Anatomy Lecture 03 (General Anatomy) Bone,Function of bone,Classification of bone,Parts of developing long bone,Blood supply,Nerve supply,Bone marrow,Ossification,X-rays

INTRODUCTION

• Bone
• Function of bone
• Classification of bone
• Parts of developing long bone
• Blood supply
• Nerve supply
• Bone marrow
• Ossification
• X-rays

BONE

• A living tissue capable of changing its structure as the result of stresses to which it is subjected
• Adult human body consist of 206 bones
• In a new born baby there are over 270 bones in body
• Branch deals with the study of bones is called osteology

COMPOSITION OF BONE

Bone consist of

• Cells
• Fibers
• Matrix

FUNCTIONS OF BONE

1. Characteristic form to the body – preservation of form
2. Support to human body – mechanical support
3. Protection to vital structures – skull, rib cage
4. Surface of attachments of various structures – tendons, muscles and ligaments.
5. Activity of erythropoises – it is blood forming organ
6. Transmission of sound waves – ossicles of middle ear from ear drum to middle ear
7. Stores Ca and phosphorus – storage organ
8. Maintain electrolyte balance – Ca and phosphate
9. Detoxification – lead, fluorine, arsenic, radium are removed from circulation and deposited in bones and teeth
10. Reticuloendothelial system – defensive system of body
11. Respiration – assist ribs
12. Speech – mandible, hyoid bone, bones of palate.

CLASSIFICATION OF BONE

• Developmental classification
• Structural classification
• Regional classification
• Classification according to size and shape

DEVELOPMENTAL CLASSIFICATION

• Intramembranous
• Intracartilaginous
• Membranocartilagenous

INTRAMEMBRANOUS

• Embryonic mesenchyme directly differentiates into bony tissue
• It occurs in embryo, when bones are urgently required for support and protection

Ø  Bones of vault and skull

Ø  Bones of face

Ø  Clavicle

INTRACARTILAGENOUS

First of all cartilagenous model is formed of bone which later on transforms into bony tissue

• All long bones except clavicle
• Short bones
• Irregular bones

MEMBRANO-CARTILAGENOUS

• At the junction of vault and base of skull the bones are formed by this method

STRUCTURAL CLASSIFICATION

• Compact bone
• Spongy/ Cancellous bone

COMPACT BONE

• Well developed Harversian lamellae or cylindrical lamellae are seen
• Appear as solid mass
• Lamellae consist of collagen fibers, lying in calcified materials

COMPACT BONE

• Adjacent lamellae are held together by interchange of fibers
• Bones cells lie scattered between the lamellae
• E.g., shafts of long bone

SPONGY BONE

• The lamellae are arranged flat
• No harversian system are seen
• E.g., ends of long bone

REGIONAL CLASSIFICATION

• Axial skeleton: 80 bones
• Appendicular skeleton: 126 bones

CLASSIFICATION ACCORDING TO SIZE AND SHAPE

There are five types of bones in the human body

• Long bones:

Found in limbs

Their length is greater then their breath

Have shaft-diaphysis and ends called as epiphysis

• Short bones:

found in hand and foot

They are roughly cuboidal in shape and are composed of cancellous bone.

• Flat bones are thin and generally curved, composed of thin inner and outer layers of compact bone separated by a layer of cancellous bone. e.g. skull bones.
• Sesamoid bones are small nodules of bone found in certain tendons where they rub over bony surfaces. e.g. the patella
• Irregular bones do not fit into the above categories. They consist of thin layers of compact bone surrounding a cancellous interior. e.g. skull, vertebrae and pelvic bones

PARTS OF DEVELOPING LONG BONE

There are 4 main parts of developing long bone:

• Diaphysis
• Epiphysis
• Epiphyseal cartilage
• Metaphysis

DIAPHYSIS

• It resemble the shaft of long bone
• Its ossification center appears in 7^th week of intrauterine life
• Ossification center is primary ossification center

EPIPHYSIS

• It resemble the ends of long bone
• Ossification center usually appears after birth at the age of one or two years
• Except the lower end of femur

EPIPHYSEAL CARTILAGE

• It is the plate of cartilaginous tissue present between epiphysis and diaphysis
• It is represented by epiphyseal line in adult bone

