Transcript Human Body Systems

Unit 6
Human Body Systems
Regents Living Environment
Levels of Organization
The levels of organization in a multicellular
organism start with the individual cell.
A group of similar cells that do the same
function (job) are tissues.
Similar tissues form organs that do a complex
function for example the kidneys filter urea from
the blood.
Organs work together in organ systems. The
circulatory and respiratory systems work
together to perform gas exchange (oxygen and
carbon dioxide) in the body.
Regents diagram of the Levels of
Organization
Human Organ Systems
Human Body Systems
Integumentary System – skin, hair, nails,
sweat and oil glands.
Function – barrier against infection & injury;
helps regulate body temperature; protects
against UV radiation from the sun.
Nervous System – brain, spinal cord, peripheral
nerves.
Function – recognizes & coordinates the body’s
response to changes in its internal & external
environments. (i.e.touching a hot stove)
Human Organ Systems
Skeletal System – bones, cartilage, ligaments &
tendons
Function – supports the body; protects internal organs;
allows movement; stores mineral reserves; site of
blood formation.
Human Organ Systems
Endocrine System – hypothalamus, pituitary, thyroid,
parathyroid, adrenals, pancreas, ovaries (females),
testes (males).
Function – controls growth,
development, metabolism &
maintains homeostasis.
 Hormones - chemical released
by cell in one part of the body,
that sends out messages that
affect cells in other parts
of the organism.
HORMONES
Hypothalamus
Part of the brain and connected to the
pituitary gland.
Thyroid and Parathyroid
Glands located in the neck.
Thymus
Located near the top of the heart.
Adrenal
Found at the top of the kidneys.
Pancreas
Located adjacent to the stomach.
Ovaries
Located in the pelvis, but only in
females.
Testes
Male organs located in the scrotum.
Hormones Insulin and Glucagon
These two hormones
help us to maintain a
stable glucose level
(Homeostasis)
Hormones
Epinephrine (also known as adrenaline) is a
hormone has many functions in the body,
regulating heart rate, blood vessel
Testosterone- plays a key role in the
development of male reproductive tissues such
as the testis and prostate as well as promoting
secondary sexual characteristics such as
increased muscle, bone mass, and the growth of
body hair
Hormones
Estrogen-promotes the development of
female secondary sexual characteristics,
such as breasts, and are also involved in
the thickening of the endometrium and
other aspects of regulating the menstrual
cycle.
Hormones Insulin and Glucagon
These two hormones
help us to maintain a
stable glucose level
(Homeostasis)
Circulatory System – heart, blood vessels
(veins, arteries, & capillaries), blood.
Function – brings oxygen,
nutrients & hormones to cells;
fights infection; remove cell
wastes; regulate body
temperature
Human Immune System
Lymphatic/Immune System – White blood cells,
thymus, spleen, lymph nodes, lymph vessels.
Function – helps protect the body from disease;
collects fluid lost from blood vessels & returns the
fluid to the circulatory system.
Autoimmune diseases arise from overactive immune
response of the body against substances and tissues
normally present in the body. In other words, the
body actually attacks its own cells. The immune
system mistakes some part of the body as a
pathogen and attacks it.
Autoimmune Diseases
Crohns Disease: Crohns disease is a disorder
of the intestine.
Diabetes Type 1: the body's immune system,
attacks the insulin producing cells in the
pancreas
Multiple sclerosis (MS): the body's immune
system attacks its own central nervous system.
Rheumatoid Arthritis: leads to the destruction
of all the cartilages at the joints
HIV stands for Human Immunodeficiency
Virus.
A person is said to be HIV positive if that person
is infected with HIV virus.
Testing positive for HIV virus does not become
AIDS until immune system is compromised
which usually takes ten years.
A person who has been diagnosed with AIDS is
always at risk of getting life-threatening
diseases, called opportunistic infections
32.9 million people were living with HIV/AIDS
worldwide as of end of 2007
Respiratory System – Nose, trachea, bronchi,
bronchioles, & lungs.
