During This 30-Hour Course, Students Will Study the Structure and Function of the Skeletal

Anatomy and Physiology 1 - Subject 2

Subject 2 Anatomy and Physiology I

Learner Guide

Towards Unit of Competency: HLTAP401C and HLTCOM408D

1 Anatomy and Physiology 1 - Subject 2 Contents Page

2 Anatomy and Physiology 1 - Subject 2 Session 2

1) Muscular System o Naming Skeletal Muscles

2) Skull o Bones of the Head o Muscles of the Head

3) Vertebral Column o Divisions and Curvatures o Abnormal Spinal Curvatures o Ligaments o General Structure of a Vertebrae o Intervertebral Discs

4) Muscles of the Vertebral Column - Head and Trunk Movements o Sternocleidomastoid o Scalenes o Splenius o Erector spinae

5) Thoracic Cage o Components (thoracic vertebrae, ribs and sternum) o Muscles of Respiration

6) Abdominal Muscles o Rectus abdominis o External oblique o Internal oblique o Transverse abdominis

3 Anatomy and Physiology 1 - Subject 2 1) Muscular System

The arrangement of skeletal muscles permits them to work either together or in opposition to achieve a wide variety of movements. Muscles can only pull – they never push. Muscle contraction causes shortening, not lengthening, of the muscle, and generally as a muscle shortens, its insertion (attachment on the moveable bone) moves towards its origin (its fixed or immovable point of attachment). Therefore, whatever one muscle (or muscle group) can do, there is another muscle or group of muscles that can "undo" the action.

Origin and Insertion Each muscle begins at an origin, ends at an insertion and contracts to produce a specific action. In general the origin remains stationary, whereas the insertion moves; or the origin is proximal to the insertion.

(Reference Guide: Human Anatomy and Physiology Text, 9th Edition, The Muscular System, Chap 10, Muscle Gallery Table 1-16, p369-418)

Naming Skeletal Muscles

Skeletal muscles are named according to a number of criteria, each of which focuses on particular structural or functional characteristics of a muscle. Paying close attention to these cues can simplify the task of learning muscle names and actions.

(Reference Guide: Human Anatomy and Physiology Text, 9th Edition, The Muscular System, Chap 10, p360)

Make notes on each of the following criteria:

Location of the muscle Number of origins

Shape of the muscle Location of the attachments

Relative size of the muscle Action of the muscle

4 Anatomy and Physiology 1 - Subject 2 Direction of the muscle fibres

2) Skull

The skull is formed by two sets of bones - the cranial bones and facial bones (collectively a total of 22 bones). Additionally, the tiny bones of the middle ear cavity are often counted as skull bones. Most skull bones are flat bones. With the exception of the mandible (which is connected to the rest of the skull by a freely movable joint), all bones of the adult skull are firmly united by interlocking joints called sutures. Colour Label the following diagram of the skull.

(Reference Guide: Human Anatomy and Physiology Text, 9th Edition, The Skeleton, Chap 7, p238)

5 Anatomy and Physiology 1 - Subject 2

Muscles of the Head

Colour code and Label the following muscles of the head:

(Reference Guide: Human Anatomy and Physiology Text, 9th Edition, The Muscular System, Chap 10, Muscle Gallery Table 1, p371)

6 Anatomy and Physiology 1 - Subject 2 3. The Vertebral Column

The vertebral column (also called the spine) is formed from 26 irregular bones connected in such a way that a flexible, curved structure results. Serving as the axial support of the trunk, the spine extends from the skull to the pelvis, where it transmits the weight of the trunk to the lower limbs. Running through its central cavity is the delicate spinal cord. Additionally, the vertebral column provides attachment points for the ribs and for the muscles of the back.

Regions and Curvatures

The vertebral column has five major divisions. The seven vertebrae of the neck are the cervical vertebrae; the next twelve are the thoracic vertebrae and the five supporting the lower back are the lumbar vertebrae. Inferior to the lumbar vertebrae are five fused vertebrae called the sacrum, which articulates with the pelvis. The coccyx is the final part of the vertebral column, formed by four fused vertebrae. All of us have the same number of cervical vertebrae. Variations in numbers of vertebrae in other regions occur in about 5% of people diagram.

