Exp 8 Bones

Ex 8: Bone Classification, Structure & Relationships: An Overview

This lab is designed to provide students with an overview of bones through a variety of investigative activities.
https://sites.google.com/site/physiolablist/
The Objectives for this lab are:

1. To list at least three functions of the skeletal system.
2. To identify the four main kinds of bones.
3. To identify surface bone markings and their function.
4. To identify the major anatomical areas on a longitudinally cut long bone (or diagram of one).
5. To identify the major regions and structures of an osteon in a histological specimen of compact bone (or diagram or model of one).
6. To explain the role of the inorganic slats and organic matrix in providing flexibility and hardness to bone.

Hypotheses & Procedures
Part 1: Bone Markings & Classification.
     If students examine a variety of disarticulated bones then they will be able to classify them into one of the four anatomical groups: long, short, flat, or irregular and point out examples of bone markings.

Part 2: Gross Anatomy of the Typical Long Bone.
      If students examine a fresh cut bone as well as a cleaned dry bone that has been cut along its longitudinal axis, then they will be able to identify the major anatomical structures of a bone as an organ.


Part 3 Microscopic Structure of Compact Bone.
     If students observe a prepared slide of ground bone as well as a model of microscopic compact bone, then they will be able to identify the major regions and structures of an osteon.


Part 4: Chemical Composition of Bone:
     If students observe a sample of bone that has been baked then they will be able to identify the role of the organic compounds in bone because baking removes the collagen fibers of the matrix.
     If students observe a sample of bone that has been soaked in acid then they will be able to identify the role of the inorganic compounds in bone because acids dissolve the calcium salts.



Materials (on lab sheet)


Experiment/Data and lab questions

Part 1: Bone Markings & Classification.  

     Insert a picture of each type of bone, with a caption identifying its shape as long, short, flat, or irregular.  Within your caption, also identify any bone markings that show up in your picture.

Long bone, Medullary cavity

Two long bones and the flat bones of the skull.  PIRATE STYLE. 

Irregular pelvis, flat breastbone, irregular little thin wingy bone thing in the back right

Irregular pelvis

Part 2: Gross Anatomy of the Typical Long Bone. 

      Insert at least one picture your partner pointing out a specific feature of long bone. Provide a caption to identify the specific feature.

Part 3 Microscopic Structure of Compact Bone. 

     Copy/paste this image into a draw program (like MS Paint).  Label the parts of the osteon that you can identify.  Save the image and use it to replace the unlabeled one into your blog, .

Part 4: Chemical Composition of Bone: 

Do treated bones retain the structure of untreated specimens?
 No they don't, as the ones that were soaked in vinegar no longer have the hard bone intact.  The baked bones do have the surrounding hard bone, but the soft marrow and living material is gone.

    

Describe what happened to the matrix when the bone was baked.  How does this bone feel?
The matrix  remained  after the living matter was killed by the heat, and the matrix is left feeling hard and brittle.

Describe what happened to the matrix when the bone was soaked in acid.  How does this bone feel?
The matrix dissolved as the acid reacted with the calcium that made up the matrix, and the living matter is ll that is left.  It feels soft and slimy.


Optional: Include a video of your lab team demonstrating the effects of baking and acid on the matrix of bone.

Conclusion:

1.  List at least three functions of the skeletal system.
1. Support, protection, movement, storage, blood cell formation
2. Identify the four main kinds of bones.
1. Long, short, flat, irregular
3. Which surface bone markings and their function can you identify and describe?
1. Tuberosity--on the femur, at the end, round projection
4. Which major anatomical areas on a longitudinally cut long bone (or diagram of one) can you identify?
1. Periosteum, compact bone, medullary cavity, spongy bone
5. Which major regions and structures of an osteon in a histological specimen of compact bone (or diagram or model of one) can you identify?
1. Lacunae, osteocytes, canaliculi, haversian canal, lamellae
6. Explain the role of the inorganic slats and organic matrix in providing flexibility and hardness to bone.
1.  

Ex7: The Skin and Other Body Membranes

Ex7: The Skin & Other Body Membranes

I. Introduction/Background Information

Refer to the Lab worksheet : https://sites.google.com/site/physiolablist/

There are several sections to this lab, generally designed to assist students in understanding the structures & functions of skin & other body membranes. The objectives of this lab are:

1. to recount important functions of the skin/integumentary system
2. to recognize and name the following structures from a slide, model or diagram
• epidermis (including strata),
• dermis (papillary & reticular layers
• hair follicles & hair
• sebaceous glands & sweat glands
3. to compare the properties of the dermis & epidermis
4. to describe the distribution and function of the sebaceous glands, sweat glands, and hair
5. to differentiate between eccrine & apocrine sweat glands
6. to ennumerate the factors determining skin color
7. to describe the function of melanin
8. to compare the structure and function of the major membrane types
9. to list the general functions of each membrane type and note its location in the body
10. to recognize by microscopic examination epidermal, mucous, and serous membranes

II. Hypothesis

Part 1: Basic structure of the skin: If students read about structures as they locate them on a skin model then they will be able to write out a response to each objective
Part 2: Appendages of the Skin: If students examine a prepared slide of human skin then they will be able to identify skin structures on a drawing.
Part 3: Plotting the Distribution of sweat glands: If bond paper is taped to skin coated with iodine and left for 20 minutes, then a distribution of sweat glands will be mapped out because the sweat glands will dissolve the iodine, which will then be absorbed by the paper. As it reacts with the starch in the bond paper each sweat gland will produce a blue/black dot.
Part 4: Classification of Membranes: If students examine slides from trachea and small intestine, heart, as well as a freshly cut joint, then they can compare mucous, serous and synovial membranes.