Function – provides oxygen needed for cellular
respiration & removes carbon dioxide from the
body.
Human Organ Systems
Digestive System – mouth, esophagus, stomach,
small & large intestine, rectum.
Function – Breaks down food into simpler molecules
(starch is too large to move through membranes)
using enzymes that can be used by the body cells;
absorbs food; eliminates wastes.
Waste (Feces or solid waste) is not excretion of
metabolic waste but simply the end products of
digestion
Digestive System
Remember
that the
appendix is
a vestigial
organ
Excretory System – skin, lungs, kidneys,
ureter, bladder, urethra.
Function – eliminates waste products of
metabolism and helps maintain homeostasis.
People with
Kidney disease
may be treated
with kidney
dialysis
Human Organ System
Reproductive System –The reproductive
system or genital system is a system of
organs within an organism which work
together for the purpose of reproduction
Function – produces reproductive cells
(gametes). Male gamete is sperm, Female
gamete is ovum/egg.
.
Males
Males – testes, epididymis, vas deferens,
urethra, penis.
Sperm are produced
by the cell division
process of Meiosis
Females
Females – ovaries, fallopian tubes, uterus,
vagina.
Eggs are produced
by the cell division
process of Meiosis
Sexual Development
For the first six weeks of life male & female
embryos are identical in appearance. (Pigs,
birds and reptiles also look very similar)
During the seventh week the primary
reproductive organs testes in males, ovaries in
females begin to develop.
The testes begin to produce testosterone and
the male reproductive organs are formed.
If it’s a female, the ovaries produce estrogen,
which produces the female reproductive organs.
Puberty
The reproductive organs are not capable to produce
active gametes (sex cells) prior to puberty. (The
genes involved have not “turned on “ yet)
Puberty is a period of rapid growth and sexual maturity
where the reproductive organs become fully
functional.
Puberty usually starts between the ages of 9 & 15
years.
The hypothalamus signals the pituitary gland to
release follicle-stimulating hormone (FSH) and
luteinizing hormone (LH)
The Male Reproductive System
The main function of the male reproductive system is
to produce & deliver the male gametes (sperm).
The primary male reproductive organs, the testes
develop in the abdomen. Before birth the testes
descend into the scrotum.
The testes remain in the scrotum, outside the body,
where the temperature is one to three degrees lower
than normal body temperature. The lower temperature
is important for proper sperm (gamete) development.
Sperm Development
Sperm cells are haploid which means they have
23 chromosomes.
The sperm cells have many mitochondrion.
Why?
Sperm Development
Sperm produced in the testes are moved into the
epididymis, where sperm mature & are stored.
The sperm move into the vas deferens. The vas
deferens merges with the urethra the tube that leads
to the outside of the body through the penis.
The glands lining the reproductive tract including the
seminal vesicles & prostate gland produce a nutrient
rich seminal fluid. The combination of sperm &
seminal fluid is known as semen.
50 – 130 MILLION sperm are present in 1 ml of
semen.
Male Reproductive System
Female Reproductive System
The ovaries are the primary reproductive organ for
females. This is where the eggs/ovum are stored.
The main function of the female reproductive system
is to produce ova (eggs). The female reproduce
system also prepares the females body to nourish a
developing embryo.
The ovaries usually produce only one mature ovum
(egg) each month.
Females are born with thousands of immature eggs
(follicles) only about 400 eggs will actually mature &
be released
Egg Release
Approximately every 28 days, when a follicle has
matured, the egg is released during ovulation.
The egg is released from the ovary and floats through
one of the two fallopian tubes. As it moves through the
fallopian tube the egg may be fertilized.
The egg moves from the fallopian tube into the uterus.
The lining of the uterus is ready for a fertilized egg.
If an unfertilized egg comes into the uterus, the uterine
lining will shed resulting in menstruation.
Female Reproductive System
Menstrual Cycle
The menstrual cycle is controlled by hormones made
by the hypothalamus, pituitary gland & ovaries. This
cycle is controlled by a feedback system.
