LAB PROJECT - HUMAN LIMB

First of all, this model did not come out as elaborate as I would have liked. Anyway, I attempted a model of the human arm. The parts you see are the ball joint, bicep, tricep, tendons, hinge joint and the bone. The humerus is the bone attached to the ball joint here in this picture. The ulna and radius would make up the bottom two bones, shown as one in picture, and attached by a hinge joint at the elbow. The bicep and the tricep are the two muscles which help in arm movement.

In this picture, it shows the myosin, actin, and cross bridge. The whole picture is a representation of a sarcomere. It is at its relaxed state here.

In this picture are all the same components from above, but the sarcomere is shown in contracted state, which is what happens in a muscle.

In this picture is one myofibril, it is showed with the sarcolemma covering, which would be around the unit as a whole. It also represents T tubule and sarcoplasmic reticulum, which stores the calcium.

In this picture, and I don't know why it turned sideways, is the start of the function of Ca2+.

In this picture it shows Ca2+ binding to troponin, and also exposes mysosin binding sites.

Here is a picture of an action potential with axon covered by myelin sheath.

To sum everything up a little, when muscles are stimulated impulses travel down a T tubule and calcium is released by the sarcoplasmic reticulum. Muscle fiber contracts as the sarcomere shortens. Actin filaments slide past myosin. The movement of actin filaments in relation to myosin filaments is called the sliding filament model of muscle contraction. The myosin, however, is the one that does all the work. Myosin breaks down ATP, and their cross bridges pull in actin filaments toward center of the sarcomere.

Hopefully this all makes a little sense to you and I hope the pictures explained a lot. It is amazing the details are muscles go through just to move. It brings to mind the muscles in my wrists right now, and how they endure one position for so long. Our bodies are just amazing.

LEECH NEURONS LAB

Here is this picture of the manipulator with oscillope trace.

Here is the neuron with dye under ultraviolet light. Look closely and you can see the shape of a sensory neuron.

Here in this illustration is the neuron being probed by a feather, a probe, and forceps to see any reaction. The neuron tested here is identified as a P cell.

1. Electrode measuring is a way to record the activities of neurons.

2. Leeches were used because they have simpler systems, that are easier to understand and they have a simple nervous system. Which obeys many of the same rules as a complex system like ours.

3. The difference between a sensory and motor neuron is: sensory takes nerve impulses from sensory receptor to the CNS. Motor takes nerve impulses away from the CNS to an effector.

4. Yes, doesn't anything with nerves experience it? Pain is a sensory experience that describes an unpleasant awareness of a noxious(harmful) stimulus or bodily harm.

5. The 2 most interesting things. Well it was hard to pick 2. Dissecting the leech was interesting and probing cells and testing them.

6. No, I didn't find anything confusing about this lab or anything I didn't like.

COMPENDIUM REVIEW #2 FOR UNIT #3

TABLE OF CONTENTS


CHAPTER 11- SKELETAL
1. Overview of the skeletal system
a. Functions
b. Anatomy of a long bone
2. Bone growth, remodeling and repair
a. Bone development and growth
b. Bone remodeling and its role in homeostasis
c. Bone repair
3. Bones of Axial Skeleton
a. Skull
b. Hyoid
c. Rib cage
4. Bones of Appendicular Skeleton
a. Pectoral girdle and upper limb
b. Pectoral girdle and lower limb
5. Articulations
a. Movements

CHAPTER 12 - MUSCULAR SYSTEM

6. Overview of Muscular System
a. Types
b. Functions
c. Skeletal
d. Names and actions
7. Skeletal Muscle and Fiber Contractions
a. Muscle fibers
b. Control of muscle fiber
8. Whole Muscle Contraction
a. Muscles have motor units
b. Energy for contraction
c. Fast twitch and slow twitch muscle fibers
d. Delayed onset soreness
9. Muscle disorders
a. Common conditions
b. Muscular diseases
10. Homeostasis
a. Protect
b. Store and release

CHAPTER 11 - SKELETAL SYSTEM


OVERVIEW OF SKELETAL SYSTEM
The skeleton supports the body, protects soft body parts, produces blood cells, stores minerals
and fat and along with muscles, permits flexible body movement.

In the anatomy of a long bone, the hyaline cartilage covers the ends of the bone. The periosteum covers the rest of the bone. Spongy bone in in the epiphyses. Yellow bone marrow is in the medullary cavity of the diaphysis and compact bone makes up the wall of the diaphysis.
See illustration.*

BONE GROWTH, REMODELING, AND REPAIR

Cells involved in growth, remodeling and repair of bone are: osteoblasts, which are bone forming cells, osteocytes, which are mature bone cells derived from osteoblasts and osteoclasts, which break down and absorb bone.

For bone growth, intramembranous ossification is when bones develop between sheets of fibrous connective tissue. For example, flat bones such as bones of the skull.

