Animal Anatomy PDF

2. Classification of bones according to their shape. Long bones- these are typical of the limb bones, ex, femur, humerus and also include bones of the metacarpus. Long bones have a shaft containing a medullary cavity filled with bone marrow. Flat bones- these have an outer layer of compact bone with a...

2. Classification of bones according to their shape. Long bones- these are typical of the limb bones, ex, femur, humerus and also include bones of the metacarpus. Long bones have a shaft containing a medullary cavity filled with bone marrow. Flat bones- these have an outer layer of compact bone with a layer of cancellous or spongy bone inside, there is no medullary cavity, eg, flat bones of the skull, scapula and ribs. Short bones- These have an outer layer of compact bone with a core of cancellous bone and no medullary cavity, eg, carpal and tarsal bones. Irregular bones- weird shaped, kind of similar to short bones in structure but a less uniform shape, they lie in the midline and are unpaired. Specialized types of bones: Sesamoid bones- These are sesame-seed shaped bones that develop within a tendon (and occasionally a ligament) that runs over an underlying bony prominence, they serve to change the angle at which the tendon passes over the bone and thus reduce “wear and tear” eg, the patella associated with the stifle joint. Pneumatic bones- These contain air filled spaces known as sinuses which have the effect of reducing the weight of the bone, eg, maxillary and frontal bones. 3. Fibrous and cartilaginous joints – classification, explanation, and examples. Fibrous joints- Connects bones with dense fibrous connective tissue, and are mostly immovable like the sutures of the skull bones. Cartilaginous joints- Unite bones using cartilage, and are similar to their fibrous brethren in that they don’t move very much, and they lack a joint cavity 4. Structure of synovial joints. It is movable, and consists of a joint cavity, articular cartilage, and joint capsule with an inner synovial membrane and an outer fibrous layer. Ligaments- in relation to the musculoskeletal system are connective tissue bands that extend from bone to bone. Meniscus- Is fibrocartilage that partially or completely divides a joint cavity. They serve to make the joint more stable by improving the fit bw two articulating bones Synovial joints- Are freely movable joints. They do make use of cartilage and fibrous connective tissues like ligaments, they are different in that the bones they join are separated by a fluid-filled joint cavity. Synovial fluid- act like a grease on a hinge 5. Types of synovial joints (according to the number of the bones; degree, and kind of mobility; and the form of articular surfaces). 6 different configurations: Plane joint- When one flat bone surface glides over another Hinge joint- If the bending motions decrease the angle of the joint and bring those bones together that movement is called flexion. When it bends back it increases that angle and it's called extension. If that motion is bent too much which could be dangerous, that is called hyperextension. Condylar joint- Allows for example fingers to move. Ball and socket joint- Hip and shoulder joints use this type of joint, which is a design that allows rotational movement, but the more flexible a joint is, the more unstable and fragile it is, which is one of the reasons why so many organisms have dislocated shoulders and hip replacements. Saddle joint- Opposition movement, which makes the thumbs opposable. Pivot joint- Allows to rotate palm forward or anteriorly (supination) and turning it backwards or posteriorly (pronation) Ellipsoid joint- Distal bone has an ovoid articular surface and is received into an elliptical cavity, which makes it impossible for the bones to do axial rotation. So the main movements here are flexion-extension, adduction,abduction and circumduction. Mobility: Flexion/ extension- these are antagonistic movements of a joint. Flexion- reduces the angle bw two bones eg, bends the limb Extension- increases the angle bw two bones ex, straightens the limb Abduction/ adduction- these movements affect the whole limb Abduction- Means to “take away” moves a body part away from the median plane or axis eg, moving the leg out sideways Adduction- moves a body part back towards the central line or axis of the body eg, moving the leg back to standing position Rotation: The moving body part “twists” on its own axis. It rotates either inwardly or outwardly Circumduction- the movement of an extremity. One end of a bone, in a circular pattern. Gliding/sliding- the articular surfaces of the joint slide over one another. Protection- the animal moves its limb cranially- Advances the limb forward, as when walking. Retraction- the animal moves the limb back towards the body. 6. Forms of muscles. Classification of muscles (by number of the joints; by a functional effect). Most muscles have attachments to 2 bones (some muscles are attached to soft tissue eg, skin. Traditionally the less mobile attachment is called the origin and the more movable attachment is called insertion. Ex, the musculus biceps brachii extends from the scapula to the radius. The scapula usually moves less than the radius during contraction of the biceps so the origin of the biceps is its attachment to the scapula, and the insertion is its attachment to the radius. 