this document lists & describes the function of human tissues and organs

1. Human biology -- tissues & organs
Features of muscle which are in common ---
• They are specialized for contraction
• They all have contractile fibre which bound together by connective tissue which connects
muscle with bones or skin
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• The energy need for contraction by muscles mainly comes from respiration
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• Between the muscle fibres an extensive network of blood capillaries runs
• Contraction of muscle fibre is caused by a complex re arrangement of its protein molecules
Involuntary muscle
• Found in the walls of the gut, blood vessels and bladder
• It cannot be contracted at will
• Controlled by unconscious mechanisms
• Its fibres are single cells which are elongated & pointed at each end
• They control processes like peristalsis
Cardiac muscle
• Found only in the heart
• It consists of single cells which are branched & joined together making a network of fibres
• Its fibre contract rhythmically with moderate speed throughout life, pumping blood around the
body
Voluntary muscle
• Attached to the skeleton
• Can be contracted at will
• They consist of many cells & their structure is very complicated
• They can contract quickly & powerfully & causes movement of the body
Structure of involuntary muscle
• It has blood vessels & nerves
• Have nucleus
• It has connective tissue
• Have muscle fibres [pointed at both ends]
• Have circular muscle & longitudinal muscle in small piece of gullet
Structure of cardiac muscle
• It is found in the heart
• Have one cardiac muscle cell
• Thick cardiac muscle in the ventricle wall
• Branched cells joints to form a network of contractile fibres
Structure of voluntary muscle
• Have nerve fibre
• Have blood vessels
• One voluntary muscle fibre

2. Human biology -- tissues & organs
• Have nerve endings on muscle fibres
Function of the cilia
• Cilia flick back and forth causing the movement of surrounding fluids
• Cilia carries dust and bacteria by away and protects the lungs
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Functions of the epithelial tissue
• These tissues consists of sheets of cells which cover the external and internal surface of the
body, and line the inside of the gland
• This tissue covers the heart, lungs and other organs and lines the spaces in which the organs lie,
reducing friction between surfaces which rub together
• This tissue consist of glandular epithelium, which are specialized to produce useful substances
like enzymes, mucus and hormones
Main function of the nervous tissue ---
• Conduct messages by a cell called nerve impulses
• This message are passed through neurons to response
• Nerve impulses can be described as a travelling wave of electrical and chemical changes along a neurone
as a result of stimulus
Common characteristics of all connective tissues
• All consist of cells embedded in an intracellular substance called matrix
• From matrix cells produce
• They connect tissues & organs
• Protect & support the organs and allowing them to move against one another
Aerolar tissues are found in the spaces between organs
Functions:
• Consist of fibres &cells enclosed in a white sticky matrix which is produced by mast cells and these
also produce heparin, a chemical which stop blood from clotting inside the blood vessels
• For this macrophage cells engulf & digest bacteria which enter wounds & can move through the
matrix to infected areas
Differences between:
Cartilage Bone
It is a strong material but it is not brittle It is a hard substance and it is brittle
It is flexible tissue It is a connective tissue
Have perichondrium Have periosteum
Not so Have vein & artery
Produce wind pipe Produce blood cells
Cartilage is found when the baby is started to its Bone is found after the birth of a baby
formation
Main functions of:
• Vertebral column ---
• Attached to all vertebrae

3. Human biology -- tissues & organs
• Movement of the vertebrae
• Joints with ribcage, skull &hip
Ribcage ---
• Protects the heart & lungs
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• Maintains the shape of the body
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• Supports diaphragm muscle which is concerned with breathing
Skull ---
• Protects the brain
• Protects inner & middle ears & nasal organs
• Sockets in there protects the eyes
Femur ---
• It is a thigh bone which consist of a long hollow shaft
• And also consists of two rounded ends or heads called epiphysis
• It is long bone
• It is called as appendicular skeleton
• It allows the whole body to freely move at will
Function of each part of the bone:
• Epiphysis – it is sticky for which it rub against another bone at a joint
• Diaphysis – it is hard for which bone cannot break easily
• Periosteum – it protects the bone
• Hard compact bone – gives the shaft its strength
• Bone marrow – fatty tissue in which blood cells are manufactured
• Spongy bone – it consists sticky material for which epiphysis can do its work
Ossification is the process by which cartilage is transformed into bone during the growth of a baby
A brief summary of ossification is given below:
• Bone forming cells develop around the middle of a long bone’s shaft and form a thin cylinder of
bone which supports the remaining cartilage as it is replaced by bone
• Cartilage becomes saturated with calcium salts by a process called calcification. Cartilage cells
then swell up and die leaving rows of empty holes
• Bone forming cells from the surface and blood vessels grows into the bone. They open up the
rows of holes forming tunnels lengthwise along the bone. Bone forming cells lay down concentric
rings of bone along the blood vessels forming bone tissue
• A strip of cartilage remains between the shaft and the head of the bone because it helps to grow
the bone and development of a body

4. Human biology -- tissues & organs
Types of synovial joints and functions
• Ball and socket joint – allows movement in all directions
• Hinge joints – movement can occur only in one direction
• Sliding joints – movement between vertebrae
• Pivot joint – occurs when one bone twists against another
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• Neural canal --- each vertebrae has an opening called neural canal through which the spinal cord passes
In brief, the neural canal provides space for spinal cord to occupy
Osteoblast --- cells which manufacture the bones
Chondroblast --- cells which manufacture cartilage
Functions of bones ---
• Giving the body shape
• Assisting in movement
• Producing blood component cells from the bone marrow
• And even storing minerals such as calcium & phosphorus
The skeleton consists of:
• Bones [206]
• Cartilages
• Joints – also called articulations, junction between skeletal elements
• Ligaments – connect bones
Three types of muscle ---
• Skeletal [voluntary]
• Cardiac [involuntary]
• Smooth [involuntary]
2 types of bone tissue exist ---
• Spongy
• Compact
5 Types of connective tissue –
Blood, loose, dense, cartilage, bone
Synovial joint ---- any joint where there is a space between bones
Muscular system – component: skeletal muscle [contraction allows for voluntary movement]
Functions of the muscular system ---
Movement &locomotion, mechanical work [lifting, pulling, pushing objects], communication [body
language & facial expression]
Tension on tendons by muscles cause movement of the bone
Skeletal muscle ---
• Composed of individual muscle fibres
• Contract when stimulated by motor neurone
• Attached to bone on each end by tendons