Endochondral ossification: cartilaginous models of the bones are replaced by calcified bone matrix. See illustration.*

Bone growth is affected by vitamin D, growth hormone, and sex hormones.

Bone remodeling is the renewal of bone. Osteoclasts break down bone and osteoblasts re-form bone. Some bone is recycled each year. Bone recycling allows the body to regulate blood calcium.

Repair of a fracture requires 4 steps: hematoma formation, fibrocrtilaginous callus, bony callus and remodeling.

BONES OF THE AXIAL SKELETON
The axial skeleton consists of the skull, the hyoid bone, the vetebral column and the rib cage.
The skull is formed by the cranium, which protects the brain and the facial bones. The cranium's major bones are: frontal bone, parietal bones, occipital bone, and the temporal bones.

The hyoid bone anchors the tongue and is the site of attachment of muscles involved with swallowing. The vetebral column is composed of vertebrae separated by shock-absorbing disks, which make the column flexible. It supports the head and trunk, protects the spinal cord, and is a site for muscle attachment. The rib cage is composed of the thoracic vertabrae, ribs, costal cartilages, and sternum. It protects the heart and lungs.

BONES OF THE APPENDICULAR SKELETON

The appendicular skeleton consists of the bones of the pectoral girdles, upper limbs, pelvic girdle and lower limbs.

The pectoral girdles and uppper limbs are adapted for flexibility.
The pelvic girdle and the lower limbs are adapted for supporting weight: the femur is the longest and strongest bone in the body.

Here is an illustration of all 206 bones in our bodies.*

ARTICULATIONS

Bones are joined at joints. There are 3 types of joints.

1. Fibrous joints ( such as the sutures of the cranium) are immovable.
2. Cartilaginous joints ( such as those between the ribs and sternum and the pubic symphysis) are slightly movable.

3. Synovial joints ( which have a synovial membrane) are freely movable. See illustration.*

CHAPTER 12 - MUSCULAR SYSTEM

OVERVIEW OF MUSCULAR SYSTEM

There are 3 types of muscle tissue. 1. Smooth muscle is involuntary and occurs in walls of internal organs. 2. Cardiac muscle is involuntary and occurs in walls of the heart. 3. Skeletal muscle voluntary, contains bundles of muscle fibers called fascicles, and is usually attached by tendons to the skeleton. The functions of skeletal muscles are: help maintain posture, provide movement and heat, and protect underlying organs. See illustration.*

Muscles are named for their size, shape, location, direction of fibers, number of attachments, and action. When achieving movement, some muscles are prime movers, some are synergists, and others are antagonists.

SKELETAL MUSCLE FIBER CONTRACTION

Muscle fibers contain myofibrils. Myofibrils contain actin and myosin filaments. Muscle contraction occurs when sarcomeres shorten and actin filaments slide past myosin filaments.
See illustration.*

- nerve impulses travel down motor neurons and stimulate muscle fibers at neuromuscular junctions.

- the sarcolemma of a muscle fiber forms T tubules that almost touch the sarcoplasmic reticulum, which stores CA ions.

- when CA ions are released into muscle fibers, actin filaments slide past myosin filaments.

- at a neuromuscular junction, synaptic vesicles release acetylcholine, which diffuses across the synaptic cleft.

- acetylcholine(Ach) is received by the sarcolemma, impulses begin and lead to the release of CA.

- CA ions bind to troponin, exposing myosin binding sites.

- myosin filaments break down ATP and attach to actin filaments, forming cross-bridges.

- when ADP and P are released, cross-bridges change their positions.

- this pulls actin filaments to the center of a sarcomere.

WHOLE MUSCLE CONTRATION
Muscles have motor units: several fibers under the control of a single motor axon. Motor unit contraction is described in terms of a muscle twitch, summation and tetanus. The strength of muscle contraction varies according to recruitment of motor units.

In the body, a continuous slight tension is maintained by muscle motor units that take turns contracting.
For energy, a muscle fiber has 3 ways to acquire ATP for muscle contraction.

1. Creatine phosphate transfers a phosphate to ADP, and ATP results. This CP pathway is the most rapid.

2. Fermentation also produces ATP quickly. Fermentation is associated with an oxygen debt because oxygen is needed to metabolize the lactate that accumulates.

3. Cellular respiration provides most of the muscle's ATP, but takes longer because much of the glucose and oxygen must be transported in blood to mitochondria. Cellular respiration occurs during aerobic exercise and burns fatty acids in addition to glucose.

Fast twitch muscle fibers are for sports like weight training. These rely on anaerobic means of acquiring ATP. Have few mitochondria and myoglobin, but motor units contain more muscle fibers and are known for explosive power, but fatigue quickly.

