Intro to physiology and homeostasis Flashcards
What are the components of connective tissues?
- Cells such as fibroblasts, adipocytes, mast cells, plasma cells, macrophages and infiltrated white blood cells during inflammation
- Matrix containing protein fibres and ground substances like water and a variety of small and large molecules
What are the responses to heat exposure?
- Decreased muscle tone (micro constriction)
- Skin vasodilation
- Sweating
What is positive feedback?
When change in controlled variable is further enhanced to accelerate the initial process
What are the functions of the skin?
- Protection: skin barrier impedes passage of most materials into body
- Participate in immune response
- Melanin production by melanocytes
- Temperature regulation
What are the 2 types of connective tissues?
- Connective tissue proper
- loose: more cells, less protein fibres
- dense: mainly densely packed collagen fibres and fewer cells - Special connective tissues: bone, blood and cartilage
What are the 4 physical processes of heat gain/loss?
Radiation, conduction, convection and evaporation
What is the main structure of the skin?
- Epidermis: epithelial cells
- inner layer: rapidly dividing
- outer layer: flattened and dead - Dermis: mainly irregular dense connective tissue
- rich in collagen and elastin fibres, blood vessels and nerve endings - Hypodermis
- loose layer of connective tissue
- place where most body fats are stored
What are the 3 types of epithelial tissues?
Squamous, columnar and cuboidal in simple or stratified arrangement
What are the homeostatic conditions?
- Concentration of nutrients
- Concentration of waste products
- Concentration of O2 and Co2
- Concentration of salt and electrolyte
- pH
- Temperature
- Volume and pressure
How is body temperature controlled?
By thermoregulatory center in the hypothalamus that operates on a set point
What are the components of negative feedback?
Sensor > afferent pathway > integrating center > efferent pathway > effector
What is the basement membrane made up of?
- Basal lamina: rich in collagen, laminin, proteoglycan and glycoproteins secreted by epithelial cells
- Reticular lamina: rich in collagen fibres secreted by fibroblasts
What are the responses to cold exposure?
- Shivering
- Vasoconstriction
- Brown fat activity
What is the function of the cuboidal epithelium?
- Cube shaped
- Function: absorption, secretion and excretion
- Lines kidney tubules, salivary and pancreatic ducts
What are the 4 types of tissues?
Muscular, epithelial, connective and nervous
What are the 3 sides of epithelial tissues?
- Apical surface (open surface)
- Basal surface: connected to basement membrane
- Lateral surface: connected by tight junctions, adheren junctions and gap junctions
What are the functions of connective tissues?
- Connect cells and organs together
- Provide strong flexible support to tissues
- Stores body fluids and nourishes cells and organs
- Fill spaces, stores body fats and provides cushion
- Site of immune response
- Involved in wound healing, tissue remodelling and cancer metastasis
What is negative feedback?
When change in controlled variable triggers a response which opposes change, driving the variable in opposite direction of initial change to maintain dynamic constancy
What are the components of neural tissues?
- Neurons that function to generate and transmit electrical signals
- Supporting cells
What is the feed forward mechanism?
Change that occurs in anticipation of a change in a controlled variable
What are the 3 types of muscle tissues?
- Skeletal muscle: long striated cells with multiple nuclei
- Cardiac muscle: branching, striated cells, fused at plasma membranes
- Smooth muscle: long spindle shaped cells, each with one nucleus
What is the function of squamous epithelium?
- Flattened with prominent, protruding nucleus
- Function for filtration and diffusion
- Lines oral cavity, pulmonary alveoli and glomerulus of kidney
What is homeostasis?
The maintenance of stable conditions of internal environment to maintain dynamic constancy
How does the skin take part in immune response?
- Keratinocytes produce inflammatory cytokines and kill microbes
- Langerhands and granstein cells serve as APCs
- Connective tissue important site for immune response
What is the body organisation and tissue types?
- Cells: smallest unit of life
- Tissues: consist of cells with similar structures and functions
- Organs: Consist of at least 2 primary tissues with different functions
- System: when organs from different body regions perform related functions
What is the difference between simple and stratified arrangement?
- Simple: one cell thick, specialised for transport
- Stratified: composed of number of layers; specialised for protection
What is the function of the columnar epithelium?
- Taller column shaped cells
- Function for absorption, secretion and excretion
- Lines digestive track and uterine tubes
What are the mechanisms regulating homeostasis?
- Intrinsic control: regulated within organ
- Extrinsic control: regulatory mechanisms initiated outside organ alters activity of organ; accomplished by endocrine and nervous systems
- Negative and positive feedback, feed forward