III. Materials

Model of Skin, prepared slides/pictures, iodine, 1cm x 1 cm bond paper squares, tape.

IV. Procedure

“See Lab Instructions” (you may include pictures of procedure)

Part 1: Basic structure of the skin: Compare the following structures identified in the pictures with the model in the classroom.

Skin slide

Human Skin Slide

Part 2: Appendages of the Skin:
Part 3: Plotting the Distribution of sweat glands: Insert a photo of each of your sweat distribution patches. Label them "palm" and "forearm".
Part 4: Classification of Membranes:

pseudostratified ciliated columnar epithelium

mucosa of trachea

mucosa of small intestine

drawing of one villus

pericardium (around the heart)

V. Results/Observation/Data
List answers to questions from each section of the lab

Part 1: Basic structure of the skin: (No questions in this section)
Part 2: Appendages of the Skin:
What additional features did you observe in the two photos of skin (above) that you didn't see in the slides of stratified squamous epithelium that you studied for Chapter 3?
We did not observe Meissner's Corpuscle and the sebaceous glands.
Part 3: Plotting the Distribution of sweat glands:
Which skin area tested had a greater density of sweat glands?
The palm had a greater density of sweat glands.
Labeled Pictures:

palm sweat glands


forearm sweat glands

Part 4: Classification of Membranes:
How do the roles of trachea mucosa and small intestine mucosa differ? How are they the same?
The trachea mucosa secrete mucous and move it up using cilia while small intestine mucosa absorb nutrients using villi.

Do you think that mucous membranes have a high regenerative capacity? Explain why or why not.
Yes, mucous membranes are subject to severe abrasion and wear and tear, thus it must be able to regenerate at a sufficient rate to replace lost cells.



The pericardium is an example of a serous membrane. It's too tiny to see, but the endothelium is composed of simple squamous epithelium. List the specific names of the following serous membranes:
covering of the heart: visceral pericardium
Lining of the cavity in which the heart resides: visceral pericardium
Covering of the lungs: visceral pleura
Lining of the thoracic cavity: parietal pleura
Covering on the viscera: visceral peritoneum
Lining of the visceral cavity: parietal peritoneum

VI. Conclusion: Respond to each objective. What did you learn?

1. What are the important functions of the skin/integumentary system? The functions of the skin are to protect the body from the environment, from both abrasion as well as bacterium. The integumentary system is also involved in secreting waste in the form of sweat, which also cools the body.
2. Can you recognize and name the following structures from a slide, model or diagram?
• epidermis (including strata), yes
  
• dermis (papillary & reticular layers, yes
  
• hair follicles & hair, yes
  
• sebaceous glands & sweat glands, yes
  
3. Compare the properties of the dermis & epidermis: The dermis contains blood as well as nerve endings, whereas the epidermis is composed of stratified squamous epithelium and keratin.
   
4. Describe the distribution and function of the sebaceous glands, sweat glands, and hair Sebaceous glands are are concentrated around the hair follicle, they are responsible for oil secretion. Sweat glands secrete sweat and are distributed around the skin; they are independent of the hair follicle. Also, their concentration varies around the body. Hair shafts are present all over the skin except in the palms and the soles of the feet. Evolution-wise, hair was meant to provide warmth; however, our hair on our skin has become too thin to provide warmth.
   
5. Differentiate between eccrine & apocrine sweat glands. Eccrine glands are on the palms, soles, and forehead, and virtually on all skin. Apocrine glands are in the axillae and genital areas.
6. Ennumerate the factors determining skin color. Skin color depends on, firstly, genetics. Genes determine how dark your skin is. However, light exposure also plays a role in skin color. The more the skin is exposed to light, the darker the skin becomes.
7. Describe the function of melanin. Melanin is a pigment that filters the ultra-violent radiation from the sun, protecting the tissues and organs underneath the skin.
8. Compare the structure and function of the major membrane types AND
9. List the general functions of each membrane type and note its location in the body: Membranes cover body surfaces, line cavities and protect organs. The mucous membrane is epithelial tissue that is open to the exterior environment (such as the lungs and trachea). Its function is secretion and absorption. Serous membranes is also epithelial tissue that lines closed organs (such as the heart). Its function is lubrication. Cutaneous membrane is epithelial tissue that forms the outer layer of the skin, protecting the tissues and organs underneath. Synovial membranes are connective tissue that provide a frictionless surface to movable joints.
10. Can you recognize by microscopic examination epidermal, mucous, and serous membranes? It is more likely for us, at this point, to be able to recognize epidermal membranes with its stratified squamous epithelium cells, than mucous and serous membranes. Mucous and serous membranes are harder to identify because we have not seen many slides.