General Anatomy Handouts PDF

# Faculty of Pharmacy ## General Anatomy ### PHL101/MED 101 ### Handouts ## Contents | Topic | Page | |---|---| | Introduction | 1 | | Systems of the body | 5 | | Skeletal system | 6 | | Muscular system | 9 | | Articular system | 16 | | Digestive system | 24 | | Circulatory system | 31 | | Lymphati...

# Faculty of Pharmacy ## General Anatomy ### PHL101/MED 101 ### Handouts ## Contents | Topic | Page | |---|---| | Introduction | 1 | | Systems of the body | 5 | | Skeletal system | 6 | | Muscular system | 9 | | Articular system | 16 | | Digestive system | 24 | | Circulatory system | 31 | | Lymphatic system | 35 | | Respiratory system | 37 | | Urinary system | 40 | | Genital system | 44 | | Nervous system | 48 | | Endocrine system | 54 | | Eyeball and ear | 56 | | Skin | 57 | | Growth of tissues | 58 | ## Introduction ### Anatomy - The science that deals with the structure of the body, (ana means up, tome means cutting). ### Anatomy is divided into: 1. Macroscopic (gross) anatomy: through the dissection of the body and can be divided into regional and systematic anatomy. 2. Microscopic anatomy: using the microscope (histology). ### Anatomical Terms #### Terms of position: 1. Anatomical position: - Standing upright (erect) with the eyes looking horizontally forwards. - The upper limbs are stretched by the sides with the palms facing anteriorly and the thumb is directed laterally. - The lower limbs are straight with the feet close together. 2. Supine position: The position where the body lies on its back. 3. Prone position: The position where the body lies on its face. #### Terms of planes: 1. Sagittal plane: - The vertical plane that passes exactly in the center of the body (median) or parallel to it (paramedian). - *Median plane*: The vertical antero-posterior plane which divides the body into symmetrical right & left halves. 2. Coronal (frontal) plane: - The vertical plane which divides the body into anterior and posterior parts and lies at right angle to the median plane. 3. Horizontal (transverse) plane: - The transverse plane that divides the body into upper and lower parts and lies at right angle to the vertical plane. #### Terms of relations: - **Anterior (ventral):** towards the front of the body or nearer to it. - **Posterior (dorsal):** towards the back of the body or nearer to it. - **Superior (upper – cranial – cephalic – rostral):** towards the head or the upper end of the structure. - **Inferior (lower – caudal):** towards the feet away from the head or the lower end of the structure. - **Medial:** near to the median plane. - **Lateral:** away from the median plane. - **Intermediate:** between medial and lateral positions. - **Proximal:** towards the trunk or the root of the limb. - **Distal:** away from the trunk or the end of the limb. - **Superficial:** near to the surface of the body. - **Deep:** away from the surface of the body. - **Middle:** a position between two points. - **External (outer):** towards the surface of the cavity of the organ. - **Internal (inner):** towards the cavity of the organ. - **Ipsilateral:** the same side. - **Contralateral:** the opposite side. ## Systems of The Body - The human body is formed of cells, tissues, organs, and systems. - The cell is the basic structure of every part of the body. - The tissue is a group of cells of similar shape and function - The different tissues that unite in special way and perform specific function form an organ. - A group of organs that associated to perform certain function form a system. ### There are four main tissues in the body: 1. Epithelial tissue 2. Connective tissue 3. Muscular tissue 4. Nervous tissue ### The human body has the following systems: 1. The skeletal system (bones). 2. The articular system (joints). 3. The muscular system (muscles). 4. The circulatory system. 5. The respiratory system. 6. The digestive system. 7. The genital system. 8. The urinary system. 9. The nervous system. 10. The endocrine system. ## Skeletal System - The study of bones is called (osteology). - The bone is formed of bone cells (osteocytes) and intercellular matrix (collagen fibers, organic and inorganic salts). ### Function of bones: 1. The skeleton gives shape, central axis and support to the body. 2. The bones give protection to the vital organs as the brain, spinal cord and lungs. 3. The bones give attachment to muscles and provide levers for muscles to move the joints. 4. The bones are the major stores for calcium salts. 5. The bone marrow is the main source for blood cells. ### Classification of bones: 1. **Regional:** - Axial (skull & vertebral column) - Appendicular (upper and lower limbs). 2. **Developmental:** membranous, cartilaginous and mixed. 3. **Structural:** compact (hard) and cancellous (spongy). 4. **Morphological:** long, short, flat, irregular and sesamoid. ### Gross anatomy of the long bone: - A long bone consists of shaft (diaphysis) and two expanded ends called epiphysis. - The part of the diaphysis lying close to the epiphysis is called metaphysis. - The shaft (diaphysis) is formed of an outer cortex (compact bone) and a central medullary (marrow) cavity. - The cavity is filled with soft vascular tissues called bone marrow. - The shaft is covered by a fibrous tissue called periosteum which is continuous with the capsules at the two ends of the bone except the articular surfaces. - The epiphysis of the long bone is formed of a cancellous bone covered by a thin layer of compact bone and has a smooth articular surface for the joint. ### Blood supply of the bones: - Nutrient artery: enters the shaft near the middle to reach the medullary cavity then divides into ascending and descending branches. - Epiphyseal and metaphyseal arteries: to the epiphysis & metaphysis. - Periosteal arteries: for the periosteum. ### Nerve supply of the bones: - Bones are supplied