Download Lesson 5 Animal Systems

5th Grade Ch. 1 Lesson 5: Animal Systems
































What are the skeletal and muscular systems? (S.S. and M.S.)
S.S.: Made up of bones, tendons, and ligaments
Bones have 2 functions:
o Protection for some soft organs (rib cage protects heart and lungs)
o Provide a solid framework for the body
Bones are living tissues and are light and strong
Bones give the body structure and allow movement
Bones move freely but not on their own
M.S.: provides power to produce bone movement
Skeletal muscles are attached to bones by tough, rubbery tendons.
Muscles shortening (or contracting) make bones move
Muscles allowing movement work in pairs or opposing groups (one muscle pulls
up and another pulls down)
Electrical nerve signal is sent from the brain to the muscle making the muscle
contract
Contracted muscle pulls on the tendon moving the bone up.
Muscles can only pull-NEVER PUSH!  muscles contract and relax
Muscle pulling up contracts causing the muscle pulling down to relax
What are the digestive and excretory systems? (D.S. and E.S.)
D.S.: long tube in which food is broken down into nutrients that an organism can
use.
Teeth grind food and saliva begins the chemical breakdown of it.
Chewed up food travels through a muscular tube called the esophagus (smooth
muscles of the esophagus contract and expand to squeeze food down to the
stomach – like squeezing a tube of toothpaste)
Stomach holds partially digested food which is then broken down by strong acids
Contents are emptied into the coiled Small Intestine (S.I.)
The Liver and Pancreas produce digestive juices that combine with food in the
S.I. and break down sugars, proteins, and fats into nutrients which are then
absorbed in the S.I.
Tiny folds in the S.I. touch tiny blood vessels that deliver nutrients to the blood
There is always some undigested food during digestion.
Large Intestine (L.I.) reabsorbs H2O from undigested food
Remaining solid waste is processed in L.I. and leaves through 2nd opening in D.S.
E.S.: removes waste products from the body
Excess H2O, salt, and other waste is removed through the skin as sweat
Cells also create waste including CO2 and Nitrogen-containing wastes
CO2 is removed by the lungs
Nitrogen wastes are sent to the blood and travel through the Liver to the Kidneys
Liver breaks down toxin in the blood
Toxin: poisonous substance































Kidneys filter wastes from the blood
Nephrons: millions of tiny filters in the Kidneys that separate waste from useful
materials in the blood
Nephrons send any useful substance back into the blood and collect the wastes
Kidneys make urine from excessH2O and waste from nephrons
Urine flows from Kidney to the Bladder
When the Bladder is full, the urethra carries urine from the bladder to the outside
of the body
What are the respiratory and circulatory systems? (R.S. and C.S.)
Animal cells need 2 things to produce energy:
o Oxygen
o Food
R.S. and C.S. work together to provide oxygen and food to cells
R.S.: made up of lungs and the passageways that lead to them (fish use gills for
gas exchange)
C.S.: made up of heart and blood vessels
Air enters the body through nose and mouth via inhalation and then travels
through a series of tubes
Tubes inside the lungs branch into smaller tubes called bronchi which have
branches like a tree
Branches empty into very thin-walled air sacs called alveoli which let gasses like
O and CO2 pass through
Circulation begins as Oxygen-poor blood and is pumped into the heart and lungs
In the lungs, blood carrying CO2 picks up O from the air in the alveoli and
releases CO2 at the same time
CO2 is a waste product of cellular respiration
CO2 leaves the body during exhalation
Oxygen-rich blood flows back to the heart which pumps blood around the body
Blood picks up nutrients when it reaches the S.I.
Nutrient and O-rich blood is delivered to the body’s cells
Blood travels through blood vessels
Blood reaches tiny vessels called capillaries
Dissolved nutrients and O can pass through their thin walls and enter the cells
Cells past waste materials back through the capillaries and into the blood
O-poor blood is pumped back to the heart and the process continues
What are the nervous and endocrine systems? (N.S. and En.S)
Vertebrate N.S. includes the brain, nerve cord, nerves, and sense organs
Works with En.S. which has hormone producing glands
Hormones: Chemicals released into blood stream that change body activity
When a rabbit sees a fox:
o Light reflecting of the fox hits the rabbit’s eyes
o Nerve-cells in the eyes send an electrical nerve message to the brain

o Brain sends a message back which travels through nerves via the spinal
cord
o At the cord the nerves sends the message to the rabbit’s legs telling them
to run
Adrenaline: a hormone that increases the heart rate and sends extra blood to the
muscles making them ready for anything.