Anatomy Lecture 04 (General Anatomy)

Anatomy Lecture 04 (General Anatomy) Stability of synovial joints,Nervous system,Central nervous system,Peripheral nervous system,Autonomic nervous system,Structures related to muscles

INTRODUCTION

• Stability of synovial joints
• Nervous system
• Central nervous system
• Peripheral nervous system
• Autonomic nervous system
• Structures related to muscles

TYPES OF SYNOVIAL JOINT

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

STABILITY OF SYNOVIAL JOINTS

The stability of a joint depends on three main factors:

• The shape size and arrangement of articular surfaces
• The ligaments
• The tone of muscle around

ARTICULAR SURFACES

• Bone shape plays an important role in joint stability
• Ball and socket arrangement of shoulder joint
• Mortise arrangement of ankle joint

LIGAMENTS

• A cord or band of connective tissue uniting two structures
• Commonly found in association with joints

TYPES OF LIGAMENTS

Ligaments are of two types

• Fibrous ligaments
• Elastic ligaments

FIBROUS LIGAMENTS

• Composed of dense bundles of collagen fibers
• Unstretchable normally
• Prevent excessive movement in a joint
• If the stress continues for an excessive long period then fibrous ligament stretch

ELASTIC LIGAMENTS

• Composed largly of elastic tissue
• Can return to the original length after stretching

NERVOUS SYSTEM

• It is responsible for transmitting and receiving electrical and chemical signals within body
• It together with endocrine system controls and integrate activities of different parts of body

NERVOUS SYSTEM

It messages through

• Afferent neurons
• Efferent neurons
• Interneurons

AFFERENT NEURON

• Neurons that send signals from peripheral nervous system (arms and legs) to spinal cord
• And onto cerebral cortex also

 EFFERENT NEURON

• Neurons that send messages from cerebral cortex  to muscles and various organs in body
• Achieve a desired response

CENTRAL NERVOUS SYSTEM

• It integrates information, coordinates and influences activity of, all parts of body
• CNS consist of large numbers of nerve cells and their processes
• Supported by specialized tissue called neuroglia

NEURON

• Neuron is a term given to nerve cell and its processes
• The neuron has a cell body and two types of processes, dendrites and axon

PERIPHERAL NERVOUS SYSTEM

• The peripheral nervous system (PNS) is part of nervous system
• It consists of nerves and ganglia outside of the brain and spinal cord
• Main function of PNS is to connect CNS to limbs and organs
• Serves as a communication relay going back and forth between brain and extremities

PLEXUSES

• Interconnection between spinal nerves
• When ventral rami of 2 or more then 2 spinal nerves interconnect with each other they form nerve plexus

PLEXUS IN BODY

• Cervical plexuses
• Brachial plexuses
• Lumbar plexuses
• Sacral plexuses

AUTONOMIC NERVOUS SYSTEM

• The autonomic nervous system (ANS), also known as visceral nervous system and involuntary nervous system
• It is part of nervous system that controls involuntary actions
• Beating of your heart
• Widening or narrowing of your blood vessels etc

STRUCTURES RELATED TO MUSCLE

• Tendon
• Aponeurosis
• Tendon-synovial sheaths
• Raphes

TENDON

• Tough whitish cords
• Inextensible
• Varying in length and thickness
• Comprise of parallel fascicles bundles of collagen fibers and tendon cells.

POINT OF ATTACHMENT OF TENDON

• Endotendon: It blends with the periosteum
• Collagen fiber component: pass through cortical bone

FUNCTION OF TENDON

• Connect the muscles with bone and cartilages
• Move the parts of body

APONEUROSIS

• White fibrous tissue
• Flattened and expanded sheets
• Supplied with blood vessles
• Parallel within and inclined in different directions

TENDON-SYNOVIAL SHEATHS

• A synovial sheath is a tubular bursa surrounds a tendon
• The tendon invaginates the bursa from one side

RAPHES

• A linear fibrous band
• Formed by interdigitation of the short tendinous ends of muscle fibers