Kulkarni 3

He did quite a good microscope tutorial for those present. No notes on it beyond what he posted.

Showing basic tissues and organs in notes and slides today. Organs chosen based on the common cancers: breast, colon, lung, prostate, skin (see chart he handed out in class).

Nerve tissue
PNS is peripheral nervous system. CNS is central nervous system.
4 types of supporrting cells in CNS are listed.
Neuron structure given on slide.
Myelin sheath in CNS is from oligodendrocytes. In the PNS the sheath is produced by Schwann cells. In CNS, you cannot regenerate the axon after nerve injury. Optic nerve is CNS, so there is no regeneration if it is damaged. PNS- axon regenerates.
Nissl granules- rough ER. To see processes (parts that stick out of cells like little feet), must use different stains.

Last slide p7- myelin sheath around axon. Myelin sheath has gaps- nodes of Ranvier- to help impulse travel faster.
Page 8 slide 1
Axon in middle, hazy area is myelin sheath, then Schwann cell is seen as a darkly-staining nucleus.
Skipping cardiovascular for lack of time.
Lymphatic capillaries are larger than blood capillaries. Lymph is filtered in lymph nodes.

Endothelium looks like epithelium, but is flattened. Developmentally different.
(in cardiovascular system)
Lymphatic tissues:
Mostly skipped.
Moving to 3rd part of lecture:
Organs
Take midline section- cut through nasal cavity. Larynx main purpose is to carry air, not to talk. Nasal cavity and oral cavit are connected connect to pharynx, which leads to larynx anteriorly, to trachea, to bronchus which keeps dividing. Tertiary bronchi divide until they form bronchioles. When you take a section of lung, you see alveoli, bronchi, blood velssels, alveolar duct to bronchiole.
Bronchiole muscles regulate air resistance and constrict in asthma. Can breathe in, not out.

Alveolar epithelium is of 2 types- squamous for gas exchange, cuboidal for surfactant to reduce surface tension. Macrophages are there to engulf foreign material.

GI tract
Oral cavity to pharynx to esophagus posteriorly. Large intestine is 1.5 m long. We will focus on large intestine. Serosa is outer peritoneal lining.
Lining epithelium in large intestine is cuboidal with lots of goblet cells.

Skin- 2 layers- epidermis and dermis. Epidermis has 5 layers. See slide.
Stratum corneum is a keratinized layer.
Some cells have halo in epidermis under the microscope- the clear cells tend to be melanocytes which can transform into melanoma.

Most of the notes were labelling bits on slides. See someone who was there.