METAPHYSIS

• The actively growing part of shaft close to epiphyseal cartilage is metaphysis
• It is highly vascular
• It is responsible for growth in length

BLOOD SUPPLY OF LONG BONE

• Periosteal arteries
• Nutrient arteries
• Epiphyseal arteries
• Arteries at the end of long bone – periartecular anastomosis
• From the artery passing over that region

NERVE SUPPLY OF LONG BONE

• All bones are supplied by nerves
• They enter the bone through nutrient foramen and periosteum

NUTRIENT FORAMEN

• The nutrient foramen has direction against the growing end
• Towards the elbow we go; from the knee we flee e.g.,
• In humerus the nutrient foramen is directed towards the elbow and upper end of bone is the growing end

BONE MARROW

The marrow cavity is lined by endosteum and contains gelatinous material called bone marrow

Two types of bone marrow:

• Yellow bone marrow
• Red bone marrow

YELLOW BONE MARROW

• It is yellowish gelatinous fibro-fatty mass present in medullary cavity

RED BONE MARROW

It is red gelatinous mass consisting of haemopoietic tissue

It is engaged in erythropoiesis

It is found in:

• Ends of long bone
• Bodies of vertebrae
• Sternum
• Flat bones of skull

OSSIFICATION

The process of bone formation is called as ossification

• Intramembranous ossification
• Intracartilagenous ossification

INTRAMEMBRANOUS OSSIFICATION

• Embryonic mesenchyme directly differentiate into bony tissue.

INTRACARTILAGENOUS OSSIFICATION

• Cartilagenous model of bone is formed that is later on replaced by bony tissue

CENTERS OF OSSIFICATION

• Primary center – appear during fetal life
• Secondary center – appear after birth
• FACTORS AFFECTING BONE GROWTHMinerals – Ca, P etc
• Hormones – PTH, Calcitonin, Growth hormone
• Vitamins – Vit D, Vit C

RADIOGRAPHIC ANATOMY

• X-rays
• CT
• CAT
• MRI

X-RAYS

A tissue that is relatively dense absorbs more x-rays than tissues that are less dense.

• Radiopaque – very dense tissue.
• Radiolucent – less dense tissue.

Anatomy Lecture 02 (General Anatomy) Blood vessel,Lymphatic system,Membranes of body,Cartilage,Joints

TYPES OF SYNOVIAL JOINT

• Plane joint
• Hinge joint
• Pivot joint
• Condyloid joint
• Ellipsoid joint
• Saddle joint
• Ball and socket joint

Synovial Joints

Types of joints	Description	Possible movement	Example
Fibrous	Articulating bones fastened together by a thin layer of dense connective tissues containing many collagen fibers
1.Syndesmosis (Amphiarthrotic)	Bones bounded by interosseous ligament	Joint flexible and may be twisted	Tibiofibular articulation
2.Suture (Synarthrotic)	Flat bones united by sutural ligament	None	Parietal bones articulate at saggital suture of skull
3.Gomphosis (Synarthrotic)	Cone-shaped process fastened in bony socket by periodontal ligament	None	Root of tooth united with mandible
Cartilaginous	Articulating bones connected by hyaline cartilage of fibrocartilage
1.Synchondrosis (Synarthrotic)	Bones united by bands of hyaline cartilage	None	Joint between the first rib and the mandible
2.Symphosis (Amphiarthrotic)	Articular surfaces of bones are covered by hyaline cartilage and the bones are connected by a pad of fibrocartilage	Limited movement, as when the back is bent or twisted	Joints between bodies of vertebrae
Synovial (Diarthrotic)	Articulating end of bones surrounded by a joint capsule; articular bone ends covered by hyaline cartilage and separated by synovial fluid
1.Ball and socket	Ball-shaped head of one bone articulate with cup-shaped socket of another	Movements in all planes( Multiaxial), including rotation	Shoulder, hip
2. Condylar	Oval-shaped condyle of one bone articulate with elliptical cavityof another	Variety of movements in two planes (biaxial) but no rotation	Joints between metacarpals and phalanges
3.Plane	Articulating surfaces are nearly flat or slightly curved	Sliding or twisting	Wrist , ankle
4. Hing	Convex surface on one bone articulate with concave surface of another	Flexion and extension (uniaxial)	Elbow , joints of phalanges
5. Pivot	Cylindrical surfaces of one bone articulates with ring of bone and ligament	Rotation (uniaxial)	Joints between proximal ends of radius and ulna
6. Saddle	Articulating surfaces have both concave and convex  regions; surface of one bone fits the complementary surface of another	Variety of movements, mainly in two planes (Biaxial)	Joint between carpal and metacarpal of thumb