The menstrual cycle begins at puberty and continues
until the mid-forties. The production of estrogen drops
and ovulation & menstruation stop. The permanent
stopping of the menstrual cycle is called menopause.
The average age of menopause for women is 51.
Menopause can happen earlier or later depending on
the individual female.
Sexually Transmitted Diseases (STDs)
Sexually transmitted diseases are spread from one
person to another during sexual contact.
Chlamydia is an STD caused by bacteria. Females
between the ages of 15 – 18 have the highest rate of
Chlamydia infection. This infection can cause infertility
(inability to have children).
Other STDs include syphilis, gonorrhea, Viral STDs
hepatitis B, genital herpes & warts, & AIDs.
STDs can be avoided by abstaining from sex or using
condoms to help protect you from STDs.
Fertilization
Fertilization of an egg usually happens in the
fallopian tube. Hundreds of millions of sperm swim
through the cervix, uterus and into the fallopian tubes,
if an egg is present it may be fertilized.
The egg is surrounded by a protective layer that has
binding sites where sperm can attach. Fertilization of
the egg restores the chromosome number to 46
(23 egg plus 23 sperm= 46)
Once the single sperm enters the egg, the egg
releases a barrier to the outside of the cell that
prevents any other sperm from entering. The fertilized
egg is called a Zygote.
Fertilization
While the zygote is still in the fallopian tube it begins to
divide through Mitosis (2N cells).
About six days after fertilization the fertilized cell
implants into the uterus.
After implantation, the cell starts to specialize into
different tissues in the body. This process of cell
differentiation creates the different tissues types and
systems of the body.
Membrane Development
As the embryo develops, membranes form to protect
and nourish it.
Two of the membranes
are the amnion and the chorion.
The amnion becomes the fluid-filled
amniotic sac that cushions & protects
the developing embryo in the uterus.
The chorion has small finger-like projections called
chorionic villi form on the outer layer of the chorion
and plant themselves in the uterine lining.
Placenta
The chorionic villi & uterine lining form the placenta.
The placenta is the connection between mother and
baby.
The developing embryo needs nutrients & oxygen. It
also needs to eliminate carbon dioxide & metabolic
wastes.
Nutrients & oxygen in the mother’s blood diffuse into
the embryo’s blood in the chorionic villi. Waste diffuse
from the embryo to the mother.
The mother & baby’s blood flow past each other but
DON’T MIX. They are SEPARATED by the placenta.
Placenta after Birth
Fetal Development
The first weeks of pregnancy are very important
because many external factors can disrupt or harm the
embryo’s growth & development.
The placenta helps to protect the baby but some
substances can cross the placenta and affect the
baby. This includes German measles, drugs like
alcohol, cocaine, heroin, and medications.
Reproduction In other
Organisms
Reproduction (or procreation) is the
biological process by which new "offspring"
are produced from the Parent (s).
Methods of reproduction are broadly grouped
into two main types: sexual and asexual
Some organisms can reproduce both sexually
and asexually (a lot plant can do this)
Asexual Reproduction
Asexual reproduction-only one parent
required to produce offspring
-exact copy of parent (clone)
-ALL cell divisions are MITOSIS
Examples: budding, fisson, strawberry
runners and root cuttings
Sexual Reproduction
Sexual Reproduction-requires two parent
organisms with each contributing half of the
offspring's genetic makeup
-Production of gametes uses Meiosis
All other cell divisions in Sexual Reproduction
are MITOSIS
-Lots of genetic variation in offspring
Internal Fertilization
Internal Fertilization-egg is fertilized inside
the body of the female.
Internal Fertilization is necessary for
animals which live on land (terrestrial
animals) and is retained by aquatic
animals descended form terrestrial
ancestors eg whales and dolphins.
External Fertilization
External Fertilization-egg is fertilized
outside the body of the female.
External Fertilization
After external fertilization the eggs are
potentially exposed to predators and so
must either be produced in very large
numbers or protected by the parents or
both.