of blood
  vessels
• Carries nutrients, water, oxygen and waste
  products to and from your body cells.
• Made up of liquids, solids and small amounts of
  oxygen and carbon dioxide.

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Composition of Blood

• Red Blood Cells (Erythrocytes)
• Red blood cells carry oxygen from the lungs to
  all the cells of the body.
• Takes carbon dioxide and transports it back to
  the lungs.
• About 5,000,000 Red Blood Cells in ONE drop of
  blood.

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Composition of Blood
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Composition of Blood

• White Blood Cells (Lymphocytes)
• White blood cells protect the body from germs
• Attack and destroy bacteria, viruses, and toxic
  proteins and help the body develop immunities.
• There are several types of white blood cells,
  including phagocytes and antibodies.
• Phagocytes are cells that engulf and digest
  foreign matter or microorganisms.
• Antibodies are proteins that react to a specific
  type of invader or inactivate or destroy toxins.

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Immune System
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Immune System

• Identifying Pathogens
• A pathogen is any agent that causes disease and
  can be spread to humans through the air, food,
  water, or direct contact with an infected animal
  or person.
• A disease that is caused by a pathogenic
  bacteria, virus, fungi, or protist is called an
  infectious disease.

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Immune System Nonspecific Defenses

• First Line of Defense Barriers
• Nonspecific defenses, such as the skin and mucous
  membranes, are barriers to potential pathogens.
• In addition to being a physical barrier to
  pathogens, skin also produces sweat, oils, and
  waxes, which are toxic to many bacteria.
• A mucous membrane is a layer of epithelial tissue
  that covers internal surfaces of the body and
  secretes mucus, a sticky fluid that traps
  pathogens.

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Immune System Nonspecific Defenses

• Second Line of Defense Nonspecific Immunity
• If a pathogen gets past the skin and the mucous
  membranes, the body triggers the second line of
  defense, which is nonspecific immunity.
• Nonspecific immunity works in the same way
  against any pathogen.
• Nonspecific immunity includes the inflammatory
  response, and the temperature response.

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Immune System Nonspecific Defenses

• Second Line of Defense Nonspecific Immunity
  (cont.)
• Inflammatory Response
• An inflammatory response is a series of events
  that suppress infection and speed recovery.
• When cells are damaged they release chemical
  messengers, such as histamine.
• Histamine is a substance that increases blood
  flow to the injured area and increases the
  permeability of surrounding capillaries.

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Immune System Nonspecific Defenses

• Second Line of Defense Nonspecific Immunity
  (cont.)
• Inflammatory Response (cont.)
• Fluids and white blood cells called phagocytes
  leak through capillary walls to fight any
  pathogens that may have entered the body.
• Phagocytes are cells that ingest and destroy
  foreign matter, such as microorganisms.

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Immune System Nonspecific Defenses
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Immune System Nonspecific Defenses

• Second Line of Defense Nonspecific Immunity
  (cont.)
• Temperature Response
• When the body begins to fight pathogens, body
  temperature may increase. This rise in
  temperature is called a fever.
• The body triggers a fever in order to slow
  bacterial growth or to promote white blood cell
  activity.
• Though a moderate fever can be helpful, high
  fevers can be dangerous.

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Immune System Specific Defenses

• Second Line of Defense The Immune System
• The Immune System
• The immune system includes the cells and tissues
  that recognize and attack foreign substances in
  the body.
• The components of the immune system are found
  throughout the body.

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Immune System Specific Defenses

• The Immune System (cont.)
• Bone marrow, the thymus, lymph nodes, the spleen,
  adenoids, and tonsils are all part of the immune
  system.
• Each part of the immune system plays a special
  role in defending the body against pathogens.
• The specialized cells of the immune system are
  called lymphocytes. Lymphocytes are white blood
  cells that exists in two primary forms T and B
  cells.

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Immune System Specific Defenses

• The Immune System (cont.)
• B cells are white blood cells that are made in
  the bone marrow and complete their development
  there or in the spleen. B cells make antibodies.
• T cells are cells that are made in the bone
  marrow but complete their development only after
  traveling to the thymus. T cells also participate
  in many immune reactions.

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Immune System Specific Defenses

• Immune Response
• Antigens are foreign substances that can trigger
  an immune response.
• Antibodies are defensive proteins that react to
  a specific antigen or inactivate or indirectly
  destroy toxins.
• Uses various methods to disable a pathogen or
  cause its destruction.

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Immune System Specific Defenses

• Immune Response
• The immune system reacts to antigens by
  increasing the number of white blood cells that
  attack the invader or by producing antibodies.