Anatomy Lecture 02 (General Anatomy) Blood vessel,Lymphatic system,Membranes of body,Cartilage,Joints

INTRODUCTION

• Blood vessel
• Lymphatic system
• Membranes of body
• Cartilage
• Joints

BLOOD VESSELS

Blood vessels are of three types

• Arteries
• Veins
• capillaries

ARTERIES

• Arteries transport oxygenated blood from heart and distribute it to various tissues of body by means of their branches
• Arteries do not have valves

ARTERIES

• The joining of branches of arteries is called as an anastomosis
• The wall of an artery is composed of 3 layers
• Tunica intima (inner)
• Tunica media (middle)
• Tunica adventitious (outer)

ARTERIOLES

• The smallest artery is 0.1mm in diameter and is referred as arteriole
• Vessel just proximal to the capillary
• Size varies from 100µm to 12µm

TYPES OF ARTERIES- DEPENDING UPON THE STRUCTURE OF TUNICA MEDIA

Elastic arteries/ large arteries

• Tunica media is composed of elastin

Muscular arteries/ medium arteries/small arteries

• Tunica media is composed of smooth muscle cells

TYPE OF ARTERIOLES – DEPENDING UPON FUNCTION

AFFERENT ARTERIOLES

• Convey blood towards a center
• E.g., afferent arterioles conveying blood towards Bowman’s capsule in kidney (opposite to efferent)

EFFERENT  ARTERIOLES

• Convey blood away from a center
• E.g., efferent arterioles conveying blood away from Bowman’s capsule in kidney

VEINS

• Vessels that transport blood back to the heart
• Carry deoxygenated blood from tissues towards heart
• Many have valves
• The smallest vein are called venules
• Medium sized deep arteries are accompanied by two veins called venae comitants

CAPILLARIES

• Microscopic vessels in the form of a network connecting arterioles to venules
• Pertaining to or resembling a hair
• In tips of  fingers and toes, direct connections occur between arteries and veins without intervention of capillaries
• Site of such connections are referred as arteriovenous anastomosis

TYPES OF CAPILLARIES

• Continuous capillaries

No pores are seen in them- skin, connective tissue, skeletal muscle, lungs, brain

• Fenestrated capillaries

capillaries having endothelial cells linning which show characteristic pore system – renal glomeruli, intestinal villi, endocrine glands, pancreas

• Sinusoids or sinusoidal capillaries

Dilated capillaries lined by reticuloendothelial cells- liver, spleen, parathyroid gland etc

LYMPHATIC SYSTEM

• The lymphatic system is part of a circulatory system, comprising a network of lymphatic vessels that carry a clear fluid called lymph directionally towards the heart
• Lymphatic system is essentially a drainage system and there is no circulation
• Lymph is the name given to tissue fluid once it had entered the lymphatic vessel

COMPOSITION OF LYMPHATIC SYSTEM

• Lymph vessels
• Lymph nodes
• Lymph

LYMPHATIC SYSTEM

• The tonsils, adenoids, spleen and thymus are all part of the lymphatic system
• There are 600 to 700 lymph nodes in the human body
• Nodes filter the lymph before it returns to the circulatory system

LYMPHATIC TISSUE

• Lymphatic tissues are a type of connective tissue that contains large numbers of lymphocytes
• Lymphatic tissue is essential for the immunologic defences of body against bacteria and viruses
• Lymphatic tissue is organized into organs: thymus, lymph nodes, spleen, and lymphatic nodules

LYMPHATIC VESSELS

• Are tubes that assist cardiovascular system in removal of tissue fluid from tissue spaces of body
• Vessels then return fluid to the blood
• They are found in all tissues and organs of body except central nervous system, eyeball, internal ear, epidermis of skin, cartilage and bone

