1. (Articulations)

2. I Can …  … explain how joints are classified into 3 different groups  … describe the basic structure of a diarthrotic joint  … identify different diarthrotic joints based on the different types of motion they allow

3. I. The Need for Joints A A. All bones in the body connect to at least one other bone except one*. * The hyoid bone in the neck to which the tongue is anchored. B. The function of joints is to g gg give us the freedom to move our bodies, or parts of our bodies, in order to maintain our internal environment.

4. II. Kinds of Joints the degree (how much) movement they allow. A. We will be classifying joints based on the degree (how much) movement they allow. synarthroses amphiarthrosesdiarthroses 1. The different types of joints are: synarthroses, amphiarthroses, and diarthroses. determine the degree of movement the joints allow → indirect way of classifying joints. 2. The differences in joint structure determine the degree of movement the joints allow → indirect way of classifying joints. Synarthroses B. Synarthroses are joints that do not allow movement. a joint in which fibrous connective tissue joins bones and holds them together tightly Synarthrosis – a joint in which fibrous connective tissue joins bones and holds them together tightly

6. between cranial bones → good thing since we don’t want our skulls to move and cause damage to our brains. 1. These joints are found between cranial bones → good thing since we don’t want our skulls to move and cause damage to our brains. sutures because they hold bones together like sutures hold damaged tissues together. 2. These types of joints are also known as sutures because they hold bones together like sutures hold damaged tissues together. Amphiarthroses They are formed when cartilage connects the two bones. C. Amphiarthroses are joints that allow slight movement. They are formed when cartilage connects the two bones. slighly moveable joint such as the one joining the two pubic bones Amphiarthrosis – slighly moveable joint such as the one joining the two pubic bones

7. found between the two pubic bones and between vertebrae in the vertebral column 1. These joints are found between the two pubic bones and between vertebrae in the vertebral column strong ligaments, fibrous disks, and a core of pulpy tissue. 2. In the vertebral column, the connective tissue between the vertebrae consist of strong ligaments, fibrous disks, and a core of pulpy tissue. decreases as we get older which is why back problems increase in frequency and intensity as we age a.The elasticity of this connective tissue decreases as we get older which is why back problems increase in frequency and intensity as we age a herniated (slipped) disk if excessive pressure or force causes it to “slip” from between the vertebrae and add pressure on the spinal cord. b.Damage to this connective tissue disk can lead to a herniated (slipped) disk if excessive pressure or force causes it to “slip” from between the vertebrae and add pressure on the spinal cord.

10. Diarthoses D. Diarthoses are joints that allow significant amounts of movement. *Most joints are diarthrotic *Many move bones in more than one direction freely moveable joint Diarthrosis – freely moveable joint 1. The type of movement these joints allow is based on their structure 2. All diathroses have: 1. A joint capsule 2. A joint cavity 3. A layer of cartilage over the ends of the two joined bones

11. made up of strong fibrous connective tissue that fits over the ends of the two bones like a sleeve Joint capsule – made up of strong fibrous connective tissue that fits over the ends of the two bones like a sleeve Ligaments b. Ligaments are made out of the same tough, fibrous connective tissue. band or bands of white fibrous tissue connecting bones Ligaments – band or bands of white fibrous tissue connecting bones Articular cartilage c. Articular cartilage protects the ends of the bones from too much wear and tear. cartilage covering the joint ends of bones Articular cartilage – cartilage covering the joint ends of bones d. Synovial membrane d. Synovial membrane lines the joint cavity secretes a fluid that reduces friction and allows easier movement. A layer of connective tissue that lines the cavities of joints, tendon sheaths, and bursae and makes synovial fluid, which has a lubricating function. Synovial membranes – A layer of connective tissue that lines the cavities of joints, tendon sheaths, and bursae and makes synovial fluid, which has a lubricating function.

13. ball- and-socket, hinge, pivot, saddle, gliding, and condyloid. 3. There are several types of diarthrotic joints: ball- and-socket, hinge, pivot, saddle, gliding, and condyloid. They differ in structure and therefore they differ in function. in our shoulders and hips. a.Ball-and-Socket joints are found in our shoulders and hips. a wide range of directions 1)These types of joints move in a wide range of directions These joints consist of a ball shaped head of one bone that fits into a concave socket of another bone. These joints consist of a ball shaped head of one bone that fits into a concave socket of another bone.

15. in the elbows and knees b.Hinge joints are found in the elbows and knees flexionextension 1)They allow only two types of movement: flexion & extension. act of bending; decreasing the angle between two bones at the joint Flexion – act of bending; decreasing the angle between two bones at the joint increasing the angle between two bones at the joint. Extension – increasing the angle between two bones at the joint.

17. in the second vertebra in the neck and the first vertebra in the neck c.Pivot joints are found in the second vertebra in the neck and the first vertebra in the neck rotate 1)The pivot joint in our neck allows us to rotate our head. movement around a longitudinal axis; for example, shaking your head no. Rotate – movement around a longitudinal axis; for example, shaking your head no. only between the metacarpal bone in the thumb and the carpal bone in the wrist. d.Saddle joints are found only between the metacarpal bone in the thumb and the carpal bone in the wrist.

20. to flex, extend, abduct, adduct, circumduct our thumbs 1)The saddle joint in our thumb allows us to flex, extend, abduct, adduct, circumduct our thumbs BONUS! – we can touch the tips of each finger with our thumb moving away from the midline of the body (opposite motion of adduction) Abduct – moving away from the midline of the body (opposite motion of adduction) moving toward the midline of the body (opposite motion of abduction) Adduct – moving toward the midline of the body (opposite motion of abduction) moving in a circular motion Circumduct – moving in a circular motion we would not be able to pick up a pin or grasp a pencil between our thumb and forefinger 2) Without saddle joints in our thumbs we would not be able to pick up a pin or grasp a pencil between our thumb and forefinger

21. between the vertebra in the spinal column. e.Gliding joints are found between the vertebra in the spinal column. least They allow limited gliding movements. 1)Gliding joints are the least moveable of the diarthrotic joints. They allow limited gliding movements. in the wrist (distal end of radius and the depressions in the carpal bones) f.Condyloid joints are found in the wrist (distal end of radius and the depressions in the carpal bones)