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Immune System Specific Defenses

• Immune Response
• Primary Secondary Immune Responses
• The first time the body encounters an antigen,
  the immune response is called a primary immune
  response.
• During this first encounter, the immune system
  fights off the disease. After the disease is
  overcome, the immune system creates memory cells.

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Immune System Specific Defenses

• Immune Response
• Primary Secondary Immune Responses (cont.)
• The second time the body encounters an antigen, a
  secondary immune response occurs.
• During a secondary immune response, the immune
  response is faster and more powerful.
• Most of the time, the secondary immune response
  protects the body from re-infection by a pathogen.

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Immune System Specific Defenses
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Immune System Specific Defenses

• Immunity and Vaccination
• Immunity is the ability to resist an infectious
  disease.
• Immunity can come about in two ways surviving an
  initial infection or through vaccination.
• Vaccination is the introduction of antigens into
  the body to cause immunity.

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Immune System Specific Defenses

• Immunity and Vaccination
• Vaccines
• Vaccination usually involves an injection of a
  vaccine.
• A vaccine is a solution that contains a dead or
  weakened pathogen or material from a pathogen
  that still contains antigens.
• The immune system will produce a primary immune
  response to the antigens. Memory cells can then
  provide a quick secondary immune response if the
  antigen ever enters the body again.

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Immune System Specific Defenses

• Problems of the Immune System
• Sometimes the immune system can react to harmless
  antigens. Three examples of this are allergies,
  asthma, and autoimmune diseases.
• Allergies
• An allergy is a physical response to an antigen,
  which can be a common substance that produces
  little or no response in the general population.

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Immune System Specific Defenses

• Problems of the Immune System
• Asthma
• Allergies can trigger asthma. Asthma is a
  respiratory disorder that causes the bronchioles
  to narrow due to an overreaction to substances in
  the air.
• During an asthma attack, the lining of the
  bronchioles and other respiratory tissues may
  also swell and become inflamed.

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Immune System Specific Defenses

• Problems of the Immune System
• Autoimmune Diseases
• An autoimmune disease occurs when the immune
  system attacks an organisms own cells.
• Autoimmune diseases can affect organs and tissues
  in various areas of the body.

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Immune System Specific Defenses

• Problems of the Immune System
• Acquired Immunodeficiency Syndrome
• AIDS is a disease caused by HIV (human
  immunodeficiency virus).
• Infection by HIV causes the immune system to lose
  its ability to fight off pathogens and cancers.
• HIV infection usually progresses to AIDS in three
  phases.

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Immune System Specific Defenses

• Problems of the Immune System
• Transmission of HIV
• HIV is transmitted by the transfer of body fluids
  containing HIV or HIV-infected cells.
• This most commonly occurs by sexual contact with
  an infected person or by use of syringes and
  hypodermic needles that have been contaminated
  with blood containing HIV.
• HIV cannot be transmitted through casual contact.

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Immune System Specific Defenses

• Problems of the Immune System
• Vaccines and Treatments for HIV
• Effective treatments and vaccines for HIV are
  difficult to create because HIV has a rapid
  mutation rate.
• Treatment is also difficult because HIV quickly
  becomes resistant to antiviral drugs.
• Most HIV treatments are expensive and require a
  complicated multidrug therapy.

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Reproductive System
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Reproductive System

• Male Reproductive System

• Male Reproductive Structures
• The male reproductive system contains two testes.
  
• The testes are the gamete-producing organs of the
  male reproductive system.

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Reproductive System

• Male Reproductive System

• Male Reproductive Structures
• Each testis is made up of the epididymis and the
  seminiferous tubules.
• The epididymis is a long, coiled tubule that is
  closely attached to each testis.
• The seminiferous tubules are tightly coiled
  tubules where sperm form through meiosis.

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Reproductive System

• Male Reproductive System

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Reproductive System

• Male Reproductive System
• Path of Sperm Through the Male Body
• From the epididymis, sperm move into the vas
  deferens.
• The vas deferens is a duct that extends from the
  epididymis to the urethra. This duct is made of
  smooth muscle and helps sperm exit the body.
• From the vas deferens, sperm move to the
  urethra.

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Reproductive System

• Male Reproductive System
• Path of Sperm Through the Male Body
• Once in the urethra, the sperm will mix with
  other fluids produced by the seminal vesicles,
  the prostate gland, and the bulbourethral glands.
  
• The seminal vesicles lie between the bladder and
  the rectum and produce a fluid that sperm use for
  energy.
• The prostate gland is located just below the
  bladder and produces a fluid that neutralizes the
  acids in the female reproductive system.
• The bulbourethral glands produce a fluid that
  neutralizes any acidic urine left in the urethra.