LYMPH CAPILLARIES

• Network of fine vessels that drain lymph from the tissue
• The capillaries are in turn drained by small lymph vessels, which unite to form large lymph vessels
• Before lymph is returned to the blood stream it passes through lymph nodes
• The vessels that carry lymph to lymph node are afferent lymph vessels and that carry away from node are efferent lymph vessels

LYMPH NODES

• Kidney shaped structures
• Vary in size
• Pink in alive persons
• Hilar lymph nodes – black
• Pre-aortic – white in colour
• Dead bodies – brownish

MEMBRANES OF BODY

• Membranes are flat sheets of tissue
• Cover or line parts of the body
• Typically composed of epithelial cells and connective tissue

TYPES OF MEMBRANES

• Mucous membrane
• Serous membrane
• Cutaneous membrane
• Synovial membrane
• Meninges

MUCOUS MEMBRANE

• Also called mucosa
• Line inside of cavities that open directly to exterior environment
• It line gastrointestinal tract, respiratory tract, reproductive tracts and urinary tract
• This type of membrane is composed of an epithelial cell layer and an underlying connective tissue layer

SEROUS MEMBRANE

• Also called serosa
• Line cavities of body that do not open directly to external environment
• Lines chest and abdominal cavities, covers liver, spleen, kidneys, heart etc.
• Made of two layers: a layer to line a cavity, called the parietal membrane, and a layer to cover an organ, called the visceral layer

The cutaneous membrane, also known as skin, covers entire body

• The synovial membrane secretes synovial fluid to lubricate joint space, making motion much easier

MENINGES

• Covering brain is a dense connective tissue membrane, composed of three layers – meninges
• The outer most layer – Dura mater
• The second layer – Arachnoid mater
• The inner most layer – Pia mater

CARTILAGE

• Cartilage is a form of connective tissue in which cells and fibers are embedded in a gel like matrix

TYPES OF CARTILAGE

• Hyaline cartilage
• Fibrocartilage
• Elastic cartilage

HYALINE CARTILAGE

• It has a great resistance to resistance
• Covers the articular surfaces of nearly all synovial joints
• It is incapable of repair when fractured

FIBROCARTILAGE

• Has many collagen fibers embedded in a small amount of matrix
• It is found in discs within the joints e.g. TMJ
• If damaged, it repairs slowly

ELASTIC CARTILAGE

• Posses large numbers of elastic fibers embedded in matrix
• It is flexible
• Found in auricle of ear, epiglottis
• If damaged, repair itself.

JOINTS

• A site where two or more bones come together, whether or not movement occurs between them, is called a joint.
• Joints are classified according to the tissue that lie between the bones.

TYPES OF JOINTS

• Fibrous joint
• Cartilaginous joint
• Synovial joint

SYNOVIAL JOINT

• The articular surfaces of the bones are covered by a thin layer of hyaline cartilage separated by a joint cavity
• The cavity of joint is lined by synovial membrane which extends from margins of one articular surface to other
• The articular surface is protected on outside by a capsule of the joint
• The articular surfaces of synovial joint are lubricated by a viscous fluid called synovial fluid

TYPES OF SYNOVIAL JOINT

• Plane joint
• Hinge joint
• Pivot joint
• Condyloid joint

Anatomy Lecture (What is anatomy,Anatomic position,Surfaces Planes,Movement related to planes,List of basic structures,Skin,Fascia)

INTRODUCTION

• What is anatomy
• Anatomic position
• Surfaces
• Planes
• Movement related to planes
• List of basic structures
• Skin
• Fascia

ANATOMY

• Anatomy is the science of structure and function of the body
• The science of the shape and structure of organisms and their parts

TERMS RELATED TO POSITION

Anatomic position:

• Person standing erect with upper limbs by sides and face and palms of the hands directed forward.