Slow twitch muscle fibers are for sports like running or swimming. These rely on aerobic respiration to acquire ATP. Have a plentiful supply of mitochondria and myoglobin, which gives them dark color. See illustration.*

MUSCULAR DISORDERS

Muscular disorders include spasms and injuries, as well as diseases such as muscular dystrophy and myasthenia gravis.

HOMEOSTATSIS

The muscles and bones produce movement and protect body parts, the bones produce red blood cells and are involved in the regulation of blood calcium levels. The muscles also produce the heat that gives us a constant body temperature. In this illustration it shows are the skeletal and muscular systems interact with other body systems.*

*http://highered.mcgraw-hill.com/classware/selfstudy.do?isbn=0072986867

COMPENDIUM REVIEW # 1 FOR UNIT # 3

TABLE OF CONTENTS
CHAPTER 13

NERVOUS SYSTEM

1. Overview of the Nervous System
a. Nervous tissue
b. Neuron structure
c. Myelin sheath
d. Propagation of an action potential
f. Synapse
2. Central Nervous System
a. Spinal cord
b. The brain
3. Limbic System and Higher Mental Functions
a. Limbic system
b. Higher mental funtions
4. The Peripheral Nervous System
a. Somatic system
b. Autonomic system
c. Somatic versus the autonomic system
5. Drug Abuse
a. Alcohol
b. Nicotine
c. Cocaine
d. Methamphetamine
e. Heroin
f. Marijuana
CHAPTER 14
SENSES
6. Sensory Receptors and Sensations
a. Types of sensory receptors
b. How sensations occurs
7. Proprioceprors and Cutaneous Receptors
a. Proprioceptors
b. Cutaneous receptors
c. pain receptors
8. Senses of Taste and Smell
a. Sense of taste
b. Sense of smell
9. Sense of Vision
a. Anatomy and physiology of the eye
b. Abnormalities of the eye
10. Sense of Hearing
a. Anatomy and physiology of the ear
11. Sense of Equilbrium
a. Rotational equilibrium pathway
b. Gravitational equilibrium pathway


CHAPTER 13

OVERVIEW OF THE NERVOUS SYSTEM

The nervous system is divided into the central nervous system(CNS) and the peripheral nervous system(PNS). It has 3 functions: 1. reception and input, 2. integration of data, 3. generates motor input.
Nervous tissue contains 2 types of cells: neurons and neuroglia. Neurons transmit nerve impulses and Neuroglia nourish and support neurons.

A neuron is composed of dendrites, a cell body and an axon. There are 3 types of neurons: 1. Sensory neurons which take nerve impulses form sensory receptors to the CNS. 2. Interneurons occur within the CNS and 3. Motor neurons take nerve impulses from the CNS to effectors.

See illustration.*

The myelin sheath is the covering over long axons.

Nerve impulse includes resting potential and action potential. Resting potential is more sodium ions (Na+) outside the axon and more potassium (K+) inside the axon. The axon does not conduct and impulse.

Action potential is a change in polarity across the axonal membrane as a nerve impulse occurs: when Na+ gates open, Na+ moves to the inside of the axon, and depolarization occurs. When K+ gates open and K+ moves to outside the axon, a repolarization occurs. See illustration.*

A synapse is junction between neurons consisting of the presynaptic (axon) membrane, the synaptic cleft, and postsynaptic (usually dendrite) membrane.

When a neurotransmitter is released into a synaptic cleft, transmission of a nerve impulse occurs.

Neurotransmitter binds to receptors in receiving membrane and causes excitation or inhibition.

Integration is the summing of excitatory and inhibitory signals.

See illustration.*

THE CENTRAL NERVOUS SYSTEM

The CNS receives and integrates sensory input and formulates motor output. The CNS consists of the spinal cord and brain.
The spinal cord is the nerve cord that is continuous with the base of the brain plus the vertebral column that protects the nerve cord.
A cross section of the spinal cord shows a central canal, gray matter and white matter. Gray matter contains neuron cell bodies. White matter consists of myelinated axons that occur in tracts.

It conducts to and from the brain and carries out reflex actions.

The brain has 4 major parts, the cerebrum, the diencephalon, the cerebellum and the brain stem. It also has 4 ventricles, 2 lateral ventricals, the 3rd ventrical and the 4th ventrical.

See illustration.*

The cerebrum has two cerebral hemispheres connected by the corpus callosum. Sensation, reasoning, learning and memory, and language and speech take place in the cerebrum. the cerebral cortex covers the cerebrum. The cerebral cortex of each cerebral hemisphere has four lobes: frontal, parietal, occipital, and temporal.

The frontal lobe sends out motor commands to lower brain centers, which pass them on to motor neurons. The parietal lobe receives sensory information from lower brain centers in communication with sensory neurons. Association areas are located in all lobes.

