The Skeletal System

I learned in the skeletal system that the bone cells osteocytes  maintain matrix within the lucunae.Osteoblasts deposit matrix , and when they get caught  become osteocytes. Osteoblasts come from osteochondral progenitor cells  , which comes from mesenchymal cells  all cells resposible for making connective tissue. Osteoclasts break down nbone , secrete water , make hydrochloric acid , breaks down collagen fibers . Precursor cells are monocytes ,which phagocyte , andand become become" big eaters" nacrophages. Cells that produce cartilage are chondoblasts ,and are trapped inside and become chondrocytes .The job of the chondrocytes is to maintain cartilage . In the bone matrix the inorganic material consists primarily of hydroxyapatite . The organic molecules has two things C02 ,and H2 .Collagen is a lipid , a big molecule, subunit protein anino acid is 20.Collagen -amino acids are all organic.The function of the skeletal system is to support , to hold the body up ,prtection of all major organs , movement , and storage . I learned there are two types of cartilage ; hyaline  , and fibrocartilage . Fibrocartililage is found in the intervebral discs ,sympyhsis ,balland socket / glenoid cavity . The hyaline cartilage can be found in in the synovial joints , slick surfaces , epephyses paltes , long bones ,synchondroses ,bends ,ribs to sternum . We grow cartilage byinterstitial and appositional growth .Interstitial , catilage replicates, , appositional  , chondroblasts add new cartilage to the outside of the cartilage .I learned the two tyoes of bone growth , intramembranous ossification , and endochondral ossification . Intramembranous growth takes palce within the connnective tissue membrane , while the endochondral ossification takes palcein the cartialage .Both methods produce woven bone , which is then remodeled .

Tisssues and Muscles

I've learned in lab regarding the tissues that the simple squamous epithelium is located in the kidney glomeruli , it's job is to line , cover , filter , and produce serous fluid. It .lines the mesothelium cavity that encloses the organs such as the heart , abdomen and lung . The  simple cuboidal epithelium is located in the kidney tubules , it's function is secretion and absorption. The simple columnar epithelium lines the intestines , job is secretion and absorption . The pseudostratified columnar epithelium moves stuff out of trachea , secretes particularly mucous .The transitional epithelium  tissue is ballooned shaped ,streches to accomadate storage of urine . It lines the ureters , urinary bladder,and part of the urethra .The loose areolar connective tissue consists of looose collection of cells with lots of space .This tissue anchors dermis , epidermis papillary layer .The hyaline cartilage covers the end of long bones ,chronoblasts produce the matrix and when mature chrondrocytes lie in the lucunae .Elastic cartilage supprts the external ear , maintaining the structure while allowing flexibility .The fibrocartilage is located between the interverbral discs , cushions between bones .The compact bone supports , and protects , the osteocytes lie in the lucunae. The pacinian corpuscles lie in the hypodemis ,it's function is deep cutaneous pressure , and vibration. Arranged like leaves of an onion .The integumentary is the skin which has several layers , including the luciden . The scalp  which consists of the hair follicles , with the arrector pili muscle, sebacous glands and sweat glands . The multipolar cell , the nervous tissue consists of motor neurons ,glia cells and other large cells .The retina consisted of the fibrous coat ,sclera ,cornea ,the cell body , rods ,and cones , and ganglion cells .The skeletal muscle  is elongated contiuous fibers , with nucleated striations . The cardiac muscle has a hugh number of thin cells , spindled shaped with overlapping ends . It contracts , and propels blood into circulation .

The Classes of Joints

I learned in class on yesterday from Chap. 8 ,the concept of the classes of joints . An ex. of an fibrous joint is sutures of the skull . Cartilaginous joints have cartilage , and are in the ribs .The synovial joints contains synovial fluid covered with hyaline cartilage called articular cartilage which provides smooth surface where the bone surface . The function of the synarthroses =no movement. Amphiathroses =little movement ,and diathroses =means free movement .

