What are the basic cellular functions? (select all that apply)
Growth
Reproduction
Metabolism
Forms protective barriers in tissues and can specialize to absorb or secrete compounds
Epithelial cells
Forms glands and secretes substances (e.g. mucous, hormones, enzymes)
Secretory cells
Stores fat as triglycerides
Adipose cells
Formed in bone marrow and delivers oxygen throughout the body. Limited lifespans. No nuclei or mitochondria.
Red blood cells
Forms the bones of the skeletal system that strengthen and support the body. Includes osteoclasts cells that degrade and create bone.
Bone cells
Creates extracellular material that holds cells together in tissue. Can specialize to absorb or resist external forces.
Connective tissue cells
Conducts electrical signals and controls muscle contraction and the five senses.
Nerve cells
Controls movement of the skeleton, heart, and other organs. Includes specialized proteins that allows them to generate motion.
Muscle cells
What are cell junctions?
Types of membrane proteins that facilitate cell-to-cell attachments
Which specialized proteins do epithelial and endothelial cells need?
Junction complexes
What are the cells that line the insides of blood vessels?
Endothelial cells
What are the cells that line the cavities and surfaces of organs?
Epithelial cells
What do epithelial cells rest on?
Basement membrane
What is the basement membrane?
An extracellular matrix that separates epithelial cells from connective tissue
Can phospholipids move across tight junctions?
No
Tight junctions separate the plasma membrane into which two domains?
Apical and basal
Is the apical surface the top or bottom of the cell?
Top
Which of these regulates paracellular transport?
Tight junctions
What is paracellular transport?
The transport of material between cells
Adherens junctions use receptor proteins called what?
Cadherins
What do cadherins do?
Bind to cadherins on neighbouring cells
Where are adherens junctions found? (select all that apply)
Neural synapses
Cardiac muscle cells
What do hemidesmosomes consist of?
Half a desmosome complex
What is the function of desmosomes?
Structural integrity
What do hemidesmosomes do?
Attach to the basement membrane of epithelial cells to attach them to the extracellular matrix
Which are the proteins of the junctional complex?
Tight junctions, adherens junctions, desmosomes
Gap junctions are built of two halves that connect to cross what?
The intercellular gap
Why are gap junctions imortant in cardiac muscle contractions?
Without them, heart muscle cells would not be able to contract at the same time
Which cell junction attaches to the basement membrane?
Epithelial cells
Which protein allows the transfer of ions and small molecules between cells?
Gap junctions
Which protein in the junctional complex links cells tightly via cadherins?
Adherens junctions
Which protein in the junctional complex snaps cells together that are under high amounts of physical stress?
Desmosomes
What is the extracellular matrix (ECM)?
A network of molecules that fills the spaces between cells
What kind of sheet does the basement membrane consist of?
Collagen sheet
Which proteins are involved in the ECM? (select all that apply)
Collagen
Elastin
Fibronectin
Laminins
Proteoglycans
What does the triple helix in collagen do?
Forms fibrils
What do fibrils form?
Collagen fibers
What is fibronectin?
Glycoproteins that connect cells collagen matrices for cell adhesion
Fibronectins are expressed as dimers and bind to...?
Integrins
When fibronectin interacts with the cytoskeleton and its dimers straighten, what happens?
Fibrils appear at the cell surface
What is the function of elastin?
Tissue elasticity
What type of regions allows elastin to be returned to original shape after being stretched?
Hydrophobic and hydrophilic regions
What is the function of laminins? (select all that apply)
Provides an adhesive substrate for cells
Strengthens the ECM
Which ECM protein forms a web-like network that has much strength in many directions?
Laminins
What are proteoglycans?
Hydrated gel resistant to compressive forces
What do proteoglycans consist of?
A protein polypeptide core attached to sugar residues
Which bodily structure is proteoglycan important for?
Cartilage in joints
Where are specialized epithelial tissues found? (select all that apply)
Skin
Glands
Digestive tract
Where do endocrine glands release their secretions?
