Obalectures

By Oba Mike Introduction Connective tissues are the most abundant tissues in the body. As the name suggests, the major function of connective tissue is to bind together, support and strengthen cells and other body tissues. Functions of Connective tissues 1. They give structural and functional support to cells and other tissues. 2. Protection and defense against pathogens. 3. Stores energy. 4. Transport of substances within the body. 5. Insulation. Structure of Connective Tissues Connective tissues consist of two basic elements: 1. Cells 2. Extracellular matrix Cells Connective tissue cells originate from embryonic cells called mesenchyme . The cells vary according to the type of tissue and include the following: A. Fibroblasts B. Adipocytes (fat cells) C. Macrophages D. Mast cells E. Blood cells ( erythrocytes, leukocytes, thrombocytes). Fibroblasts They are large flat cells with branching processes. They are the most numerous connective tissue cells and are present in all the general

By Oba Mike NOTE: This note goes with the slides. There are clearer pictures in the slide for you to view and draw. Introduction A tissue is a group of cells that function together to carry out specialized activities. Cells of a particular tissue usually have a common embryonic origin. The structure and functioning of a tissue are influenced by factors such as: i.  The nature of the extracellular material that surrounds the tissue cells. ii. The connections between the cells that compose the tissue. Tissues exist in different forms, hard e.g bone, semisolid e.g fat, liquid e.g blood. The branch of anatomy that deals exclusively with the study of tissues is termed histology . Pathology is the branch of medicine concerned with diseases of cells and tissues. Types of tissues Body tissues can be classified into four types according to their structure and function: 1. Epithelial tissues 2. Connective tissues 3. Muscular tissues 4. Nervous tissues For now, we will focus only on epithelial a

By Oba Mike Introduction Spermatogenesis is the formation of spermatozoa (sing. Spermatozoon) in the seminiferous tubules of the testis. It takes place during the reproductive period, which begins at the age of puberty (12-16years) and continues even to old age. Location It occurs in the seminiferous tubules of the testis. Duration 64 - 74 days Stages Spermatogenesis can be divided into three stages: 1. Spermatocytosis 2. Meiosis 3. Spermiogenesis Spermatocytosis Spermatocytosis is the conversion of a spermatogonium (stem cell) into primary spermatocyte . It marks the beginning of spermatogenesis. Spermatogonia are stem cells located in the walls of the seminiferous tubules near the basement membrane. These cells are similar to oogonia in the ovary and arise from primordial germ cells that migrated from the yolk sac.  Each spermatogonium is diploid and contains 46 chromosomes (44+X+Y) . Prior to the division into primary spermatocyte, the spermatogonium first divides into type A and t

By Oba Mike Image credit: sites.google. com Introduction The bony pelvis or simply pelvis is a basin-like structure composed of the hip bones, pubic symphysis, sacrum and coccyx. Functionally, the pelvis provides support to the vertebral column, pelvic and lower abdominal organs. It also connects the bones of the lower limbs to the axial skeleton. Functions of the Pelvis 1. Supports the vertebral column. 2. Protects pelvic and lower abdominal organs. 3. Connects the bones of the lower limbs to the axial skeleton. 4. Transmits the weight of the body to the lower limbs while standing and to the seat while sitting. 5. Helps in the attachment of several muscles. 6. Supports childbearing in females. Components of the Bony Pelvis The bony pelvis is formed by four different structures: 1. 2 hip bones (pelvic girdle) 2. Pubic symphysis  3. Sacrum 4. Coccyx Hip bones The hip bones also called pelvic or coxal bones are the two bones that form the pelvic girdle. They form the anterior and latera