Action of an Odorant Binding to Menbrame of Olfactory Hair /Chap 15

I learned the concept of that airborne molecules enter the nasal cavity and are dissolved in the fluid covering the olfactory epithelium .These molecules are are odorants . The plasma membrane of the olfactory hair , unstimulated , the gate stys closed . An odorant binds to a receptor ,activating the "G" protein . The a ,B,and y come aloose , the" a"  subunit binds to and activates adeny;late cyclase.Adenylate cyclase catalyzes the conversion of ATP to AMP[cAMP] .cAMP opens the ion channels , such as sodium and calcium . Ions cause depolarization of the nueron . This is what causes us to be able smell so many different things.

The Location of the ANS receptors

When you had the class to break off into groups and help each other to learn the location of the ANS receptors , was very helpful .The drawing on the board demostrated that 1] the somatic nerve which the skeletal is the target has one synaspe releases ACH ,which binds to a nicotinic receptor. 2] The autonomic nerve releases ACH to the adrenal gland  , then releases epinephrine and norepinephrine into the bloodstream. 3] The sympathetic division releases ACH causes NE , which relaeases norepinephrine into the adrenal glands . 4] Then there's the parasympathetic division that releases ACH muscarinic is released into the heart . I've learned that  the sympathetic and parasympathetic  neve endings one of the two transmitters. If it secretes ACH it 's a cholinergic , if it secretes norepinephrine it's an adrenergic neuron . I see how they play the neurotransmittor role .

The Formation of the neural tube

Dr. Platt this is my understanding of the formation the neural tube . The central canal and ventricles produce the neural plate [ which forms from the ectoderm ] .The neural fold forms as ridges along the embryo , actually making an fold, and causing the middle of the fold to become a groove [neural groove]. The neural crest then makes the sensory autonomic neruons in the PNS , melanocytes , facial bones and dentin of teeth . This happens because the neural crest breaks away from the folds , meeting at the midline to form the neural tube .The nueral tube then becomes the  brain and the spinal cord . Thank goodness , this concept was relatively simple , and the illustration on page 440 is very good .

Divisions of the brain and thier functions

The brain divisions include the brainstem , which connnects the spinal cord to the cerebrum ; consists of the medulla oblongata ,pons and midbrain ,with the reticular formations scattered throughout the three regions , is in the location of cranial nerve nuclei . The medulla oblongata is the pathway for ascending and descending nerve tracts ; center for several important reflexes [e.g. ,heart rate ,breathing , swallowing , vomiting].The pons contain ascending and descending nerve tracts ; relays information between the cerebrum and cerebellum ; site of reflex centers .The midbrain contains ascending and descending nerve tracts ; serves as a visual nerve center ;part of auditory pathway . The reticular formation is scattered throughout the brainstem ; controls cyclic activities , such as the sleep -wake cycle . Another division of the brain is the cerebellum , which controls muscle movement and tone ; governs balance , posture ; regulates extent of intentional movement iinvolved in leaaarning moter skills. The diencephalon another part of the brain consists of the thalmus ; which is like a call center determining where signals go for information .Then there is the subthalmus . which contains nerve tracts and nuclei , the epithalmus contains nuclei responding to sleep, visual awareness , amd body cycle .Then there the hypothalmus which is the moter control center for maintaining homeostasis , and regulating endocrine function . The cerebrum conscious perception ,thought , and conscious motor activitiy ; can override most other systems. The cerebrum consists of the basal nuclei , which controls muscle activityand posture ; largely inhibits unintentional movement when at rest . The other part of the cerebrum , the limbic system is an autonomic response to smell , emotion , mood ,memory , and other such funtions .

Ion movement through the plasma membrane

During my attempt to get to some understanding of Chapter 11 ,  I see that ion movement through the plasma membrane is the movement of sodium out of the cells requires energy [ATP] , and when calcium binds to proteins in ion channels , the diffussion of sodium into the cell is inhibited . Specific ion channels regulate the diffusion of sodium through the plasma membrane .