Skeleton System

 Part 2

Functions of the bones

* Support and shape

Bone provide a framework of the body.

It gives support and shape of the body.

It also gives attachment to muscles and tendons.

* Protection

The bones protect  inner soft and delicated organs , forming the boundaries of the cranial, thoracic, abdominal and pelvic cavities protecting the organs they contains by external shocks.

* Movement

It provide moment of the whole body and parts of the body by forming joints.

Bones of the body provide attachment to the muscles , these muscles provide motor power for providing movement of the body parts.

* Mineral storage

Bones serve as a reservoir for calcium and phosphate , essential minerals for various cellular activities.

* Blood cell production

The production of blood cell or hematopoiesis, occur in the  red marrow found within the cavity of the certain bone.

* Energy storage

Lipids such as fats , stored in adipose cell of the yellow bone marrow serve as energy reservoir.

General structure of long bone:--

Long bone

These have a diaphysis (shaft)and two epiphysis (extreme).

The diaphysis is composed of compact bone with the central medullary canal , containing fatty yellow bone marrow.

The epiphysis consists of an outer covering of compact bone with spongy (cancellous)bone inside containing red bone marrow.

Red bone marrow are responsible for production of blood cell or  hemopoiesis (RBC ,WBC, platelets).

The metaphysis is the part of bone between the epiphysis and the diaphysis.

It contain the connecting cartilage called epiphysial plates. It is the most actively growing area of long bone.

When  bone  oxicified the epiphysial plate (metaphysis) disappear at adulthood (18 - 20 years of age) as it convert into epiphysial line.

Long bone are covered by vascular membrane called periostium which has two layers.

The outer layer of fibrous rich in blood vessels and the inner layer contains osteoblast , which are involved in bones growth in thickness.

Maintenance and remodeling of bones and it is give attachments  to muscles and tendons and it protect bone from injury.

The periosteum covers the whole bone except for site of articulation ends.

Microscopic structure of bone

Bone are made up of cells and intracellular matrix.

The cellular component is 2% of bone mass

Matrix is made up of 40% of organic substance containing mainly of collagen fibres.

Collagen very strong and gives bone slightly flexibility.

60% of inorganic substance made up of  inorganic salts of calcium and phosphorus . This inorganic matrix gives bone great hardness.

Bones composition

Cellular Components

It consists of following cells........

1. Osteoblast

Osteoblast  is responsible for making new bone and repairing older bone.

It produce protein mixture "osteoid"  which is mineralized and becomes bone.

Osteoid is a type of protein mixture which is formed by collagens.

They are present in the dipper layers of periostium.

In the centres of ossification of immature bone.

At the site of fracture.

2. Osteocyte Cell

As bone develop osteoblast become  trapped within the newly formed bone.

They stop forming new bone and this stage are called osteocytes.

These are the mature bone cells that monitor and maintain bone tissues and are nourished by tissue fluid in the canaliculi,  it present in bone matrix.

3. Osteoclast

Osteoclast are multinucleated cell.

Osteoclast help in the reabsorption during remodelling of bones to maintain the optimum shape.

It is type of gold sale that breaks down bone tissue and releasing calcium and phosphate this process also help to regulate the level of blood calcium.

It present under periosteum and sight of old injured or unneeded bones.

                Matrix

Matrix is the extracellular component of bone which is made up of organic and inorganic components.

Organic component

This is  mostly made up of collagen fibres which are arranged in bundles . They have lamellar arrangement , which is in the form of a regular, parallel , lamilae.

Inorganic Components

The mineral components of bones gives it hardness and rigidity . It consists of calcium and phosphate they are closely packed and arranged along the collagen fibre.

Microscopic structure of compact bone

It is made up of many cube like structures called osteons . ( Habersion system)  

In between osteon a central canal is present .

The central canals contains blood vessels , nerve and lymphatic vessels are present.

 Central canal are connected neighbouring canal by perforated canals. 

