Higher Order Structures and Homeostasis

April 13th, 7:30 AM

Prometaphase

- Nuclear envelope disassembles

- Chromosome forms two kinetochores at the centromere

- Microtubules attach to the chromosomes

Metaphase

- Chromosomes align along the metaphase plate

Anaphase

- Chromatids separate towards opposite poles

Telophase

- New nuclear envelope forms

- Chromosomes unfold back into chromatin

- Nucleoli reappear

- Cell continues to elongate

Cytokinesis

- Daughter cells divide along the cleavage furrow (in animal cells) or cell plate (in plant cells)

Apoptosis- Programmed cell death

Unit 7: HIGHER ORDER STRUCTURES deals with larger structures in the body made up of cells that perform a similar function. This unit overviews tissues, organs, organ systems, the body, and populations.

Tissue- A group of cells with a similar shape and function

- There are four main types of tissues

1. Muscle tissue (both skeletal, smooth, and cardiac) is contractile. It allows locomotion of the body and necessary contractions of organs like the heart.

2. Nerve tissue comprises the body's wiring system. It conducts signals between the nervous system and various organs.

3. Connective tissue holds the body together. It is found in most organs, anchoring them to the skeleton and other organs. It includes fatty tissue, loose tissue, cartilage, etc.

4. Epithelial tissue protects the body against the outside environment. Skin tissue helps maintain homeostasis by monitoring and controlling temperature and resisting abrasion, foreign bodies, and damaging chemicals.

- Form during development from stem cells

Organ- Made up of tissues that work together to perform a specific function for the body as a whole

Organ system- Made up of organs that work together to perform a more general function for the body

The body- Maintains proper physiological functions through the cooperation of organ systems

Populations- External forces can impact physiology and health

Unit 8: HOMEOSTASIS AND FEEDBACK LOOPS defines homeostasis as the tendency of biological systems to maintain relatively constant conditions in the internal environment while continuously interacting with and adjusting to changes originating within or outside this system. One interesting example given to illustrate this is physical exercise, which I noted because exercise science goes hand in hand with kinesiology.

In physical exercise:

- Muscle cells use oxygen to convert glucose to ATP which drives muscle contractions; thisis why you breathe heavier

- Your heart pumps faster to deliver more oxygen-rich blood to your muscles and other organs

- During cellular respiration, the muscle cells produce carbon dioxide and water as waste products to be eliminated through breathing

- A byproduct is heat, so your body compensates by causing blood vessels near your skin to dilate and causing sweat to cool you down

Along the same lines, a feedback loop is any system used to control the level of a variable in which there is an identifiable receptor, control center, effectors, and method of communication. Variables are the parameters that are monitored and controlled/affected by the feedback system. Receptors, or sensors, detect changes in the variable. Control centers, or integrators, compare the variable in relation to a set point and signal the effectors to generate a response. In turn, the effectors execute the necessary changes to adjust the variable. The body typically communicates these signals through nerve action potentials or the relase of hormones.

A feedback cycle is any situation in which a variable is regulated and the level of the variable impacts the direction in which the variable changes, even if the loop components are not clearly identifiable.

Feedback is a situation when the output or response of a loop impacts or influences the input/stimulus.

End: 8:30 AM

#anatomy #cells #capacitybuilding #seniorproject #physiology #homeostasis