ENSL 3rd Year Unit 4 Structure - PDF

Department of Natural sciences – ENSL – 3rd year (PEM/PES) Unit 4 Structure 1. Look and read: The skeleton consists of two sections- the axial skeleton and the appendicular skeleton. The vertebral column is made up of bony segments called. vertebr...

Department of Natural sciences – ENSL – 3rd year (PEM/PES) Unit 4 Structure 1. Look and read: The skeleton consists of two sections- the axial skeleton and the appendicular skeleton. The vertebral column is made up of bony segments called. vertebrae. The vertebral column is divided into five regions. These regions include the cervical vertebrae. the thoracic vertebrae etc. The bone of the vertebrae surrounds the spinal cord (nervous tissue), which runs through the center of the vertebral column. The skeleton is composed of a hard material called bone, The body is supported by the skeleton. The ribs are attached to the vertebral column. 1 Department of Natural sciences – ENSL – 3rd year (PEM/PES) The limbs are connected to the axial skeleton hy the girdles. The bones in the limbs are joined together. The regions where they join are called joints. Now answer these questions: a) What does the appendicular skeleton consist of'? h) Do the regions of the vertebral column include the ribs? c) What is the hind limb made up of? d) Which part of the hind limb is divided into several small bones? e) Which bones surround the lungs? f) What is the spinal cord composed of? g) What is supported by the cervical vertebrae? h) Which ribs are attached at one end and detached at the other? i) How is the fore limb connected to the axial skeleton? j) Which bone is joined to the pelvic girdle? 2 Department of Natural sciences – ENSL – 3rd year (PEM/PES) 2. Look at this diagram: Now complete these sentences with words from the list: are attached to, consists of, are supported by, include, joint, is connected to, is composed of, are joined to, is divided into. a) The skeleton …………………….. many bones joined together b) These bones …………………….. the skull, the vertebral column, the pelvis, etc. c) The pelvis ……………….. bone tissue. d) The skull and upper parts of the skeleton …………….. the vertebral column. e) The radius and the ulna. ……………. the humerus. f) This ……………... is called the elbow. g) The anterior ends of the ribs. …. ………. the sternum. h) The humerus.. …………. the vertebralcolumn by the spatula. i) The vertebral column. …………….. neck vertebrae. thoracic vertebrae and lumbar vertebrae. 3 Department of Natural sciences – ENSL – 3rd year (PEM/PES) 3. Complele these sentences by saying what the parts are called. Note the new words illustrated by the diagrams: Example: The part of the skeleton that is located above the spine is (called/known as) the skull. a) The large bowl-shaped bone which surrounds the base of the spine …………………… b) The two bones in the lower part of the skeleton which are parallel and detached but joined at each end...................... c) The group of bones which are arranged symmetrically on each side of the vertebral column …………….. d) The long flat bone located at the front of the upper part of the skeleton, to which the ribs are attached …………………. e) The disc-shaped bone which covers the front of the knee joint …………….. f) The bones which are connected by the knee joint ……………… g) The bones which support the pelvis …………. h) The two bones which run horizontally across the top of the ribs …………………... i) The series of bones which make up the spine ………………………. 4 Department of Natural sciences – ENSL – 3rd year (PEM/PES) Look at these examples: Now read this: The structure of plant cells The outer layer of a plant cell is called the cell wall. This is composed of a non-living material called cellulose. The inner surface of the cell wall is lined with a layer of protoplasm. The nucleus is embedded in this layer. The protoplasm which surrounds the nucleus is called cytoplasm. The cytoplasm sometimes contains chloroplasts. These are small bodies composed of protein. The surface of the cytoplasm is covered with a cell membrane. The center of a plant cell consists of a cavity called the vacuole. It is filled with fluid. The walls of a plant cell are often joined to other cells which surround it. The lining between the walls of two cells is called the middle lamella. Now label the parts and composition of a plant cell in this diagram using the following words: middle lamella, cell wall, vacuole, cell membrane, chloroplast, nucleus, cytoplasm, (cellulose) (fluid) (protein). 5