biology 121 Essay

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Bio 110
Essential life processes
1. Metabolism – The sum of all catabolic (breaking down) & anabolic (building up) processes that occur in the body.
2. Responsiveness – the body’s ability to detect and respond to changes.
3. Movement – any form of motion including movement of the tiny sub cellular structures, or some movement inside of the cells.
4. Growth – increase in body size and this occurs due to an increase in the size of cells, number of cells or both factors combined.
5. Differentiation – development of a cell from an unspecialized to a specialized state.
6. Reproduction – formation of new cells in the form of growth, repair or replacement or the production of a new individual.

Human Anatomy – study of the body structure.
Human Physiology – science of body functions.

Levels of Organization
Smallest to Largest –
Chemical level: Atoms, inorganic/ organic molecules
Cell: Basic structural and functional unit of an organism
Tissues: Groups of cells that work together to perform a similar function. 4 Different Types: Epithelium-covers outside surfaces, connective-connects/supports/protects, muscle-responsible for movement and heat generation, nerves-carry information throughout the body
Organs: Structures that are composed of two or more different types of tissues. Ex) Hearts, liver, bones
Organ System: related organs with a common function Ex) digestive system
11 organ systems:
Cover these four
Organism: Collection of organ systems

A condition of equilibrium in the body’s internal environment. Aiming to keep the body functions within the narrow range that is compatible with life.

Being challenged by:
Physical insults-intense heat, lack of O2
Changes in internal environment- drops in blood glucose ie) not eating
Physiological stress- demands of work and school

Feedback System
Three basic components: Receptors-, control center, effector Ex) Body temp

Negative Feedback System
Reverses a change in a controlled condition Ex) Body temp. Closer to homeostasis

Positive Feedback System
Strengthens or reinforces a change in one of the body’s controlled conditions Ex) Birth.
Goes further away from homeostasis
Anatomical Position: the subject stands erect facing the observer with the head level, eyes forward, feet flat directed forward, palms forward.
Directional Terms:
Superior-above, top, towards head
Inferior- below, bottom, away from head
Anterior (Ventral)-toward the front
Posterior (Dorsal)- toward the back
Medial-toward the midline(vertical)
Lateral-away from the midline
Intermediate-between medial and lateral
Proximal-nearest to the origin of a limb Ex) humerus
Distal-further from the origin of a limb Ex) Fingers
Ipsilateral- Same side of the body
Contralateral- Opposite sides of the body
Superficial-towards the surface
Deep-towards the core of the body
Visceral-covering over an organ
Parietal-covering a cavity wall
Anatomical Terminology-KNOW IT ALL!!!!!

Body Planes
Separate the body into portions
Sagittal-straight through the middle of the head. Left and right halves
Transverse- separates top and bottom
Frontal- separates front and back
Oblique- not at a 90 degree angle

Body Cavities****
See figure 1.6 and 1.11!
The Cell
Eukaryotic Cell:
Cytoplasm-a gelatin like substance, plus structural fibres and organelles, contains all the cellular contents between the plasma membrane and the nucleus, cytosol(fluid portion) organelles embedded in cytosol.
Nucleus- contains the genetic library of the cell,
Plasma Membrane-
Cytoskeleton-Types> microfilaments(actin=muscles), intermediate filaments(structure), microtubules(cilia and flagella).
Cilia-short hair like projections and made of microtubules that emerge from the cell surface. Typically used to move fluids along a surface.
Flagella-longer than cilia, can move the entire cell, used for swimming (sperm cell tail)