Search for notes by fellow students, in your own course and all over the country.
Browse our notes for titles which look like what you need, you can preview any of the notes via a sample of the contents. After you're happy these are the notes you're after simply pop them into your shopping cart.
Document Preview
Extracts from the notes are below, to see the PDF you'll receive please use the links above
Chapter 3 – Skeletal and Muscular System
Subject - Science
Class V
Skeletal system and its functions
Skeletal system is the framework of the body, consisting of bones and other
connective tissues, which protects and supports the body tissues and internal
organs
...
The skeletal system is the body system
composed of bones and cartilage and performs the following critical functions for
the human body supports the body facilitates movement
...
Each bone is
a complex living organ that is made up of many cells, protein fibers, and
minerals
...
The functions of the skeletal system are:
1
...
2
...
(ii) The rib cage protects the heart and the lungs
...
3
...
4
...
They are filled with a jelly-like
substance called bone marrow
...
Parts of the skeleton
The different parts of the skeleton system are:1
...
The skull or known as the cranium in the medical world is a bone structure of the
head
...
The adult skull has a total of
22 individual bones
...
The skull
performs vital functions
...
Rib cage: The rib cage protects the heart and lungs
...
It has 24 ribs
in 12 pairs
...
It
encloses and protects the heart and lungs
...
3
...
The spine (or
backbone) runs from the base of the skull to the pelvis
...
There are three natural
curves in the spine that give it an "S" shape when viewed from the side
...
The spine is made up of a series of bones that are stacked like blocks on top of
each other with cushions called discs in between to help absorb shock/load
...
Limbs: (Arms and legs) help us in doing many activities and in moving from
one place to another
...
Arms and legs are connected to torso or trunk
...
Structure of a bone
Bones have hard outer layer called cortical (compact) bone, which is strong,
dense and tough and spongy inner layer called trabecular (cancellous) bone,
which is lighter compared to compact bone
...
That is how they
grow as we get older
...
Bones are strong but light in weight as they are hollow from inside
...
Bone marrow is the flexible tissue in the interior
of bones
...
Usually child
is born with 300 soft bones
...
The smallest bone is stapes which is present
inside our ear
...
They produce red blood cells
...
They act as storage for calcium and phosphorus, essential minerals for
various cellular activities throughout the body
...
Hinge joints are formed between two or more bones
where the bones can only move along one axis to flex or extend
...
Ball and socket joints: This is the type of joint in which ball shape surface of
one bone fitted into the hollow space of another bone also called socket
...
Pivot Joint: This type of joint allows movements in many planes, viz
...
Pivotal joints allow for rotation, twisting, extension, and flexibility
...
Saddle joint: It is also known as sellar joints
...
Muscular system and its functions
The main function of the muscular system is movement
...
Related to the function of movement is the muscular system's
second function: the maintenance of posture and body position
...
Mobility
The muscular system’s main function is to allow movement
...
Gross movement refers to
large, coordinated motions and includes:
walking
running
swimming
Fine movement involves smaller movements, such as:
writing
speaking
facial expressions
The smaller skeletal muscles are usually responsible for this type of action
...
However, some
movements are reflexive, such as withdrawing a hand from a source of heat
...
Stability
Muscle tendons stretch over joints and contribute to joint stability
...
The
core muscles are those in the abdomen, back, and pelvis, and they also stabilize
the body and assist in tasks, such as lifting weights
...
Posture
Skeletal muscles help keep the body in the correct position when someone is
sitting or standing
...
Good posture relies on strong,
flexible muscles
...
Long-term, bad posture leads to joint and muscle pain
in the shoulders, back, neck, and elsewhere
...
Circulation
The heart is a muscle that pumps blood throughout the body
...
Smooth muscle in the arteries and veins plays a
further role in the circulation of blood around the body
...
They
expand to increase blood flow during times of intense exercise when the body
requires more oxygen
...
Respiration
Breathing involves the use of the diaphragm muscle
...
When the diaphragm contracts, it pushes
downward, causing the chest cavity to get bigger
...
When the diaphragm muscle relaxes, it pushes air out of the lungs
...
6
...
The GI tract
stretches from the mouth to the anus
...
Muscles in the walls of the hollow
organs contract and relax to cause this movement, which pushes food through the
esophagus into the stomach
...
The digested food moves from the stomach to the intestines by
peristalsis
...
7
...
Urinary problems, such as poor bladder control or retention of urine, are caused
by damage to the nerves that carry signals to the muscles
...
Childbirth
Smooth muscles in the uterus expand and contract during childbirth
...
Also, the pelvic floor muscles help
to guide the baby’s head down the birth canal
...
Vision
Six skeletal muscles around the eye control its movements
...
10
...
The bones of the spine and the ribs provide further protection
...
11
...
Almost 85 percent of the heat a person generates in their body comes
from contracting muscles
...
Shivering is one example of
this mechanism
...
Body temperature can be brought back within normal range through the
relaxation of smooth muscle in the blood vessels
...
Different types of muscles
QUESTION & ANSWER
Q1
...
A1
...
Q2
...
The functions of the skeletal system are:
1
...
2
...
(ii) The rib cage protects the heart and the lungs
...
3
...
4
...
They are filled with a jelly-like
substance called bone marrow
...
Q3
...
A joint is the connection made between bones in the body which link the
skeletal system into a functional whole
...
Joints are classified both structurally
and functionally
...
Differentiate between movable and immovable joints
...
Q5
...
Generally, two skeletal muscles are joined to one bone, so that when one
muscle contracts in one direction for enabling the bone to move in that specific
direction; the other muscle becomes relaxed to facilitate the movement of the
bone
...
Why is posture important?
A6
...
Stiff, weak, or tight muscles
contribute to poor posture and misalignment of the body
...