The bloodstream
Why don't endocrine glands have ducts?
Because their cells release secretions directly into the bloodstream
How do exocrine glands release their secretions?
Through ducts
What are the functions of the epithelial cells that line the GI tract? (select all that apply)
Form digestive glands
Coordinate transportation
Produce and excrete proteins
Why do glycosylated proteins form a mucus layer?
To protect epithelial cells from themselves and the acidic environment
When the contents of a vesicle are released from a cell into extracellular space as the vesicle fuses with the plasma membrane.
Exocytosis
Are the epithelial tissues that form digestive glands exocrine or endocrine?
Exocrine
What do the epithelial tissues that form digestive glands do?
Produce and release enzyme proteins and hydrochloric acid to break down food
Nerve tissues are composed of nerve cells as well as...?
Glial cells and schwann cells
How do nerve cells use ion concentrations in electrical signalling
Differences in concentration create electrical potential for cellular communication
What are the 3 types of muscle?
Skeletal, smooth, and cardiac
Which type of muscle lines the digestive tract and large blood vessels?
Smooth
Which type of muscle lines areas of the body that require contractile movement?
Smooth
The ECM in the lungs are rich in which kind of connective tissue?
Elastin
What is an organ?
A structure of two or more tissue types
What is the inside of the stomach lined with?
Epithelial tissues
What lines the outside of the stomach under the epithelial tissue?
Muscle tissue
Why does the smooth muscle in the stomach contract?
To mix the stomach contents and push it into the intestine
What does nervous tissue in the stomach do?
Controls muscle contractions and gland secretions
Name all the tissues that compose the stomach. (hint: the 4 main tissue types)
epithelial, muscle, connective, nervous
How many body systems are in the human body?
11
What composes the cardiovascular system?
Heart, blood vessels, blood
What do blood vessels do?
Transports the blood
What does the blood do?
Carries nutrients to the cells and removes their wastes
What is homeostasis?
The ability of a cell/organism to regulate and maintain its internal environment
What does the homeostatic control system do?
Maintains set points in the body
What are the 3 parts of the homeostatic control system?
The sensor, the integrator, the effector
Which part of the homeostatic control system detects an environmental variable?
The sensor
Which part of the homeostatic control system compares a variable's value to its set point?
The integrator
Which part of the homeostatic control system initiates change to restore the set point?
The effector
Shivering is an example of homeostatic control. Why do we shiver when cold?
To contract the muscles to release heat
What is the body's set temperature?
37°C
What is the range of the body's temperature?
36-38°C
When a temperature different from the set point is perceived in the thermoregulation centre, what do the effectors do? (select all that apply)
Causes blood vessels in the skin to constrict to minimize heat loss
Contracts skeletal muscles for shivering to produce heat
What is an intrinsically controlled system?
When the sensor, integrator, and effector of a system are all located in the tissue
What is an extrinsically controlled system?
When the regulatory mechanisms are outside of the tissue or organ
What is an example of an intrinsically controlled system?
Skeletal muscle during exercise
Are most of the body's systems intrinsically or extrinsically controlled?
Extrinsically
What is homeostatic feedback?
When an effector causes a change that is sensed by a sensor
What is negative feedback?
A change in the environmental parameter that causes the effector to intiate a response in the opposite direction
What is positive feedback?
When the effector causes changes that amplify the intial signal
True or False: Positive feedback is homeostatic
False
What is an example of positive feedback in the human body? (select all that apply)
Breastfeeding
Childbirth contractions
Blood clotting
In temperature regulation, if positive feedback did occur would it increase or decrease body temperature?
Decrease
Is blood clotting positive or negative feedback, and is it intrinsically or extrinsically controlled?
Positive feedback, intrinsically controlled
In childbirth, pressure from the fetus on the cervix sends signals to the brain that releases hormones, causes contractions, and puts more pressure on the cervix. What type of feedback is this and is it intrinsic or extrinsic?
Positive feedback, extrinsically controlled