by sensory nerves and vasomotor nerves that enter the bone together with the blood vessels. ## Muscular System - Myology means the study of the muscles. - Muscle is a contractile tissue i.e. becomes short in response to a proper stimulus. - The presence of special proteins e.g. actin & myosin and high excitability of the muscle cell are responsible for contractility of muscles. ### Types of muscles: - There are three types of muscles: skeletal (somatic), smooth (visceral) and cardiac. ### (A) Skeletal (somatic or striated) muscle: - The skeletal muscles form about 40-45% of the body weight. - The skeletal muscles are attached to the skeleton and are derived from the somites. - They are voluntary muscles i.e. they contract under voluntary control. - They show marked longitudinal and cross striations. - They are supplied by somatic nerves and therefore under voluntary control. - The skeletal muscle consists of muscle fibers which are arranged in bundles. - The skeletal muscle fiber is multinucleated cell with peripheral nuclei. - The cell membrane is called sarcolemma, the cytoplasm is called sarcoplasm. #### Parts of skeletal muscle: 1. **Origin:** The less mobile end of the muscle during its contraction. It is usually the proximal end in the limb muscles. It may not be single as in biceps, triceps, and quadriceps muscles. 2. **Insertion:** The more mobile end of the muscle and usually the distal end of the limb muscles. Normally, contraction of a muscle approximates the insertion towards the origin, thus producing movement at the related joint. ### Types of attachment: - The skeletal muscles may be attached directly by the fleshy fibers or by a tendon to any of the following structures: 1. Bones: commonest way of attachment 2. Cartilages: e.g. popliteus muscle is attached to the menisci of the knee joint. 3. Deep fascia: muscles of the thigh are inserted into fascia lata. 4. Skin and superficial fascia: muscles of the face. 5. Intermediate tendon or fibrous raphe: e.g. digastric and mylohyoid muscles. ### Forms of muscles: - The muscle fibers are arranged either obliquely or parallel with the line of pull of the muscle (line of pull is the line that extends between the origin and insertion). - Skeletal muscles are classified according to the arrangement of fibers as follows: - *Parallel fibers:* 1. Quadrate: e.g. quadratus femoris. 2. Strap: e.g. sartorius muscle. 3. Fusiform: e.g. lumbericals muscles. - *Oblique fibers:* 1. Unipennate: fibers lie on one side of the tendon. 2. Bipennate: fibers lie on opposite sides of the tendon. 3. Multipennate: muscle fibers are formed of multiple bipennate units close together. 4. Circumpennate: muscle fibers are attached all around the tendon. - There are skeletal muscles with oblique fibers but are not pennate muscles: 1. Triangular: e.g. temporalis muscle. 2. Spiral: e.g. supinator muscle. 3. Cruciate: e.g. masseter muscle. ### Nomination of muscles: - The skeletal muscles are named according to the following: 1. Attachment: e.g. sterno-thyroid muscle 2. Position: e.g. supra-spinatus muscle 3. Shape: e.g. rhomboids muscle 4. Structure: e.g. semimembranosus 5. Action: e.g. extensors, flexors, abductors, supinators, pronators and adductors. 6. Fibers arrangement: e.g. tranversus abdominis muscle 7. Length: e.g. flexor digitorum longus and brevis 8. Size: e.g. Gluteus maximus, medius and minimus muscles. ### Action of muscles: - The action of muscles depends on the length and the number of the active muscle fibers. - The skeletal muscles have a rapid response but easily fatigued. - They are classified according to their action into prime movers (agonists), antagonists (opponents), fixators and synergists. 1. **Prime movers:** The muscles which are responsible for initiation of a particular movement are called prime movers e.gbrachialis initiates flexion of the elbow. 2. **Antagonists:** These are the muscles which oppose the prime movers e.g. triceps opposes the brachialis muscle (triceps muscle is the prime extensor of the elbow). 3. **Fixators (stabilizers):** The muscles which help the prime mover to act efficiently by stabilizing or fixing its origin and the joint upon which it acts. 4. **Synergists:** During contraction of the muscles to move a joint, undesired movements are eliminated by muscles other than the prime mover; those muscles are called synergists. Therefore, synergists help the prime mover to act efficiently on the joint. ### Blood supply of the skeletal muscles: - The muscles receive muscular branches from the surrounding arteries; the fleshy belly is highly vascular while the tendon is less vascular. ### (B) Smooth (none striated – plain) muscle: - The muscle fiber is spindle shaped cell (fusiform), with large, single and central nucleus. - The smooth muscles are innervated by autonomic nerves (sympathetic &parasympathetic), therefore they contract involuntarily. - They respond slowly and not easily fatigued. - They are present in the wall of viscera and blood vessels. ### (C) Cardiac muscle - It is found only in the myocardium of the heart. - It is made of bundles of cells; each has a single central nucleus. - The cells branch and join to form a characteristic network of the myocardium (syncytium). - It shows transverse striations. - The whole heart contracts as one unit. - The cardiac muscle is involuntary muscle supplied by autonomic nerves and is controlled also by special conducting system present in the myocardium. ### Comparison between the muscles: | Muscle type | Skeletal | Smooth | Cardiac | |---|---|---|---| | Site | Attached to skeleton | Viscera & blood vessels | Heart | | Striation | Striated | Non- striated | Striated | | Contraction | Voluntary | Involuntary | Involuntary | | Nerve supply | Somatic | Autonomic | Autonomic | | Muscle cell | Multinucleated | Fusiform with single nucleus | Branch & fuse together |