Case Study 1: Bone
Harry and Sally, a couple in their late 60’s, were driving to the supermarket to do the groceries. As they pulled up at a set of traffic lights, the car behind them did not stop, hitting them and throwing them both from the car. Harry walked away relatively unscathed, only a few bruises. Sally on the other hand ended up with a broken hip.
Case Study 1: Bone
1. List and briefly describe the four types of bones cells
According to the case study, Sally suffered from broken hip and bones cells were ruptured in the hip bone area. Four types of bone cells are Osteoprogenitor, Osteocytes, Osteoblasts and Osteoclasts. Osteoprogenitor cells are the stem of the bone cells, which originated from mesenchyme. It can go cell division and situated in the periosteum’s inner layer1. Osteoblasts are the building cells of bone that secretes osteoid for forming extracellular bone matrix. Osteocytes are the mature cells that are located inside the lacunae and communicate through canaliculi. Osteoclasts are dissolving cells comes out from white blood cells that releases acids and enzymes to soften bone.
2. Despite both Harry and Sally being hit by the same force, and from the same angle, speculate a physiological mechanism why Sally (being female) ended up with a broken bone, but Harry (a male) was relatively unharmed?
The same force as Harry hit Sally, but Sally suffered from a broken hip due to the physiological causes. Moreover, Sally has different hip bone structure compared to Harry because she is female. In the perspective of a female, hip bone in the pelvic region forms pelvic girdle that is located in pairs. This hip bone possesses curved and large bones in the anterior and lateral region in the pelvic region, which separates after teenage2. Thus, this causes the bone to be separated into smaller bones. Further, any type of forces can rupture the bone easily due to the complicated structure of hip bone in the pelvic region.
3. Sally has been instructed to stay off her feet for the next 8 weeks to allow her hip to heal. List the steps involved in fracture repair
Hip repair deals with the mobilization of broken bones with the help of surgical nails, screws, plates and rods. Moreover, Sally had gone through the step of the fracture healing process 8 weeks to stand up on her feet. In the repairing of the hip bone, the process includes rehabilitation, medication and surgery. Further, in the internal healing process, the bone goes through the Reactive phase, two Reparative phase and Bone Remodeling Phase2. In the reactive phase, hematoma fracture is formed at periosteum. In the reparative phase, formation of fibro cartilaginous callus occur and then soon after bony callus forms at Spongy Bone trabeculae. At the last phase of Bone Remodeling, fractured bone heals under the Bony callus that is hard.
4. During the rehabilitation process, Sally was finding it difficult to get back into swimming, her preferred form of exercise. Harry suggested that she start attending the gym with him. Why might have swimming contributed to Sally suffering from a break, and would resistance training benefit Sally?
In the time of the rehabilitation process, Sally could not attend the swimming because Sally could have experienced pain in the hip bone, which can damage the fractured hip bone again. Thus, in the rehabilitation process, exercise is the stage, which probably provides strength to the hip region by focusing on the strengthening and range of motion exercises. Physical therapists can provide an exercise calendar to do exercise daily in order to enhance internal fixation bones. Moreover, walking for a continuous 4 to 6 weeks can heal the hip bone after treatment of fracture quickly. Thus, Sally was benefited by gym facilities compared to the swimming.
5. To reduce the risk of bone fracture in the future, Sally decided to begin taking a calcium supplement. Describe the process of calcium regulation in the blood
In order to execute the treatment of hip bone fracture, calcium supplement was provided to Sally that was regulated in the blood by parathyroid hormone. While intake of calcium dose daily, calcium regulation in the blood level is enhanced by parathyroid hormone. The parathyroid hormone helps to regulate the calcium level in the blood by maintaining it high or low as per the dosage of person4. It helps to stimulate osteoclasts by breaking the calcium to bloodstreams. Further, blood calcium level enhances calcitriol formation by absorbing the calcium and calcitonin helps to excrete calcium via urine.
1. Many anaesthetics work by making it harder for a neuron to reach threshold. Describe, in detail, the four stages of an actional potential
Action potential has four stages in neuron transmission are resting potential, re-polarized, depolarization and again to resting potential. In case of resting potential, the potential latent membrane lies inside the inactive cells. Additionally, polarization in the neuron mechanism determines the spatial difference of the nerve cells in the context of structure, function and shape. This cell exerts polarity, which enhances the special function. Depolarization is the stimulus that starts in the cell membrane containing positively charged sodium ions5. Repolarisation is the electric gradient that exerts the threshold in which downswing started in the ionized channels. Back to the resting potential stage means to be refractory phase in which neuron goes back to rest state.
2. Under a general anaesthetic, a patient is largely paralysed. Considering neural pathways, does the ascending or descending pathway control skeletal muscle movement? And what is this tract called?
Yes, the descending or ascending pathway controls skeletal muscle movement in neural pathways. The tract in which the descending motor pathway occurs is known as the lateral corticospinal tract. Ascending pathway activates stimuli by CNS for controlling electrical impulses in the neck and head travel of receptor neuron by sensory pathway. Descending path travels down by electrical impulse between the corticobulbar tract and corticospinal tract via effector that is spinal cord. It forms brainstem at the spinal cord. This function operates in the region of lower medulla which includes decussates and cerebral cortex in the pyramid. Inside medulla oblongata, brain nerves process the descending pathway to the contralateral side.
3. To ensure that the anaesthetic was working before beginning the surgery, the attending anaesthetist tested Amy for the plantar reflex. What is a reflex, and give an example describing the stimulus, receptor, neural pathway and response
The reflex arc acts in five steps motor neuron, sensory receptors, integrating center, sensory neuron and effectors. Primarily sensory receptor respond against the stimulus through producing receptor potential or generator, then as sensory neuron axon conducts the impulses in between receptor to the integration center. Integrating center of CNS relay impulses from sensory to motor neurons and the integration from center to effectors enhances, based on which gland or muscle responds. Moreover, the reflex action is the mechanism that is controlled by the conscious part of the brain to formulate the reflex movements6. Stimulus is the result of reaction, energy or excitement. For example, the baby sees a shining object. Receptor is the chemical structures that receives or transmit signals, for example, β-adrenergic receptor. Neural pathway is the path that connects the nervous system by one another via tract, for example, optic nerve. Response from the nerve cells comes after a specific reaction, for example, ink blotting on paper.
4. Three days into her recovery, Amy goes back to the hospital with numbness in her injured foot and an inflamed scar. Describe a physiological reason how residual anaesthetic may cause numbness in Amy’s foot
Numbness in foot can be caused by residual anesthetic that lasts for long hours or even a day. It can be caused in the person due to the severe pain or cut on the lower part of the leg in which sensory receptors does not work. Moreover, while going through the residual anesthetic process, surgery is done on the foot7. Similarly, visceral and somatic senses can lead to numbness in body occurs that can be experienced temporary in the lower leg. The person suffers from severe pain due to nerve damage for that anesthesia was performed on blocked nerve.
5. The doctors also believe that Amy’s scar is infected. Name and describe a structural mechanism that protects the central nervous system from infection
Spinal cord and brain form central nervous system, which protects the structural mechanism during infection. Moreover, using the mechanical process, the living nerve tissue protects from the physical damages of the brain. Cerebrospinal fluid provides the brain with special structure along with protective chemical environment that helps to protect from buoyancy and shock absorption8. Further, barrier of blood brain helps to protect by impermeable capillaries and semipermeable membranes. Moreover, automatic and somatic peripheral system generates the process for the structural mechanism, which expands the central nervous system to the muscle fiber in vertebra