If cut a series of osteon are seen  parallel series called lamellae.

 In lamellae present in small small pocket or cavities called  lacuna (containing osteocyte Cell).

Osteocyte cell maintain bone tissue.

Each lacuna are connected by canaliculus (canaliculi).

 Canaliculus are contain in interstitial fluid flow in canaliculus. This fluid provide nourishment to osteocyte cells.

Microscopic structure of spongy bone (cancellous bone)

Cancellous bone and less dense and present with large cavities in between plats of bones giving them a honeycomb appearance bone.

Cancellous bone is made up of  mashwork of bony plates or rods called "trabeculae" .

It does not contains osteons.

Each trabeculae is  made up of number of lamellae between which there are containing osteocytes.

Lacunae are interconnected by canaliculi.

The Trabeculae enclose wide spaces that are filled in by Red Bone Marrow.

They receive nutrition from blood vessels in bone marrow.

The trabecular are covered externally by vascular endosteum.

Endosteum is the lining membrane of the bone marrow cavity.

 

 Part 1

 Endocrine System

The endocrine system maintain the stability of internal environment. The endocrine system consists of glands . Glands are the group of epithelial cells. They produce specialised secretion.  Gland are two types:----

1. Exocrine glands

They discharge their secretion  on to the epithelial surface of an organ ,  either directly or through a duct and are called if the exocrine gland.

They vary in shape,size and complexity.

Endocrine gland

Endocrine gland are type of gland which secret hormone into the blood and lymph . Endocrine gland is a ductless  gland.

Hormones

It is a chemical substance , i.e. secreted into the body fluids by one cell or a group of cell. It regulate the body's activity. It is also called as chemical Messengers.

Pituitary Gland and Hypothalamus

* The pituitary gland and Hypothalamus work together.

* The pituitary gland also called hypophysis.

* Their secretion control the function of other gland.

* It is also called master endocrine gland.

* It about 1.2 to 1.5 cm in length it's weight is about 0.5gram.

* The gland has  a stem like stalk called the infundibulum, which connects it to the hypothalamus of the brain. 

* It secretes a different hormones.

* The pituitary look like one gland, but is consist of 2 glands. That are as follows .....

A) Anterior pituitary gland     7 hormones

B) Posterior pituitary gland     2 hormones

Anterior pituitary gland is also known as adenohypophysis.

Growth Hormones (gh)

It is also known as Somatotrophin hormones.

It is synthesis by anterior pituitary gland.

It helps in the growth of muscles and other tissues.

The hypothalamus secretes the growth hormone releasing inhibition hormone(GHRIH ).

2. Thyroid stimulating hormone (TSH)

This hormone synthesized by the anterior pituitary gland.

It is also called thyrotropin

It helped in the growth and development of target glands.

Thyroid stimulating hormone secrete 2 harmons..

Triiodothyronine ( T3 ) and thyroxin (T4) 

Skeleton System

 Part 1

Unit 2

        Skeleton System

Introduction

Bone :- It is a strong and durable type of connective tissue.

Skeletal system is composed of bone associated cartilages, ligaments, tendons and joints of human body.

Skeleton provide hard framework of human body for protection of smooth argan.

The study of bone and associated structure called osteology.

Two bone articulate together and forms joints.

Joints make the hard and rigid skeleton allow different types of movement at different location.

Human skeletal system composed of 206 bones is divided into two parts_____

1. Axial skeletal system ( 80 bone )

2. Appendicular skeletal system ( 126 bone )

Components of skeletal system

Human skeletal is composed of five main components bones , cartilages , tendon, ligaments and joints.

Bone :- Bone is a tough and rigid form of connective tissue . It is the weight wearing organ of human body and it is responsible for all  strength of human skeletal.

Cartilage :- It is also a form of connective tissue but it is not tough and rigid as bone

Tendons :- A fibrous band of connective tissue that is bonded to bone and connects muscle to bone.

Ligaments: Bands of strong connective tissue called payments hold bone together.

