Download Body Defenses and Excretion

Warm Up # 48 (copy all)
1. When you rub your hands together, they heat up due to ____.
A. inertia
B. friction
C. gravity
D. acceleration
2. If an object is moving at a constant speed and a force pushes it
in the same direction, the object will ___________
A. stop B. slow down C. accelerate D. stay the same speed
3. What does “homeostasis” mean? Give an example of
homeostasis in the human body.
Body Defenses and
Excretion
Statement of Inquiry—Health and wellbeing form a balanced system so that deliberate
lifestyle choices can lead to positive consequences.
Many systems help defend our bodies from harmful
materials:
Integumentary system (skin, nails, hair)--physical
barrier to prevent pathogens (germs) from entering
body
Respiratory system--coughing, sneezing remove
foreign particles, cilia and mucus trap other
particles
Digestive system--saliva, mucus, enzymes, and
strong stomach acids destroy pathogens
Immune system fights any pathogens
that get past these systems.
white blood cells fight infection and help
heal injury
antibodies--produced by white blood cells
fight specific pathogens
lymphatic system--similar to circulatory
system, but has no pump (no heart) filters
out pathogens, carries lymph
lymph--fluid left in body tissues by
circulatory system
Non specific response
swelling, redness, heat--first defense
against injury and infection
histamines--raises skin temperature,
allows white blood cells to arrive
quickly and fight pathogens
Specific Response
T cells and B cells fight specific antigens
(pathogens) by producing antibodies that
recognize the antigens
Some B cells remain in the body to fight
pathogens that enter the body later.
Immunity comes in two forms
passive--immunity babies receive
from their moms at birth
active--made by body in response to
pathogens or received from
vaccinations
Excretion—How does the human body
eliminate materials it does not need?
Excretory system (parts we have already
studied)
1. Respiratory removes CO2 and water
2. Digestive system removes solid waste
Two other systems that remove waste
1. Urinary system removes liquid
wastes from the circulatory system
2. Skin (integumentary system)
releases wastes through sweat glands
Urinary system consists of:
1. Kidneys--filter wastes and removes
excess water from the blood
2. Bladder--holds liquid wastes
3. Ureters and urethra--Ureters
connect the kidneys to the bladder.
Urethra carry excess liquid wastes out
of the body. The liquid waste is called
urine.
Kidneys also function to regulate water
balance in the body (homeostasis)
How do these body systems defend us
against foreign matter?
Body System Defenses
Integumentary System skin as barrier
Respiratory System mucus, cilia, coughing, sneezing
Digestive System saliva, mucus, enzymes, acids
Circulatory System white blood cells, antibodies