A&P 2 Exam 3: Cells and Hormones

Baroreceptor:

• measure BP at different locations

• Found at aortic arch (dominant) and carotids

Cardiac Inhibitory Center:

• decreases HR (parasympathetic)

Cardiac Excitatory Center:

• increases HR (sympathetic)

Vasomotor Center:

• Located in medulla

• vasoconstriction and vasodilation, sets vasomotor tone (S-ANS)

Vasomotor Tone:

• degree of contraction and relaxation of smooth muscle in blood vessel walls

Norepinephrine and Epinephrine:

• cause vasodilation of vessels to skeletal and cardiac muscle

• cause vasoconstriction of vessels to other organs

• increases heart rate and blood pressure

Angiotensin II (AII)

• Secreted by liver if BP is low

• Short term: global vasodilation, increases BP

• Long term: increases thirst, causes a rise in aldosterone levels, keeps BV consistent, increased BP

Atrial Natriuretic Peptide:

• produced by cardiac muscle cells located in the right atrium of heart

• Short term: vasoconstriction, increase BP

• Long term: blocks aldosterone, kidneys push salt to urine, increase urination, decrease BV and decrease BP

Leukocytes (WBCs):

• reside within lymph nodes

• help to prevent diseases and infections in the body

Interstitial fluid (ISF):

• A fluid that surrounds the cells in tissues, providing them with nutrients and removing waste products

Innate Immune Cells:

• The first line of defense against pathogens, including various types of leukocytes like macrophages and natural killer cells. They provide a rapid, non-specific response to infections.

Pattern Recognition Receptors (PRR):

• Molecules found on immune cells that detect specific patterns associated with pathogens, triggering immune responses.

Natural Killer Cells (NKs):

• A type of innate immune cell that identifies and destroys infected or cancerous cells by recognizing stress signals on their surface.

Mast Cells:

• A type of innate immune cell that plays a crucial role in allergic reactions and defense against pathogens by releasing histamine and other mediators.

Prostaglandins:

• Activate neurons causing pain, can be blocked by aspirin

Complement Proteins:

• Part of the innate and adaptive immune system

• Involved in inflammation and cell lysis

• Their activation leads to a cascade of protein interactions that amplify the immune response

Membrane Attack Complex (MAC):

• A structure formed by the complement system that creates pores in the membranes of target cells, leading to cell lysis and death

Adaptive Defenses:

• Use humoral response (B-cells) and cell mediated response (T-cells)

Innate Defenses:

• Use physical barriers and internal cell-based responses

Humoral:

• B-cell

• Type of adaptive immunity

• produce antibodies that can go into the blood or the lymph, activation on the MAC (easier to find and attack)

Cell-Mediated:

• T-cells

• Adaptive Immunity

• Virus is inside the cell (hidden and harder to attack)

Major Histocompatibility Complex (MHC):

• Large, set of genes that encode cell-surface proteins

Pattern Recognition Receptors (PRR):

• Encoded host proteins that act as key sensors in the innate immune system

Neutrophils:

• phagocyte

• Movement of WBC through intact capillary walls into surrounding tissue to fight infection and injury

• Diapedesis

Macrophages:

• Phagocyte

• Resident and roaming “big eaters”

• Bodies primary defense to engulf and digest pathogens, cellular debris and dead cells

Natural Killer Cells (NKs):

• Kill cancer and virus-infected cells

• Apoptosis

• Needs PRR

Naive Lymphocyte:

• A mature B or T cell that’s left the bone marrow but has not encountered their specific target antigen

Positive Selection:

• If the B/T cell binds only weakly to just 1 antigen (self antigen)

Negative Selection:

• If B/T cell binds to and cannot release from a self antigen, killed not released

T-Cells:

• located in the blood

• can attack infected cells and those that are not in the blood

• fight invaders without antibodies by using memory T-cells and effector T-cells

CD4+ T Helper Cells:

• Major cytokine releases

• Help activate CD8+ and B lymphocytes

• Help turn immune system off

CD8+ T Cytotoxic Cells:

• Require activation

• memory effectors

• Kill by perforin ring and injects granzymes into cell

MHC I:

• Found on all cells

MHC II:

• Found just on APCs