Joints :- A joint is where two or more bone in the body come together.

Composition of bone

Bone consists of ___

Water = 25%

Organic constituents mainly osteon and bone cell = 25%

Inorganic constituents mainly calcium and phosphate = 50%

Types of Bones____

Bone of The Skeleton are classified as_____

Long bone :- it consists of a shaft and two extremities.

Long bone are found in the limbs.

e.g. femur , tibia and fibula

Short Bone 

These bones have no shaft  but they contain a spongy substance covered by a shell  of compact bone.

 They are cubicle in shape. e.g :- carpels (wrist)

The smallest bone of the body is stapes .  It present in middle ears.

Flat bone

They are thin and flattened bones they contain two layer of compact bone with a sponge substance in between. 

e.g. Sternum, ribs and most of the skull bone.

Irregular Bone :- they don't have regular size, shape.

e.g. vertebral bones and bones of the faces.

Sesamoid :- Sesamoid bone are small bone with developed in tendon of muscles.

e.g. patela bone of knee bone 

Anatomy unit 1

 Part 4

                          CELL

Cell is the smallest functional unit of the body.

Cell are two types_______

Eukaryotic :- It contains nucleus.

Prokaryotic :- It do not contain nucleus.

Group of cell makes tissues; group of tissues make organs; group of organ make organ systems.

Structure and function of cell

Human body develop in a single unit called zygote, which forms by the fusion of female ovum and male sperm.

Ovum + sperm = zygote

Cell multiply and forms the fetus.

Cell is too small to be not seen with naked eyes.

Cell contain of plasma membrane, inside which their are numbers of organelles, floating in watery fluids are called cytosol or cytoplasm.

Organelles are small structure with highly specialised functions.

Cell contains

1. Plasma membrane

The cell membrane is protective sheath envelope the cell body. It separates the fluid outside the cell called extra cellular and the fluid inside the cell called intracellular fluids.

It consists of two layers of protein and phospholipids, some protein molecules embadded in them.

Function

It provides protection.

It is selective permeable

It absorbs nutrients.

It excreted wast materials.

Exchange of gases

2. Cytoplasm

It is the fluid present inside the cell. It contains a clear liquid called cytosol, which contains various substance such as protein, carbohydrates, lipids and electrolytes.

3. Nucleus

* The cells with nucleus are called eukaryotes and those cells without nucleus are called prokaryotes.

* Except mature Erythrocytes (RBC) , every cell in the body has a nucleus but Skeleton muscles have several nucleus.

* It consists of two membranes outer and inner.

Nucleus consists of four components___

# Nuclear membrane or nuclear envelope

# Nucleoplasm

# Nucleolus

# Chromatin

4. Mitochondria

It is spherical shaped organelles situated in the cytoplasm. They are called the" power house" of the cell because energy ( ATP adenosine triphosphate) is created here. It is main energy source of the cell consist of inner and outer membrane.

5. Ribosomes

Ribosomes is found in all cell of prokaryotic and eukaryotic. They are not membrane bounded.  It is tiny granules composed of r-RNA and r- Protein.

Function

The main function of ribosome is protein synthesis with the help of ribosomal RNA (r-RNA) , messenger RNA (m- RNA) and transfer RNA (t-RNA)

6. Endoplasmic reticulum

It is  present in almost all eukaryotic cells. It made up of protein and lipids. It is absent in RBC or spermatozoa.

It is of two types_____

Smooth endoplasmic reticulum

* It is an arrangement of tubules and vesicles.

* The size and structure of the SER varies between the cells.

* There are no ribosomes attached to the membrane surface, giving it a smooth appearance.

Function

* It is responsible for synthesis of essential lipids such as phospholipids and cholesterol.

* It is also responsible for production and secretion of steroids of hormones,sex hormones.

* It stores and release calcium ions. These are quite important for the nervous system and muscular system.

Rough endoplasmic reticulum

Ribosomes are present in outer surface of the endoplasmic reticulum, giving it a rough appearance.