See illustration.*

The Diencephalon includes the hypothalmus which controls homeostasis. the thalamus sends sensory input on to the cerebrum.

The cerebellum coordinates skeletal muscle contractions.

The brain stem, the medulla oblongata and the pons have centers for breathing and the heartbeat.

THE LIMBIC SYSTEM AND HIGHER MENTAL FUNCTIONS

The limbic system, which lies deep in the brain, is involved in determining emotions.
The amygdala determines when a situation deserves the emotion we call "fear."
The hippocampus is particularly involved in storing and retrieving memories.

THE PERIPHERAL NERVOUS SYSTEM

The PNS only contains only nerves and ganglia. Cranial nerves take impulses to and from the brain. Spinal nerves take impulses to and from the spinal cord. The PNS is divided into the somatic systema and autonomic system.

The somatic system serves the skin, skeletal muscles, and tendons. Some actions are due to reflexes, which are automatic and involuntary. Other actions are voluntary, and originate in the cerebral cortex.
The autonomic system is divided into 2 divisions which are sympathetic division and the parasympathetic division. The Sympathetic Division are responses that occur during times of stress. The Parasympathetic Division are responses that occur during times of relaxation. The actions in these divisions are involuntary and automatic. These divisions also innervate internal organs. There are two neurons and one ganglion are utilized for each impulse.

See illustration.*

DRUG ABUSE

Drugs that are commonly abused include alcohol, nicotine, cocaine, methamphetamine, heroin and marijuana.
The effects of alcohol and heroin on the CNS is a depressant. Nicotine, cocaine, and methamphetamine all acts as a stimulant. Marijuana acts as a psychoactive, it creates a euphoria.

CHAPTER 14

SENSES

SENSORY RECEPTORS AND SENSATIONS

There are 4 types of sensory receptors: chemoreceptors ( taste and smell), photoreceptors (vision), mechanoreceptors ( hearing, rotational and gravitational equilibrium) , and thermoreceptors(located in hypothalamus and skin).

Sensory receptors initiate nerve impulses that are transmitted to the spinal cord and/or brain.

Sensation occurs when nerve impulses reach the cerebral cortex. Perception is an interpretation of sensations.

See illustration.*

PROPRIOCEPTORS AND CUTANEOUS RECEPTORS

Proprioceptors are mechanoreceptors involved in reflex actions and help maintain equilibrium and posture.

Cutaneous receptors are found in the skin and are for touch, pressure, temperature, and pain.

SENSES OF TASTE AND SMELL

Taste and smell are chemoreceptors. They are stimulated by molecules in the environment.

Sense of taste: Microvilli of taste cells have receptor proteins for molecules that cause the brain to distinguish sweet, sour, salty, and bitter tastes.

Sense of smell: The cilia of olfactory cells have receptor proteins for molecules that cause the brain to distinguish odors.

SENSE OF VISION

Vision depends on the eye, the optic nerve, and the visual areas of the cerebral cortex.

The eye has 3 layers. The sclera ( outer layer), the choroid ( middle layer), and the retina ( inner layer).

See illustration for the in depth anatomy of the eye.*

In this illustration it gives the parts of the eye and what it does.*

The lens of the eye brings the light rays to focus on the retina. To see a close object, visual accommodation occurs as the lens rounds up.
The visual pathway to the brain begins when light strikes photorecptors in the retina. The optic nerves carry nerve impulses from the eyes to the optic chiasma, then pass through the thalamus before reaching the primary vision area in the occipital lobe of the brain.

Some abnormalities of the eye are color blindness and a misshapen eyeball.

SENSE OF HEARING

Hearing depends on the ear, the cochlear nerve and the auditory areas of the cerebral cortex.

This illustration gives all the parts of the ear.*

The ear has 3 parts. In the outer ear, the pinna and the auditory canal direct sound waves to the middle ear. In the middle ear, the tympanic membrane and ossicles amplify sound waves. In the inner ear, the semicircular canals detect rotational equilibrium; the utricle and saccule detect gravitational equilibrium; and the cochlea houses the spiral organ, which contains mechanoreceptors for hearing.

Auditory pathway to the brain begins when the outer ear receives and the middle ear amplifies sound waves that then strike the oval window membrane.

The mechanoreceptors for hearing are hair cells on the basilar membrane of the spiral organ. Nerve impulses begin in the cochlear nerve and are carried to the primary auditory area in the temporal lobe of the cerebral cortex.

SENSE OF EQUILIBRIUM

The ear also contains mechanoreceptors for equilibrium.

Rotational equilibrium pathway is when the hair cells in the semicircular canals detect rotational and/or angular movement of the head.

Gravitational equilibrium Pathway is when the hair cells in the utricle and saccule detect head movement in the vertical or horizontal planes.

*http://highered.mcgraw-hill.com/classware/selfstudy.do?isbn=0072986867