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Reproductive System

• Male Reproductive System
• Delivery of Sperm
• Fluids that are excreted from glands within the
  penis are mixed with the sperm to produce semen.
• After passing through the urethra, the semen will
  exit the body through the penis.
• The penis is the organ that deposits sperm in the
  female reproductive system.
• Ejaculation is the process in which semen is
  forcefully expelled from the penis by
  contractions of the smooth muscles that line the
  urethra.

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Reproductive System

• Female Reproductive System
• Female Reproductive Structures
• The female reproductive system contains two
  ovaries, two fallopian tubes, and a uterus.

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Reproductive System

• Female Reproductive System
• Female Reproductive Structures
• The ovaries are the gamete-producing organs of
  the female reproductive system.
• The fallopian tubes, also called the uterine
  tubes, are made of smooth muscle and join the
  ovary to the uterus.
• The uterus is a hollow, muscular organ about the
  size of a small fist and is the place where the
  fertilized egg will develop.

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Reproductive System

• Female Reproductive System
• Female Reproductive Structures (cont)
• The lower entrance of the uterus is the cervix,
  which leads to the female reproductive opening
  called the vagina.
• The vagina is a muscular tube that leads to the
  outside of the body. The vagina receives sperm
  from the penis, and it is also the channel
  through which a baby passes during childbirth.
• The vagina is protected by the vulva.
• The vulva is made up of the labia, folds of skin,
  and mucous membranes that cover and protect the
  opening to the female reproductive system.

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Reproductive System

• Female Reproductive System

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Human Development
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Human Development

• Gestation
• Fertilization
• If sperm are ejaculated into a female within 48
  to 72 hours of ovulation, the chances of those
  sperm finding and fertilizing and egg are likely.
• Once any sperm encounters an egg, it will try to
  penetrate its outer layers, but usually only one
  sperm is successful in fertilizing the egg.

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Human Development

• Gestation
• Fertilization
• When fertilization occurs, the egg and sperm fuse
  to form a zygote.
• A zygote is the diploid cell that results when
  the egg and sperm fuse together.
• The period of development from fertilization of
  the egg through the next nine months is known as
  gestation.

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Human Development

• Gestation
• Fertilization (cont)
• Cleavage and Implantation
• Once the egg is fertilized, the zygote will begin
  a series of mitotic divisions known as cleavage.
• During cleavage, the resulting cells remain the
  same size and produce a ball of cells called a
  morula.
• Once the morula divides further and releases a
  certain fluid, it is called a blastocyst.

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Human Development

• Gestation
• Fertilization (cont)
• Cleavage and Implantation
• The morula has become a blastocyst by the time it
  reaches the uterus.
• Once at the uterus, the blastocyst releases an
  enzyme that allows it to burrow into the
  thickened walls of the uterine lining. This
  process is called implantation.

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Human Development

• Gestation
• Pregnancy
• The nine-month period of growth and development
  that a blastocyst undergoes is called gestation
  or pregnancy.
• Pregnancy is divided into three equal periods
  called trimesters, and each trimester is signaled
  by specific events.

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Human Development

• Gestation
• Pregnancy (cont)
• First Trimester
• During the first eight weeks of pregnancy, the
  developing human is called an embryo.
• The placenta forms this is the structure
  through which the mother nourishes the embryo

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Human development

• Gestation
• Pregnancy (cont)
• First Trimester
• The placenta connects the mother to the embryo by
  way of the umbilical cord. The umbilical cord
  allows substances to exchange between mother and
  embryo by way of diffusion.
• From eight weeks until birth, the developing
  child is called a fetus.
• At the end of the first trimester, all of the
  organs of the fetus have begun to form.

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Human Development

• Gestation
• Pregnancy (cont)
• Second Trimester
• During the second trimester, the heartbeat of the
  fetus can be heard, its skeleton begins to form,
  and it begins to develop body fat.
• The baby has a layer of soft hair called lanugo
  growing over its skin.
• The baby begins to move, sleep, and wake.

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Human Development

• Gestation
• Pregnancy (cont)
• Third Trimester
• During the third trimester, the baby undergoes
  changes that will enable it to live outside the
  mother.
• It also develops fat deposits under its skin to
  insulate its body.
• These fat deposits also make the fetus look more
  rounded and less wrinkled.

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Human Development

• Gestation - Birth
• In reaction to hormones produced by both the
  fetus and the mother, childbirth is initiated.
• During childbirth, the smooth muscles of the
  uterus begin to contract and the muscles in the
  vagina and cervix relax and enlarge, which allow
  the fetus to pass through.

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Human Development

• Gestation
• Birth (cont)
• The process of muscle contractions and other
  related events that lead up to childbirth are
  called labor.
• After the fetus has been pushed through the
  vagina, contractions of the uterus help the
  mother expel the placenta, amnion, and uterine
  lining. This group of membranes is called the
  afterbirth.