It is also called granular endoplasmic reticulum.

Function

It provides site for protein synthesis due to presence of ribosomes.

7. Golgi apparatus

* It is also known as Golgi body, Golgi complex,Golgi .

* It is made up of protein, lipids and several stack of parallel, flattened sac called cisternae. Found in cytoplasm of most eukaryotic cells and absent in prokaryotic, RBCs and sperm cells.

* It has the two poles are cis and trans face responsible for receiving and shipping departments.

* An outer ends of golgi complex, newly modified protein arrives at the trans face of golgi network where it is send off to different parts of the cell via transport vesicles.

Function

It is responsible for______

# Transportation

# Modification

# Packaging

8. Lysosomes

* Lysosome is membrane bound organelle.

* It is spherical sac like structure.

* It is filled with digestive enzymes ( hydrolytic enzymes).

* Enzyme is made up of rough endoplasmic reticulum and Golgi apparatus.

* It helps to clean up digestive foreign material ( bacteria or virus, food,etc).

* It is also known as sucidal bag of the body or recycling machine.

9. Microfilament

* It is thinest form of cytoskeleton.

* It has thread like structure made up of actin protein.

* It helps in muscles contraction.

* It provides structural support, maintain the characteristic shape of the cell.

10. Microtubules

* It is thickest form of cytoskeleton.

* It has tube like hollow structure made up of tubulin protein.

* It helps in movement of material within the cell.

* Microtubules form spindle fibres.

* They form centriole, cillia and flagella.

* It gives shape and support to cell.

 Intermediate filaments

* They have great tensile strength.

* It is made up of kerotin protein.

* It is smaller than microtubules but larger than microfilament.

* It provides mechanical support for the plasma membrane where it comes in contact with other cells or with the extra cellular matrix.

Note:- microtubules, microfilament and intermediate filaments commonly called  cytoskeleton. 

Anatomy part 3

 Organ of special sense

They are:-

Organ of taste - tongue

Organ of sight- eye

Organ of hearing - ears

Organ for tackle sensation - skin

Organ for smell - nose

Cavities of the body

Body cavities are the spaces within the body that help protect , separate and support the internal organs.there are four cavities____

1. Cranial cavity

2. Thoracic cavity

3. Abdominal cavity

4. Pelvic cavity

# Cranial cavities

The eight cranial bones from a hollow space of the head called cranial cavity.It contains brain

Boundaries for of cranial cavity

Anteriorly :-  one frontal bone 

Posteriorly :-  one occipital bones

Superiorly :-  two parietal bone 

Inferiorly :-  one  sphenoid and ethmoid

Laterally :- two temporal bone

# Thoracic cavity

This cavity is situated in the upper part of the trunk.

 Boundaries of thoracic cavity

Anteriorly :- Sternum

Posteriorly:- thoracic vertebrae (12)

Superiorly:- Structure forming root of neck

Inferiorly:- Diaphragm

Laterally:- 12 pair of ribs and intercostal muscles.

Contents

-- Trachea , two bronchi , two lungs

-- Heart , arota , superior and inferior vena cava and other blood vessels.

-- Oesophagus

-- Lymph vessels and lymph nodes

-- Nerves

3. Abdominal cavity

This is the largest cavity in the body and is oval in shape. It is situated in the main part of trunk.

Boundaries of Abdominal cavity

Anteriorly:- anterior abdominal valve muscles

Posteriorly:- posterior abdominal valve muscles and lumber vertebrae

Superiorly:-  Diaphragm

Inferiorly:-  pelvic cavity

Laterally:- lower ribs and parts of lateral abdominal valve.

4. Pelvic cavity

The pelvic cavity is roughly funnel shaped and extends from the lower end of abdominal cavities.