(Reference Guide: Human Anatomy and Physiology Text, 9th Edition, The Skeleton, Chap 7, p252-258)

Abnormal Spinal Curvatures There are several types of abnormal spinal curvatures. Some are congenital (present at birth); others result from disease, poor posture, or unequal muscle pull on the spine. Label and describe the following abnormal spinal curvatures.

Please give the definition for the following

Scoliosis

Kyphosis

Lordosis

Ligaments

Tendon

The major supporting ligaments of the vertebral column are the anterior and posterior longitudinal ligaments. These run as continuous bands down the front and back surfaces of the spine from the neck to the sacrum. The broad anterior ligament is strongly attached to both the bony vertebrae and the discs. Along with its supporting role, it prevents hyperextension of the spine (bending too far backward). The posterior ligament, which resists hyperflexion of the spine (bending too sharply forward), is narrow and relatively weak. It attaches only to the discs. Short ligaments connect each vertebra to those immediately above and below.

General Structure of a Vertebrae All vertebrae have a common structural pattern. Each vertebra consists of a body anteriorly and a vertebral arch posteriorly. The disc-shaped body is the weight-bearing region. Together, the body and vertebral arch enclose an opening called the vertebral foramen. Successive vertebral foramina of the articulated vertebrae form the vertebral canal, through which the spinal cord passes. Additionally, vertebrae exhibit variations that allow the different regions of the spine to perform slightly different functions and movements.

(Reference Guide: Human Anatomy and Physiology Text, 9th Edition, The Skeleton, Chap 7, p254 & 257)

Intervertebral Discs Each intervertebral disc is a cushion-like pad composed of two parts. The inner semifluid acts like a rubber ball to give the disc its elasticity and compressibility. Surrounding the fluid and limiting its expansion is a strong outer collar of collagen fibres and fibrocartilage. The outer layer also holds together successive vertebrae and resists tension in the spine. The discs act as shock absorbers during walking, jumping and running and allow the spine to flex and extend, and to a lesser extent, bend laterally.

Muscles of the Vertebral Column – Head and Trunk Movements

Draw the following muscles on the skeletal diagram (over page) and identify their origin, insertion and action.

· Sternocleidomastoid · Scalenes · Splenius · Erector spinae · Quadratus lumborum

(Reference Guide: Human Anatomy and Physiology Text, 9th Edition, The Muscular System, Chap 10: Sternocleidomastoid, Scalenes & Splenius p376; Erector spinae & Quadratus lumborum p378.

Muscle Origin Insertion Action

Sternocleidomastoid

Scalenes

Splenius

Quadratus lumborum

Erector spinae General description:

12 Anatomy and Physiology 1 - Subject 2 4) Thoracic Cage

Elements of the thoracic cage include the thoracic vertebrae (dorsally), the ribs (laterally) and the sternum and costal cartilages (anteriorly). The thoracic cage forms a protection around the vital organs of the thoracic cavity (heart, lungs and great blood vessels), supports the shoulder girdles and upper limbs, and provides attachment points for many muscles of the neck, back, chest and shoulders. In addition, the intercostal spaces between the ribs are occupied by the intercostal muscles, which lift and depress the thoracic cage during breathing. Label the following diagram of the Thoracic Cage.

(Reference Guide: Human Anatomy and Physiology Text, 9th Edition, The Skeleton, Chap 7, p258 & 260)

Muscles of Respiration

Two main layers of muscles (extending from one rib to the next) help form the anteriolateral wall of the thoracic cage. The external intercostal muscles form the more superficial layer. They lift the rib cage (inspiratory muscles). The internal intercostal muscles form the deeper layer and aid active (forced) expiration. The alternating contraction and relaxation of the diaphragm causes pressure changes in the abdominopelvic cavity that facilitates the return of blood to the heart.

(Reference Guide: Human Anatomy and Physiology Text, 9th Edition, The Muscular System Chap 10, Muscle Gallery, Table 5, p380-381).

14 Anatomy and Physiology 1 - Subject 2 5) Muscles of the Abdominal Wall

Draw the following muscles on the skeletal diagram (over page) and identify their origin, insertion and action.

· Rectus abdominis · External oblique · Internal oblique · Transverse abdominis

Human Anatomy and Physiology Text, 9th Edition, The Muscular System, Chap 10, Muscle Gallery, Table 6, p382-383.

Muscle Origin Insertion Action

Rectus abdominis

External oblique

Internal oblique

Transverse abdominis