SURFACES

Anterior and Posterior surface:

Front and back of body

Palmar and dorsal surfaces:

In describing hand these terms are used as anterior and posterior

Planter and dorsal surface:

In describing foot these terms are used as anterior and posterior

Proximal and distal surface:

Describe the relative distance from roots of limbs e.g. Arm is proximal and forearm is distal

Superficial and deep:

Relative distances of structures from surface of body

Superior and inferior:

Denotes levels relatively high and low with reference to upper and lower ends of body

Internal and external:

Describe the relative distance of structure from the center of an organ or cavity e.g. Internal carotid and external carotid artery

Ipsilateral and contralateral:

Refers to same side of body or opposite side of body

Supine and Prone:

Position of body lying on back and lying with face forward respectively

PLANES

• Median /Sagittal plane
• Coronal /Frontal plane
• Horizontal /Transverse plane

MEDIAN PLANE

• Vertical plane passing though center of body
• Dividing it into equal right and left halves
• Structure situated nearer to median plane of body than another is said to be medialto other
• Structure that lies farther away from median plane is said to be lateral
• Planes situated to one and other side and parallel to median plane are paramedian

CORONAL PLANE

• Imaginary vertical planes at right angle to the median plane
• Divides the body into anterior and posterior

Horizontal Plane

• Imaginary plane that are at right angle to the imaginary axis
• Divide the body into upper and lower half

MOVEMENT

• The act of moving is known as movement
• There are some terms related to movement in body

–      Flexion, extension

–      Abduction, adduction

–      Medial and lateral rotation

TERMS RELATED TO MOVEMENT

• Flexion: bending movement that decreases angle between two parts of a joint
• Extension: means straightening of joint and usually takes place in posterior direction
• Abduction: movement of limb away from midline of body in coronal plane
• Adduction: movement of limb toward the body in coronal plane

            Rotation: movement of part of body around its long axis

• Medialrotation: movement that results in anterior surface of part facing medially
• Lateralrotation: movement that results in anterior surface of part facing laterally
• Protraction: to move forward
• Retraction: to move backward

LIST OF BASIC STRUCTURES

• Skin
• Fascia
• Muscle
• Joints
• Ligaments
• Bursae
• Blood vessels
• Lymphatic system
• Nervous system
• Mucous membrane
• Serous membrane
• Bones
• Cartilage

SKIN

• Skin is most important organ of body
• It provides protection to internal body parts against harmful substances
• It is divided into 2 parts:

–      Epidermis

–      dermis

EPIDERMIS

• It is stratified epithelium whose cells become flattened as they mature and rise to the surface
• In some areas it is thick and in others it is thin
• In palms and soles of feet it is thick
• In anterior surface of arm and forearm it is thin

DERMIS

• Deep to epidermis is dermis
• It contains many blood vessels, lymphatics and nerves
• It also shows considerable difference in variations in different parts of body

FASCIAE

• It lies between the skin and underlying muscle and bone
• It consist of 2 layers

–      Superficial fascia

–      Deep fascia

SUPERFICIAL FASCIA

• It is the mixture of loose areolar tissue and adipose tissue
• It unites the dermis of skin to underlying deep fascia

DEEP FASCIA

• It is membranous layer of connective tissue that invests muscle and other deep structures
• In joints deep fasciae may be thickened to form bands called retinacula
• Their function is to hold underlying tendons in place

INTERNAL STRUCTURE OF SKELETAL MUSCLE

SKELETAL MUSCLE ACTION

• Prime mover
• Antagonist
• Fixator
• Synergist

MUSCLE TONE

• Muscle tone is major factor controlling stability
• In shoulder joint muscle tone of short muscles around it keeps head of humerus in shallow glenoid cavity
• Without action of these muscles very little force would be required to dislocate the joint

BURSAE

• A bursae is a lubricating device
• It is a closed fibrous sac lined with smooth membrane
• Its walls are separated by viscous fluid
• Bursae are found wherever tendons rub against bones, ligaments or other tendons

COLLAGEN

• The main structural protein of the various connective tissues in animals
• Collagen occurs in many places throughout the body

TYPES OF COLLAGEN

The five most common types are:

• Collagen I: skin, tendon, vascular ligature, organs, bone (main component of the organic part of bone)
• Collagen II:cartilage (main component of cartilage)
• Collagen III: reticulate (main component of reticular fibers), commonly found alongside type I.
• Collagen IV: forms basal lamina, the epithelium-secreted layer of the basement membrane.
• Collagen V: cell surfaces, hair and placenta

                                             Over 90% of the collagen in the body, is type I.