7. Accessory structures of muscles (fasciae, tendon sheath and bursae). Fasciae- are connective tissue sheets that surround and separate muscles, organs, and other structures providing support and reducing friction. Tendon- Are tubular coverings around certain tendons, mainly in the hands and feet that contain synovial fluid to lubricate and protect tendons as they move. Bursae- are small, fluid-filled sacs located bw bones and soft tissues like tendons or muscles, acting as cushions to reduce friction and prevent irritation during movement. 8. Thoracic cavity – the structure of the walls, mediastinum, and pleura. The organs in the thoracic cavity, and the organ system they belong to. Thoracic cavity: the space within the chest that houses vital organs. It is bounded by: - Walls: The rib cage (including ribs and sternum), thoracic vertebrae, and muscles, which provide structure and protection. - Mediastinum: The central compartment bw the lungs containing the heart, trachea, esophagus, thymus and major blood vessels. It serves as a partition and supports these structures. - Pleura: A double-layered membrane covering the lungs (visceral pleura) Organ in the thoracic cavity: - Lungs (respiratory system): Responsible for gas exchange  - Heart (cardiovascular system): Pumps blood throughout the body - Trachea and bronchi (Respiratory system): Conduct air to the lungs - Esophagus (Digestive system): Transports food from the throat to the stomach - Thymus (Lymphatic/ immune system): Plays a role in immune function, particularly in children 9. Abdominal cavity – the structure of the walls, the anatomical regions, the peritoneum. The organs in the abdominal cavity, and the organ system they belong to. Abdominal cavity: Is the space within the abdomen that contains digestive, excretory, and other organs. It is structured as follows: - Walls: The abdominal cavity is bounded by the abdominal muscles, vertebral column, diaphragm (above), and pelvic bones (below). These structures provide support and protect internal organs. - Anatomical regions: Divided into nine regions(ex, epigastric, umbilical, hypogastric) or four quadrants to help locate organs and structures. - Peritoneum: A double-layered membrane that lines the cavity. The parietal peritoneum covers the cavity walls, while the visceral peritoneum covers the organs. This membrane supports the reduced friction bw organs. Organs in the abdominal cavity: Stomach, intestines, liver, gallbladder, pancreas (digestive system): Involved in the digestion, absorption and processing of nutrients. Kidneys, uterus (urinary system): Responsible for filtering blood and producing urine. Spleen (Lymphatic/ immune system): Filters blood supports immune system Adrenal glands (endocrine system): Produce hormones, including adrenaline and cortisol. 10. Pelvic cavity – the structure of the walls, the anatomical regions, the peritoneum. The organs in the pelvic cavity, and the organ system they belong to. Pelvic cavity: Is the space within the pelvis that houses reproductive, urinary and some digestive organs - Walls: bounded by the pelvic bones, sacrum, coccyx, and various muscles, which provide structural support and protection. - Anatomical regions: The pelvic cavity is often divided into the greater (false) pelvis (above the pelvic brim) and lesser (true) pelvis (below the pelvic brim), which contains the pelvic organs. - Peritoneum: The peritoneum covers organs in the pelvic cavity. The visceral peritoneum covers some organs, while the parietal peritoneum lines portions of the cavity. It provides support and lubrication. Organs in the pelvic cavity: - Bladder, urethra (urinary system): involved in the storage and excretion of urine - Rectum (digestive system): Stores feces before elimination - Reproductive organs: - Male: Prostate, seminal vesicles (reproductive system) - Female: Uterus, ovaries, fallopian tubes (reproductive system) 11. Biosafety: a. Anatomy and Physiology Department Biosecurity Standard Operating Procedures (Chapter 3). b. Procedures in Dissection Classes