Human Anatomy ll

Lesson Structure:

There are 7 lessons:

Cytology
Surface Anatomy
Systemic Anatomy I
Systemic Anatomy II
Regional Anatomy I
Regional Anatomy II
Radiographic and Diagnostic Anatomy

Each lesson culminates in an assignment which is submitted to the school, marked by the school's tutors and returned to you with any relevant suggestions, comments, and if necessary, extra reading.

Practicals:

Describe the importance of the following structures of the eye: eyelids, eyelashes, and eyebrows.
What structures form the oral cavity? Briefly describe their importance.
Using the internet or other reference material, outline and describe otitis media and its causes.
Besides the eyes, ear, and mouth ... what other structures can be studied without a microscope ? List at least ten.
Using the internet or other reference material, describe the three basic functions of the nervous system that are necessary to maintain homeostasis.
Using reference materials or the internet, distinguish between grey and white matter and describe where they are found and their differences.
Using the internet or other reference material define the following: resting membrane potential, depolarization, repolarization, polarized membrane, nerve impulse, depolarized membrane, repolarized membrane, and refractory period.
List and describe the structure of the four principle parts of the brain.
Compare and contrast neurons and neuroglia, describing both structure and function
List the names and locations of the principal body cavities and their major organs.
List the names and locations of the abdominopelvic quadrants and regions.
In which quadrant would you feel the pain from appendicitis? From an inflamed liver or gallbladder problems? Problems with the sigmoid colon? Problems with the spleen?
Using the internet or other reference materials find a sample image of the listed medical imaging techniques.

The study of the human body can be divided into specific fields, one of which is anatomy. Anatomy is the study of structure, how parts of the body are sized and shaped and how they interact with each other, as well as the tissues that form them. It does not consider how parts of the body function; what they do, this is the field of physiology.

Anatomy is and was the starting point of scientific investigation of the human body. Without an understanding of structure we cannot fully understand function, for it is the structure and interrelation of body parts that permits their function. In order to study anatomy, it is important to understand the different medical/scientific terms that are used to indicate location, relationship, components, numbers and so on. Key terms are introduced early in the course, some of which you may be familiar. These should still be reviewed along with new terms, to ensure you are able to fully understand this course.

Why Study This?

Anatomy may be valuable, if not critical in many jobs, for example:

Medical, Health and Fitness Support jobs (Receptionists and assistants)
Fitness instructors, sports coaches, personal trainers
Massage therapists and other complimentary medicine practiytioners
Retail staff in health food shops, pharmacies, sports stores, even footware stores
Writers and Journalists
Medics, Doctors, Researchers, Academics, Lecturers etc.




How Do Cells Divide? (extract from course notes)

The cell cycle is broken up into two stages – interphase and mitosis. Interphase is further divided into the following phases (we will list them in order following mitosis):

• G1
Gap 1. This is a period where the new daughter cell increases its metabolic activity after cell division has finished. The cell is producing proteins that are needed to allow it to perform its function.

• S phase
Synthesis (DNA) phase. This is the period when the cell’s genome is replicated.

• G2
Gap 2. Another period of high metabolic activity. However, compared to G1, the cell is now producing the proteins it will need for the upcoming mitosis.

Mitosis can be broken down into 6 phases which we will discuss further later in the lesson.

Characteristic Interphase Structures
DNA structure varies throughout the cell cycle. In interphase, many genes are being transcribed. This requires them to be in a loose, open structure, so regulatory proteins can bind to them. This structure is known as euchromatin, the DNA is loosely wound around the histones. Genes that are not being transcribed are found in regions of heterochromatin. Heterochromatin is a closed, tight DNA structure, where the DNA is wrapped tightly around histones.

During S phase, the entire genome is copied, resulting in chromosomes made up of two identical ‘sister’ chromatids. During replication of DNA, a replication fork forms. An enzyme known as helicase (the suffix – ase indicates something is being broken or broken down) breaks the bonds that hold the two strands of DNA together in the double helix conformation. The point where the separation is the replication fork, where the original double helix has branched into two single strands that are then replicated to form their own new double helices.

Characteristic Mitosis Structures
As cells enter M phase, or mitosis they have gone from having single chromatids to chromosomes made up of two chromatids bound together. We will look at each phase of mitosis individually, in the order they occur in the cell:

Prophase
Chromatin is condensed into chromosomes. These are clearly visible under a microscope. The point where the chromatids are joined is the centromere. The distal ends of each chromatid are the telomeres. The centrosome is replicated during S phase and so two are present in prophase, adjacent to the nucleus and in relatively close proximity to each other. These each start to build microtubules and each centriole begins to be pushed away from the other.

Prometaphase
The centrosomes are on opposite sides of the nucleus with the microtubules they have produced spanning between them and creating the mitotic spindle. The centrosomes are said to be at opposite ‘poles’ of the cell. In this phase, the nuclear envelope breaks down, so the microtubules run through what used to be the nucleus. Protein ring structures known as kinetochores are formed at the centromeres of each chromosome. One attached to each chromatid. The microtubules attach to the chromatids via these kinetochores.

(Note: You will sometimes see Prophase and Prometaphase combined and referred to as Prophase, they are not always viewed as separate/distinct phases)


Metaphase
The chromosomes line up vertically along the central axis of the cell, intermediate to the poles of the cell. This is known as the metaphase plate. The lining up of the chromosomes is a feature that allows scientists to distinguish cells that are in metaphase from those in other stages of the cell cycle, using a microscope.

Anaphase
In this phase the bonds between sister chromatids are broken. The sister chromatids are then pulled by to the opposite poles of the cell as its attached microtubule shortens. The centrioles are pushed further apart, right to the poles of the cell, dragging the chromatids, which are attached via the microtubules, with them. This results in two identical sets of DNA/centrosomes separated from each other on opposite sides of the cell.

Telophase
The cell becomes elongated as the centrosomes continue to be pulled to the poles of the cell. This gives the cell a slightly oval shape. In this phase the nuclear envelope begins to reassemble, one around each set of DNA. Chromatids decondense so that the cell now has two nuclei, full of chromatin.

Cytokinesis
Cytokinesis occurs with telophase. As the nuclear envelopes are forming and the DNA decondensing the cell begins to pinch in along the short axis of the cell. This pinching forms a depression, known as the cleavage furrow. This furrow continues to deepen; pinching the cell until it completely separates into two identical daughter cells, with one nucleus each.
Using the anatomical features of cells, it is possible to distinguish cells in different phases, by microscopy at high magnification. This is important in scientific research investigating events occurring at very specific times during the cell cycle.