Boundaries of pelvic cavities

Anteriorly:- pubic bone

Posteriorly:- Sacrum and coccyx

Superiorly:- Abdominal cavity

Inferiorly:- Muscles of the pelvic floor

Laterally:- Innominate bones

Anatomy (system of the body)

                    

System of the body

1. Skeleton System :- It is formed by bones. It provide frame work of body.It protects the soft tissues and allows movement of joints.

2. Muscular System :- The muscular system consist of a large number of muscles. They bring about various movements in the body. Muscles are attached to bones, cartilages, ligaments or skin

3. Circulatory System (cardiovascular system):- It includes heart, blood vessels, and blood. This system carry oxygen and nutrients to various tissues of the body.

4. Respiratory System:- It consists of air passage and lungs.It allows exchange of gases between the body and the environment.

5.  Digestive system:- It consists alimentary canal. It is concerned with digestion and absorption of food and elimination of waste material.

6. Endocrine System:- It includes all hormone producing glands and cells such as the pituitary gland, thyroid gland, and pancrease . Hormones regulate body functions.

7. Urinary System:- It consist of kidneys,ureter, urinary, bladder and urithro. It is concerned with the elimination of waste product of the body.

8. Lymphatic System:- It include with immune system or circulatory system because it works closely with both system. The lymph, lymphatic vessels and structure organs containing lymph tissue.It clean and returned tissue fluid to the blood and destroys pathogens that entered the body.

9. Nervous System:- It consist of brain,spinal cord, nervous and sense organ such as the eye and ear. It's function is to give sensory information and regulate body function such as movements.

10. Reproductive System:- It consist genital organ which are different in males and females this system is responsible for the survival of the species by reproduction.

Introduction to anatomical terms

 Anatomy 

Anatomy is a science deals with the structure of the body and relationship of various parts to each other.

Physiology

Physiology is a science that deals with normal functions of the body.It explains how various systems in the body function together normally as a single unit. 

∆A knowledge of the structure is necessary to understand their function.

∆  The subject matter of anatomy include:-

1. Cytology:-the study of cell

2. Histology:-the study of tissue

3. Osteology:- the study of bones 

4. Myology:- the study of muscles

5. Neurology:- study of nervous system

6. Orthology:- the study of joints

The subject matter physiology includes the study of various system like :-

# Cardiovascular system

# Central nervous system

# Digestive system

# Excretory system

# Reproductive system

# Respiratory system

# Muscular system

# Skeleton system

# Lymphatic system

# Endocrine system

There are few important terms which are used to describe the human body.....

Median:- the central plane which divides  the body into two parts i.e right and left.

Medial line:- nearer to the median line.

Lateral:- away from the medial line.

Superior:- nearer to the head.

Interior:- nearer to the foot.

Anterior:-  nearer to the front surface of the body.

Posterior:-  nearer to the back surface of the body.

Proximal:- nearer to the origin of the structure.

Distal:- away to the origin of the structure.

Superficial:- nearer to the skin surface.

Deep :-  deeper from the skin surface.

Movements of Joints 

Elevation:- raising or moving a body parts towards  

cephalic end is termed as elevation.

Depression:- Lowering or moving a body part caudaly is termed as depression.

Protrusion:- It is the forward movement of a body part.

Retraction:- It is the backward movement from the protrusion.

Pronation:-  It is the medical rotation of forearm so that the palm comes to face backward.

Supination:-It is the lateral rotation of forearm so that the palm comes to face anteriorly(forward).

Inversion of foot:- It is the movement that causes the plantar surface of the foot to face inward and downward.

Eversion of foot:- It is the movement that causes the plantar surface of the foot to face laterally and downward.

Flexion:-A movement where similar surface come nearer to each other. This reduces the angle between two bones.

Extension:- A movement where similar surfaces go apart. It is the opposite of flexion. Then angles between two bones is increase.

Rotation :-  A movement around a central axis involving 360 ° angle.

Abduction:- A movement of the bone away from the mid line.

Addiction:-  A movement of the bone towards the mid line.

Circumduction:-  This is the movement of a distal end of a body in a circle.